Bo Teza Tu Cristian

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"Gh. Asachi" Technical University

of IasiCivil Engineering Department

PROJECT, CONSTRUCTION AND QUALITY CONTROLIN HIGHWAY INFRASTRUCTURES

A study of earthworks on IP4, IC24 and IC25 roads

Ing. Botezatu Costel-Cristian

July 2006


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"Gh. Asachi" Technical University

of IasiCivil Engineering Department

PROJECT, CONSTRUCTION AND QUALITY CONTROLIN HIGHWAY INFRASTRUCTURES


Master Student:

Ing. Botezatu Costel-Cristian

Coordinator:Paulo Antnio Alves Pereira, Ph.D. - Full ProfessorRadu Andrei, Ph.D. - Full Professor

Tutors:Hugo Manuel Ribeiro Dias da Silva, Ph.D. - Assistant ProfessorJoel Ricardo Martins Oliveira, Ph.D. - Assistant Professor

This master project was developed during a Leonardo da Vinci program in Portugal at

Universidade do Minho during a five months period

July 2006


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I

PROJECT, CONSTRUCTION AND QUALITY CONTROL IN HIGHWAY

INFRASTRUCTURES


INDEX

1. Introduction ................................................................................................................. 12. Main stages of road infrastructure concessions .......................................................... 4

2.1.Concession model (e.g. PORTUSCALE organisation) ....................................... 42.2.Design phases ...................................................................................................... 62.3.Construction phases ............................................................................................. 9

3. Project of Highways .................................................................................................. 163.1.Design of Highways .......................................................................................... 163.2.Safety plan ......................................................................................................... 183.3.Environmental documents ................................................................................. 213.4.Affected Services ............................................................................................... 233.5.Expropriations .................................................................................................... 253.6.Pavement loads .................................................................................................. 28

3.6.1.Traffic ........................................................................................................ 283.6.2.Weather conditions (temperature, water precipitation) ............................. 29

3.7.Pavement materials ............................................................................................ 323.7.1.Earthwork materials ................................................................................... 323.7.2.Aggregates ................................................................................................. 353.7.3.Bituminous binders .................................................................................... 373.7.4.Hydraulic binders ...................................................................................... 493.7.5.Stabilized soils ........................................................................................... 423.7.6.Bituminous mixtures .................................................................................. 443.7.7.Mixtures design ......................................................................................... 46

3.8.Pavement design ................................................................................................ 493.8.1.Pavement design methods ......................................................................... 493.8.2.Subgrade .................................................................................................... 513.8.3.Temperature and weather .......................................................................... 533.8.4.Drainage ..................................................................................................... 54

4. Pavement construction technology ........................................................................... 574.1.Earthworks ......................................................................................................... 57


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II

4.2.Drainage works .................................................................................................. 604.3.Flexible Pavement layers ................................................................................... 63

4.3.1.Sub-Base ................................................................................................... 63

4.3.2.Base .......................................................................................................... 644.3.3.Binder and Surface course ........................................................................ 66

4.4.Interface preparation .......................................................................................... 694.5.Asphalt plant ...................................................................................................... 714.6.Engineering Structures ....................................................................................... 76

4.6.1.Retaining walls .......................................................................................... 764.6.2.Junctions .................................................................................................... 804.6.3.Viaducts ..................................................................................................... 814.6.4.Bridges ....................................................................................................... 82

5. Quality Control & Quality Assurance ....................................................................... 855.1.Definitions ......................................................................................................... 855.2.Quality documentation ....................................................................................... 875.3.Quality Control Plan minimum requirements .................................................... 875.4.Study for the final characteristics of the pavement ........................................... 89

5.4.1.Roughness .................................................................................................. 905.4.2.Skid resistance ........................................................................................... 915.4.3.Deflection .................................................................................................. 94

5.5.Final documentation submittals ......................................................................... 956. Case Study Earthworks .......................................................................................... 97

6.1.Project ................................................................................................................ 976.2.Materials .......................................................................................................... 1026.3.Construction technology .................................................................................. 1066.4.Quality Control & Quality Assurance ............................................................. 115

7. Conclusions ............................................................................................................. 123Bibliographic references ............................................................................................... 125


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Project, Construction and Quality Control in Highway Infrastructure Botezatu Costel-Cristian

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Chapter 1

INTRODUCTION

This project refers to a portion of the new highway build in the Porto area. This road is

part of the Concession Scut do Grande Portothat congregates a group of freeways and

groups road associates in the area of Grande Porto, integrated in the National Road

Plan, with the identification reference in the location inserted in Figure 1.1:

IP4: N de Sendim

IP4: N de Sendim / guas Santas

VRI: N do Aeroporto (IC24) / IP4

IC24: Freixieiro / Aeroporto

IC24: Aeroporto / N da Maia (IP1)

IC24: N da Maia (IP1) / Alfena

IC24: Alfena / N da Ermida (IC25)

IC25: N da Ermida (IC24) / Paos de Ferreira

IC25: Paos de Ferreira / N da EN 106

IC25: N da EN 106 / N do IP9

EN 207: N do IP9 / Felgueiras (EN 101)

Figure 1.1 Highway preview


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Some of the roads that constitute the Concession are already in service and they will be

object of increase of the number of lanes, these being:

IC25 Paos de Ferreira/N da EN106, with the approximate extension of 6.3

km;

IP4 N da Sendim, with the approximate extension of 1 km;

IC24 Freixieiro/Airport, with the approximate extension of 4 km;

IC24 Airport/N da Maia (IP1), with the approximate extension of 3 km;

IC24 N da Maia (IP1)/Alfena, with the approximate extension of 2 km.

The remaining ones, to build from ground, integrate the following sub-sectors:

IP4 Sendim/guas Santas, with the approximate extension of 8.7 km;

VRI Knot of the Airport (IC24)/IP4, with the approximate extension of 3.5 km;

IC24 - Alfena/N da Ermida (IC25), with the approximate extension of 9 km;

IC25 - N da Ermida (IC24)/Paos de Ferreira, with the approximate extension of

10.1 km;

IC25 - N da EN106/N da IP9, with the approximate extension of 9 km;

EN 207 - Knot of IP9/Felgueiras (EN 101).

Of the group of freeways to conceive and to build, the passage of IP4 among Sendim

(N da Sendim) and guas Santas (in the divergence among the freeways A3 and A4) it

will work as a ring road for the urban area of Porto, complementing the distribution of

traffic today effectuated for VCI, Circumvallation and IC24.

In the intermediate area of the sector of IP4, starting from the knot established with EN

13 (designated Via Norte); IP4 can distribute traffic for south, in direction to Porto, and

for north in direction to Maia.

This sector of IP4 is subdivided in two sub-sectors designated for:

IP4 - Sendim/Via Norte and

IP4 - Via Norte/guas Santas,

the last one being visited thru a 4 month period and the object of the present study

project.


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In agreement with the available elements of traffic it was considered already, in the

contest phase and in the negotiation phase for attribution of the Concession, the

adoption of a profile with four roads in each sense.

In the terms of the Contract of Concession it is foreseen in the year of 2006 the entrance

in service of IP4 with a profile of 2 x 3 roads (with a separation of 7.60 m) occupying a

total platform 36.60 m.

In 2015, in agreement with the same contract, be introduced then more two roads in the

interior area, making a profile of 2 x 4 roads, being reduced the sifter to 0.60 m of

width, however, the total width of the platform stays in 36.60 m.

The temporal macro objectives established are next:

Project Phase Concluded: December 2004

Expropriation Phase concluded: December 2004

Construction start: November 2003

Construction deadline: September 2006

Negotiation volume of ACE with the Concessionaire was fixed at 545.26 millions of

euros (Project, Construction, traffic counting equipment, expenses and coordination) for

a total length of the constructed highway of 55.6 km.


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Chapter 2

THE MAIN STAGES OF ROAD INFRASTRUCTURE CONCESSIONS

2.1 Concession model (PORTUSCALE organization)

The main entities involved in the concession process will be presented in this first part

of the report, as well as their contractual relationships and obligations. In Portugal, the

Portuguese State, represented by the EP Estradas de Portugal (Portuguese Road

Administration), is the entity which attributes the concessions through its Department of

Concessions.

The entities, to which the concessions have been given, are called Concessionaires. In

Portugal, four of these entities are the following: i) AENOR for the Northern

concessions; ii) LUSOSCUT CP for Costa de Prata concessions; iii) LUSOSCUT

BLA for Beira Litoral e Altaconcessions; iv) LUSOSCUT GP for Grande Porto

concessions. These types of concessionaires have, as associated members, several

Construction Companies and some Banks, which finance the construction.

The contractors (ACE) are the entities responsible for the execution of the Project and

Construction of the Highways. The contractors of the Concessionaires previously

described are these ones: i) NORACE for the Northern concessions; ii) VIANOR for

Costa de Prataconcessions; iii) LUSITNIA forBeira Litoral e Altaconcessions; iv)

PORTUSCALE for Grande Porto concessions (used as an example in this project

report). All these four entities have construction companies as associated partners.

The construction companies associated with the ACE are called Subcontractors and areresponsible for the constructions of the concessions several roads. The ACE Designers

are the entities responsible for the conception and elaboration of the project for the

highways construction.

In this concession model, the road administration (in this case EP) gives a Concession

Contract (CC) to the Concessionaire to regulate their relationships (rights and duties),

which can be divided into three sub-contracts with the following objectives: i)


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conception, design and construction of the highway; ii) financial support of the

construction; iii) maintenance and exploitation of the conceded highways.

This concession model is commonly used when the government (in this case, the

Portuguese Road Administration) does not want to use directly huge amounts of money

to support financially the construction of a new highway. Thus, the State gives the

highway in concession for a certain period (in this case, thirty years). During this

period, the Concessionaires have the duty of maintaining the highways at a good service

level and the benefits of the road exploitation (by receiving money for each car which

goes by on the conceded highway, paid directly by the road users Highway toll or by

the Portuguese State SCUTS).

The Project and Construction Contract (PCC) regulates the relationship between the

Concessionaire (e.g. LUSOSCUT GP) and the ACE (e.g. PORTUSCALE) and it has as

objective the conception, design and construction of the highway by PORTUSCALE in

a fixed and global price system, before a certain deadline of conclusion. This contract

represents an integral Back to Back of the concessionaire obligations before the State,

concerning the conception, project and execution of the highway. This contract is a part

of the Concession Contract.

The conception and project contract between PORTUSCALE and Designers has as

objective the elaboration of the required projects to start building the highway. The

relationships between PORTUSCALE and the companies responsible for the highway

conception and design (Coordinators, Verifiers and Designers) are regulated by the

project contract.

The sub-contractors objective is the execution and conclusion of all the construction

works for the several highway sections. The sub-contract agreement controls the

relationship between PORTUSCALE and Subcontractors, thus being an entire Back to

Back of the PORTUSCALE obligations before the concessionaire and, consequently,

before the State, concerning the construction of the different highway sections.


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The sub-contractor has the responsibility of constructing the highway sections in

conformity to the project and before the established deadlines, always by following

strictly the safety and environmental rules.

PORTUSCALE (ACE) duties are: the coordination of the different agents of the

constructing process, to assure the reliability of the projects, procedures and inspections.

PORTUSCALE activity consists of the design and execution phases, which are included

in the PCC (Project and Construction Contract) and are planed out in the construction

programme. This is also named Studies and Projects Plan (in Portuguese, Plano de

Estudos e Projectos PEP) and it discriminates the duration of the construction and

design phases.

The concessionaire assures convenient relationships with the road administration (EP)

and the financing Banks, being an intermediary and advocate of the ACEs (Portuscale)

rights near them. They assume the position of Owner of the Works. The road

administration (EP) has the responsibility of carrying out the expropriations and giving

approval to all the necessary studies and projects to the concession.

The concession phases (design, construction and exploitation) are integrant parts of the

CC (Concession Contract) and comprise:

the Construction Programme, which encloses the studies and projects,expropriations

and execution of the road works;

the Programme of Major Maintenance and Enlargements, which also encloses the

respective project.

2.2 Design phases

Essentially, a project is formed by a specific number of volumes, presented in Table 2.1.

Each of them has a descriptive memoir and drawings with specific details for each type

of work. A RECAPE (in Portuguese,Relatrio de Conformidade Ambiental do Projecto

de Execuo), which is a report about the environmental conformity of the execution

project, must be attached to the end.


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Table 2.1 Contents of a projectVolume Name of the volume

1 Synthesis2 Introduction and survey approval3 Geological and Geotechnical studies

4 General lay-out5 Junctions6 Re-establishments, utilities and parallel roads7 Drainage8 Pavement9 Landscape integration

10 Safety equipments11 Signalling12 Counting and classification of traffic equipment and closed TV circuit13 Telecommunications

14 Lighting15 Fences16 Affected services17 Normal concrete works (passageways over and under highways)18 Special concrete works (viaducts and long bridges)19 Other projects20 Expropriations21 Project with measures to reduce the impact on environment22 Assistance and maintenance centre23 Service and station areas

24 Tunnels

The project organization is coordinated by the PORTUSCALE Project Administration,

with the main objective of guaranteeing that the studies and projects are executed before

the deadline, with the requested quality and as estimated in the budget. The relationship

between the main entities involved in the project is presented in Figure 2.1.

Executive commission

Project Management Contractors

Project Coordination

Designers Verifiers

Figure 2.1 Organization of the main entities involved in the project phase


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The beginning of the construction depends on the design phase, concerning three

fundamental points:

delivery/approval of the expropriations project to begin the expropriations process, of

the responsibility of EP, which should be carried out within a period of 6 months;

delivery/approval of the complete projects of the affected services reestablishment, to

allow the contract with the several entities (responsible for the services) on time and

their immediate removal at the beginning of the construction works;

delivery/approval of the execution project or, at least, the necessary designs for the

first construction works.

The expropriation project is carried out by PORTUSCALE (by proposing an amount of

money for the expropriated lands), but it is essential that EP (the State) approves the

expropriations project and carries out the expropriations (by paying the money to the

land owners). After the EP approval of the expropriation project, there is a period of 6

months to complete these expropriations.

If an owner does not accept the offer of the State, the land can be taken out, according to

a law which declares that if a highway is of national interest, the land needed to

construct that highway can be taken out immediately. When an inhabited house is in the

land, the expropriation can only be carried out after the habitants leave their house, after

mutual agreement between owners/habitants and EP, concerning the value of the land

and the house. Sometimes, the decision about the expropriation can be taken in court of

law, thus extending the period of expropriation more than 1 year. If the inhabited house

is rented, the habitants can be compensated with money or with a new house. The

decision about the compensation can also be taken in court of law, which will send an

evacuation order after the final verdict.

Works usually begin before the expropriation phase ends without the possibility of

demolishing the houses or closing some road accesses, thus harming the normal

execution of the highway construction. In this case, if the works deadline is exceeded

by expropriation causes, PORTUSCALE is compensated by the State, concerning these

delays (e.g. by extending the exploitation period).


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The affected services are mainly formed by: gas pipes, water pipes, electricity cables,

telecommunications and sanitation. All the projects of the affected services

reestablishment are carried out by Portuscale design companies. The

telecommunications and electricity works are done by the companies responsible for

those services, which are paid afterwards by the LUSOSCUT GP concessionaire. The

gas, water and sanitation works are performed by the sub-contractor companies which

work for Portuscale.

Basically, concerning affected services, PORTUSCALE has the role of mediator, by

trying to solve the problems with the several companies, by offering the services as

quickly as possible (to avoid delays at the construction work) and by asking the fair

prices for the works.

The affected services main stages are the following: i) 1st phase (between the

conclusion of the preliminary study and the beginning of the geometrical lay-out)

Seeking information about the services in entities and companies; ii) 2ndphase (at the

beginning of the execution project) Emission of the project of the services cadastre;

iii) 3rdphase (until the end of the execution project) Emission of the project of the

services relocation.

2.3 Construction phases

The organization of the construction processes is coordinated by the Postuscales

construction administration, whose main objective is to guarantee the execution of the

construction works before the deadline, with the requested quality and as estimated in

the budget.

The Postuscale activity during the construction phase consists, fundamentally, in the

achievement of the following objectives:

to guarantee the accomplishment of the contractual deadline through an adequate

Planning of the Construction and by following the work evolution;

to guarantee a final product with the requested quality through inspections and tests

and through adequate solutions to the non-conformity situations;

to control and to process the work invoices to the sub-contractors and to theconcessionaire;


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to guarantee hygiene and safety conditions at the work place;

to follow the environmental and archaeological occurrences at the highway work

without affecting the normal work evolution;

to guarantee the correct management of the insurance policy.

Concerning the planning of the Highway construction, the contractor must emit and

submit to Portuscale an Initial Work Plan until the 30thday after the reception of the

execution project (with the limit of 10 days before the consignation). Once approved,

this work plan becomes the base document of the construction. The initial work plan is

constituted by: i) descriptive and explanatory memory; ii) work programme with

physical and financial chronological diagrams; iii) charts of equipment needs and labour

force; iv) project of the work yard and plans of accesses, circulation and signalling;

v) organisational diagram; vi) expropriations chronological diagram.

The Portuscale has two procedures to follow-up the construction work, namely

Actualizations of the Work Programme (performed monthly) and Revisions of the Work

Programme (performed every three months).

Concerning the Actualizations of the Work Programme, the sub-contractor must

schedule the initial work programme monthly and submit it to Portuscale until the 10 th

day of each month, with the analyses which justify the work delays and the respective

measures to recover the lost time. These Actualizations must always show the initial

work plan or the last approved revision of the plan, registered as "Baseline", by

underlining the essential sequence of procedures.

Concerning the Revisions of the Work Programme, it must be revaluated every three

months or every time Portuscale considers it is necessary. The sub-contractor must

submit the Reviewed Work Programme 30 days after it has been required by Portuscale.

Those Revisions must explain the work delays and the respective measures and

deadlines to recover the lost time, with the indication of the necessary equipment and

the labour force reinforcements to respect the work deadline established in the initial

contract. The essential sequence of procedures must be underlined.


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To allow the weekly planning of Portuscale activities and the appropriate monitoring of

works, the sub-contractors are requested to submit to ACE a fortnightly work

programme, which contains information about the current or new work fronts within the

analysed period, the stop points (for Quality Control and Health and Safety Assessment)

and all the necessary interventions, regarding the Affected Services. The Work

Programme for the next fortnightly period must be submitted fortnightly, by the

Sub-contractor to the Portuscale, until the penultimate working day of every week, with

the indication of the active work fronts, in order to allow the coordination of the activity

of the several work agents.

In order to avoid eventual delays in the beginning of works, it is necessary to guarantee

the delivery of several documents among the different parts involved in the construction

of the Highway concession (Lusoscut GP, Portuscale and Sub-contractors). Portuscale

assumes the commitment of delivering the group of documents presented in Table 2.2 to

the Sub-contractor at the consignment date (this is independent from previous deliveries

of the same documents in other phases of the process).

Table 2.2 Documents emitted by Portuscale and submitted to the Sub-Contractor

Documents Time limitApproved execution project UndefinedModels for the emission of the measurement reports, listing the articlesand unitary costs settled with the Sub-contractors

Undefined

Sub-contractors quality manual UndefinedThe verification of the supporting polygonal (road line) UndefinedThe verification of the expropriations polygonal (area) UndefinedHealth and Safety Plan UndefinedCD with the Work Quality Manual, sub-contract agreement and contractof project and construction

Undefined

Application of laboratorial management Highways Undefined

The preparation, compilation and approval of the documents, presented in Table 2.2,

imply the intervention of other entities and documents, such as those presented in

Table 2.3, which the Sub-contractor must deliver to Portuscale.

The documents to be delivered by the Concessionaire (Lusoscut GP) to Portuscale, and

vice-versa, are presented respectively in Tables 2.4 and 2.5 (some documents do not

have an explicit deadline).


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Table 2.3 Documents emitted by the Sub-Contractor and submitted to Portuscale

DocumentsDelivery time limit relatively

to the beginning of works

Surrounding conditions until 45 days beforePreliminary work programme until 45 days before

Preliminary chart of labour force until 45 days beforePreliminary chart of equipment needs until 45 days beforeInformation concerning preliminary communication until 12 days beforeCrises management Emergency plan until 10 days beforeSafety management Organisational Diagram until 10 days beforePlan of works with special risks until 10 days beforeProject of the work yard and plans of accesses, circulationand signalling

until 10 days before

Sub-contractor quality plan until 30 days beforeWorking procedures until 60 days before

Definitive working plan until 10 days before

Table 2.4 Documents emitted by the Concessionaire and submitted to PortuscaleDocuments Time limit

Document with specifications approved by EP Undefined

Execution project approved by EP Undefined

Table 2.5 Documents emitted by the Portuscale and submitted to the ConcessionaireDocuments Time limit

Sub-contractor quality Manual UndefinedInspection and test plans Undefined

Sub-contractor quality plan Undefined

Descriptive report Undefined

Definitive working programme 28 days after consignment

There are some fundamental definitions related to inspection, tests and non-conformity

solution which must be understood, namely the following:

Inspections and Tests Plan or PIE (in Portuguese,Plano de Inspeces e Ensaios) a document which contains a compilation of specifications with verifications, which

demonstrate the conformity of an activity with the work quality manual, with the

execution project of each highway section and with the working procedures of the

sub-contractor;

Documental analysis an evaluation of the previous documents necessary to begin

an activity, by verifying the conformity of the materials, equipments, constructive

methods or the work plan proposed by the sub-contractor;


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Stop point situation of the work, in which the sub-contractor needs a special

authorization from Portuscale to begin or continue the activity;

Nonconformity (NC) a product which does not conform to the specifications;

serious or imminent danger situations;

Anomalya failure which occurs during the work execution. If it is not corrected, it

will lead to a NC;

Correcting action or AC (in Portuguese,Aco Correctiva) an action which

eliminates the causes of nonconformity, anomaly or another unwanted situation in

order to avoid its repetition;

Derogation (DRG) a written authorization to use or deliver a product which does

not conform to the specifications.

Concerning inspections and tests, the sub-contractor effectuates them, according to the

traditional control methodology and warranting the total accomplishment of the PIE.

The Portuscale has the obligation of verifying if they are effectively and correctly

accomplished. The PIE defines the inspections and tests to be necessarily performed by

the sub-contractor and those to be performed by Portuscale. It regulates the inspection

of Portuscale and presents the responsible persons for every inspection action. The PIE

must also present how to evaluate (and who evaluates) the qualitative service of thesub-contractor, by showing explicit rules to accomplish the referred inspection. It refers

the registers and how to register the tests and inspections.

The Portuscale will evaluate the sub-contractors system of quality assurance and will

execute its own inspections and tests on a sampling basis (10 to 20%), which is

considered to be representative of every activity, in order to validate the sub-

contractors tests and inspections. In the case of a stop point, the Portuscale interventionwill always consist in a previous audit of the sub-contractor (by obtaining from the

sub-contractor previous copies of the inspections registers). Moreover, Portuscale can

carry out the same verifications to confirm those done by the sub-contractor.

Another phase of the construction process is the invoice, in which the Concessionaire

(Lusoscut), Portuscale and Sub-contractors interfere. The methodology adopted in the

process of obtaining the authorization to emit the monthly works invoice is

schematically illustrated in Figure 2.2.


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Figure 2.2 Methodology used in the monthly invoice process

Concerning safety and prevention, Portuscale has the aim of establishing the activities

which should be adopted in the planning and implementation of prevention and safety atworkplace, namely by applying the Health and Safety Plan which allows getting higher

levels of health, safety and comfort.

This principium is applied to: i) all the project and construction works of the highway

sections and roads associated with the concession; ii) all the areas considered to be work

yards (lands or places which support the works execution); iii) all the areas near the

work yards and workplaces (in order to control the risks of human accidents).

1 Sub-contractorElaboration of the monthly report of

measurement

2 Sub-contractorSend, before the 22ndday, the monthlyreport of measurement to Portuscale

- Measurement report- Quantities justifications- Declarations of quality

- Measurement report- Declarations of quality

Protocol

Invoice

Start

Protocol

Invoice

End

3 PortuscaleTo verify the quantities constructed on the

month

4 PortuscaleElaboration of the monthly report of

measurement (Project + Construction)

5 Portuscale

Send the monthly report of measurementto Lusoscut

6 LusoscutApproval and emission of the payment

certificates of the monthly report ofmeasurement (Project + Construction)

7 PortuscaleSend the invoice to Lusoscut

8 PortuscaleSend the approval and payment

certificate of the monthly report ofmeasurement of the sub-contractor

9 Sub-contractorSend the invoice to Portuscale


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The agents responsibilities and the Portuscales acting in terms of safety are described

in a specific document (Manual Prprio) by DPS (Department of Prevention and

Safety).


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Chapter 3

PROJECT OF HIGHWAYS

3.1 Design of Highways

Geometric design is primarily concerned with relating the physical elements of the

highway to the requirements of the driver and the vehicle. It is mainly concerned with

those elements which make up the visible features of the roadway, and it does not

include the structural design of the facility. Features which have to be considered in

geometric design are, primarily, horizontal and vertical curvature, the cross-section

elements, highway grades and the layout of intersections.

Proper geometric design will inevitably reduce the number and severity of highway

accidents while ensuring high traffic capacity with the minimum of delay to vehicles.

While these are the main factors to be considered, care must also be taken that the

highway presents an aesthetically satisfying picture to both the driver and the onlooker.

The aim should be to design a facility that blends harmoniously with the topography and

not one that leaves an ugly scar on landscape.

The design for capacity defines the ability of a road to accommodate traffic under given

circumstances. Factors which must be taken into account in determining the governing

circumstances are the physical features of the road itself and the prevailing traffic

conditions. Poor physical features which tend to cause a reduction in capacity are

narrow traffic lanes (3.65 m are now accepted as being the minimum), inadequate

shoulders (too narrow shoulders alongside a road cause vehicles to travel closer to the

centre of the carriageway), side obstructions (poles, bridge abutments, retaining walls orparked cars that are located within about 1.75 m of the edge of the carriageway

contribute towards a reduction in the effective width of the outside traffic lane) and

imperfect horizontal or vertical curvature (result in inadequate sight distance).

Unlike the physical features of the highway, which are literally fixed in position and

have definite measurable effects on uninterrupted and interrupted traffic flows, the

prevailing traffic conditions are not fixed but vary from hour to hour throughout theday. The flows at any particular time are a function of the speeds of vehicles, of the


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composition of the traffic streams and the manner in which the vehicles interact with

each other, as well as the physical features of the roadway itself. As we can see in

Figure 3.1, the traffic varies in composition (trucks, small cars, etc.) and in

concentration in different directions. The term concentration used the same as the term

density is defined as the number of vehicles occupying a unit length of a traffic lane at

a given instant. Concentration is usually expressed in vehicles per kilometer.

Figure 3.1 A3 Highway in Portugal

The vertical alignment design refers to the design of the tangents and curves along the

profile of the road. The primary aim of this profile design is to ensure that a

continuously unfolding ribbon of road is presented to the motorist so that hisanticipation of directional change and future action is instantaneous and correct. Roller-

coaster types of profile should be avoided as they are dangerous as well as aesthetically

unpleasing. In vertical design, gradients should be the most important factor taken in

consideration since grades of up to about 7 % have relatively little effect on the speeds

of passenger cars but the speeds of commercial vehicles are considerably reduced when

long gradients, with grades in excess of about 2 % are included (the speed of traffic is

often controlled by the speeds of the slower commercial vehicles). Most highwayauthorities now accept a gradient of 4 % as being the maximum desirable on major

highways; hence this criterion is usually a controlling feature of highway design.

Cross-section elements are those features of the highway which form its effective width

and which affect vehicle movement. The constituent parts, as we can see in Figure 3.2,

of primary interest are the number and width of traffic lanes, the central reservation,

shoulders, camber of the carriageway and, where necessary, the side slopes of cuttingsor embankments.


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Figure 3.2 Typical transversal profiles

Horizontal curvature design is one of the most important features influencing the

efficiency and safety of a highway. Improper design will result in lower speeds and a

lowering of highway capacity. The importance of curve design upon safety is reflected

by the accident statistics, which shows that the sharper the curve the greater the

tendency for accidents to occur. The maximum comfortable speed on a horizontal curveis primarily dependent upon the radius of the curve and the super elevation of the

carriageway. In addition, vehicle speeds and safety on high-speed roads are aided by the

presence of such features as extra carriageway widths at the curves themselves and the

insertion of transition curves between straights and curves, some examples of such

curves can be seen in Figure 3.3.

Figure 3.3 Horizontal curves in Portugal highways

3.2 Safety plan

In the decree of Ministry of the Social Safety and Workare few points that explain the

legislation in this matter, described shortly forward. Safety's conditions in the developed

work in temporary construction yards are frequently very deficient and they are in the

origin of a preoccupying number of the serious work accidents and fatalities, provoked

above all by falls in height, crushes and entrench. Face to the imperious need of


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reducing the professionals risks in the sectors with larger accident rates, the agreement

about work conditions, hygiene and safety in the work and combat of the mortalities,

have been reviewed and improved the safety specific norms in the work in the sector of

the building site and public works, as well as the reinforce of the means and of the fiscal

activity in this and in other sectors more affected for the incidence of work accidents

and professional diseases.

Plan of safety and health constitutes one of the fundamental instruments of the planning

and of the organization of the safety in the work in temporary construction yards or

movable, to the disposal of the coordination system of safety, what justifies the need to

improve the respective regulation. The plan should be elaborated starting from the phase

of the project of the work, being later developed and specified before passing to the

execution of the work, with the opening of the construction yard. The owner of the work

will name safety's coordinator through in work of a written declaration that identifies it

before all the intervening in the construction yard. Safety's coordinator in work and the

safety and health plan are not obligatory in works of smaller complexity in than the

risks are usually more reduced. However if there is a issue to execute those works

determined by works that implicate special risks, the entity performer owes records of

procedures of safety that indicate the necessary measures of prevention to execute those

works.

The prevention of the professional risks depends of the knowledge of the technical

characteristics of the work, so that can be identified the potential risks and adopt work

processes that avoid them or minimize, insofar as possible. The works in construction

and mainly in civil engineering domain consist in basely in excavation, earthmoving,

construction, enlargement, modification, demolition, repairing, restore, conservationand cleaning of buildings, assembly and disassembly of prefabricated elements,

scaffolds, cranes, etc.

Safety's plan and health should foresee measures appropriate to prevent the special risks

for the safety and the current workers health, these risks being those that implicate:

Exposing the workers to entrenchment, of sinking or of fall in height (Figure 3.4),

particularly worsened by the nature of the activity or of the used means, or of the halfinvolving of the position, or of the situation of work, or of the construction yard;


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Figure 3.4 Work on a viaduct

Working in the proximity of electrical lines of average and high tension (in Figure

3.5 can be observed power lines which is achievable by machines that are working in

their proximity);

Figure 3.5 Electrical lines in construction area

Working in roads, rail or road that are in use, or in they proximity (in Figure 3.6 can

be observed works near a rail track and a highway that are not being closed during

construction faze);

Figure 3.6 Works carried out under circulation


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Exposing the workers to chemical risks or biological hazards of causing professional

diseases;

Exposing the workers to ionized radiations, when the designation areas are

obligatory to be controlled or watched;

Dive with equipment or that implicate drowning risk;

Work in wells, tunnels, galleries or caisson of compressed air;

Use of explosives, or they originate derived risks of explosive atmospheres (in Figure

3.7 we can see works with explosives the textile materials are applied to reduce the

risks of flying debris, also reducing dust emission);

Figure 3.7 Works involving explosives

Assembly and disassemble of prefabricated elements or other, whose form,

dimension or weigh expose the workers to serious risk.

Any other work can be included here if the owner of the work, the author of the project

or any of the coordinators of safety, consider to be capable of constitute serious risk for

the safety and health of the workers.

3.3 Environmental documents

Environment Sector elaborates a PGA - Plano de Gesto Ambiental (Plan of

Environmental Administration), for each section of highway that begins. This document

is the base of the functions of Sector and it is a brief summary of the most important

aspects of RECAPE (Report of Environmental Conformity of Project of Execution) that

the Builders have to accomplish completely. In the intention of minimizing theenvironmental impact during the planning phase and execution of the Work, Portuscale


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gives to the Builder the Plan of Environmental Administration, in our case of the Lot 2 -

IP4 through NORTE/GUAS SANTAS.

This document makes the synthesis of the environmental documents of Execution

Project of the lot in cause, making possible the planning of the procedures, of the

processes and of the resources to use to develop, to implement and to monitor his

implementation efficiently in all of the phases of the work from the consignment to the

temporary reception on the part of the Concessionaire. This report, it should be

permanently available in the work shipyard.

Before begin of the work must be give to the builder documents such as Plan of

construction yard, Integrated plan of Administration of Residues (management of

coming residues of the shipyards like dumps, mud, asphalts, oils, lubricants, fuels,

chemical products and other residual materials of the work), Plan of Environmental

Emergency (actions in case of accident with it spills or emission of pollutant substances

considering all the possible risk situations), Official report to the Population (inhabitants

located inside of a strip of 200m of the limit of the plan should be informed on the

occurrence of the construction operations), Reports of Rising water table or Flow of the

existent Underground Receptions along the tracing, Plan of Monitoring (Hydro

Resources and Waters Quality, Sound Environment, Wells, Spring and Holes), Plan of

landscape recuperation of the Areas of construction yard and other Degraded Areas,

Machines Park and Temporary Access roads.

Also during the construction phase are documents that must be giving to builder like

Projects of Execution of Fencing, Projects of Execution of Loans, Reports of

Attendance of water table, Rising or Flow of the existent Underground Receptionsalong the Plan (the Builder should give to PORTUSCALE in the end of each season, the

Report of Monitoring of the water table of the existent underground receptions along the

continuity plan), Report of Monitoring of the Emissions of the Central of Manufacture

of Bituminous Mixtures, Report of Monitoring of the Emissions of the Central of

Manufacture of Bituminous Mixtures, Reports of Monitoring (Hydro Resources and

Waters Quality, Sound Environment, Wells, springs and Drillings) and Implementation

of Landscape Integration Project.


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To minimize the environmental impact the location of construction yards preferentially

should coincide with areas already waterproof/paved that are not occupied (former

industrial areas without activity, abandoned quarries or other works, etc). In case they

have to be built, these should be waterproof properly and be located in areas away from

places with lines of water and receptions. After the conclusion of the works, the soils of

the no paved areas of the construction yard and of vehicles and machines circulation

should be clean and objective of de-compaction of the soil, for form recover more

quickly of their natural characteristics. Eventual noxious effects of the discharge in

natural waters of residual waters can be avoided through the construction of appropriate

systems for the respective drainage and treatment. It should be preceded with an

installation that collects and treats the waters that contemplates the industrial and

domestic effluents and for the water from machines and vehicles wash should be used a

clearing tank. In the case of bituminous mixtures plant, the kettle of the headquarters,

the deposits of fuel, the asphalt deposits, deposits of bitumen and emulsions, they

should be put on concrete flagstones with a retention wall and for the filer in excess

should suffer a specific treatment with the use of humidification that will transform the

powder in mud.

Before the beginning of the work should be mentioned the place of bituminous asphalt

plant (won't be located in the proximity of habitation areas or of isolated houses) and all

the deposit and loan places should be presented and identified before execution, to

Portuscale, for evaluation.

3.4 Affected services

As was mentioned in chapter 2, affected services are formed by gas pipes, water pipes,electricity mains, telecommunications and sanitation. These services can interfere with

the highway line and because of that they must be repositioned or relocated. Some of

these services cannot be repositioned until the expropriations are finalized (Figure 3.8,

Figure 3.9 and Figure 3.10), the working being carried out around those services.

Telecommunications and electricity works are being done by the company that holds

them and are paid afterwards by the concessionaire.


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Figure 3.8 Power lines that constitute a part of affected services

In Figure 3.8 can be observed some power lines that couldnt be repositioned, because

dismantling them will affect the houses after those lines. Also in Figure 3.9 can be

observed a telephone line which is still in service during construction and serves the

houses near by construction site.

Figure 3.9 Telecommunication line obstructing construction

The gas, water and sanitation are being effectuated by the constructing companies. In

Figure 3.10 left can be seen two red lines that symbolize the gas pipe crossing the area

where the highway will be and in Figure 3.10 right can be observed a sanitation conductwhich is disaffected (in the central of the image).


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Figure 3.10 Gas pipe (left) and sewage (right) pipe

Portuscale its having in affected services a role of mediator, because some companies

can ask more money on some works or they want to use expensive materials or they can

delay the work progress by dont doing these repositioning at time. Affected services

stages begin with geometrical lay-out followed by issuance of cadastral project (its at

the beginning of execution project) and at the end with the issuance of services

repositioning project.

3.5 Expropriations

In this matter will be developed a memory ho seeks to present the topographicalcharacteristics concisely, cadastral, cultural and infra-structural, situations of urban

occupation, industrial and commercial, and other relevant situations that condition and

they influence the lands affected for the work. The plan can grow on some lands with

agricultural occupation in the periphery of urban agglomerates, the urban center, houses

that will be expropriated, and workshops. Inside of the territory under jurisdiction of the

municipal districts the portions interfere in urban areas are predominantly residential,

industrial, green areas, architectonical, equipment areas, etc. In Figure 3.10 can be seenhow the line of the highway (the area hatched with red) crosses an area with houses

positioned in construction zone. These houses couldnt be expropriated on time so the

construction began before their demolition. The roads which are visible in the picture

are roads constructed for trucks and vehicles of the construction yard and will be

demolished when they will not be necessary.


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Figure 3.10 Highway crossing a populated area (guas Santas)

Also for this type of problems must be presented an evaluation bases, intend to justify

the unitary values of lands, improvements, indemnity and other compensations to apply

in the work. In the determination of the prices to apply are consulted market indicators,

as well as the values practiced by the expropriate entity or for another one with identical

purpose in several projects in the area were the work will be developed. Presented

values must be calculated as "fair indemnity", acceptable on the part of expropriated, for

the expropriations to develop with the minimum of conflicts. To reduce costs in some

areas can be applied some solutions like gabions and air-placed concrete (Figure 3.11)

in zones of cut and fill. These solutions have the advantage of occupying a small area of

land on the sides of highway and they are used to stabilize the slopes. Usual retainingwalls can be also used but they occupy a bigger area during construction and are more

difficult to build.

Figure 3.11 Solutions for reduce of expropriations area

Expropriation project begin with topographical delimitation of areas in cause, this

project belonging to Portuscale, who makes the calculation for the lands and propose

these sums of money to the government because he will be paying these lands, but the


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government approve these money and effectuates the expropriations. A delimited

expropriation area can be seen in Figure 3.12, the zones marked with red being those

which must be expropriated.

FREG. DE GUAS SFREG. DE S. MAMEDEINFESTA

Figure 3.12 Areas of expropriation object

The government has 6 months at disposal to effectuate these expropriations after he will

approve expropriation project. When the owners of the houses object to expropriate

dont accept the offer of government, then the land can be taken by reason of a law in

which is define that if a work is in national interests, then this land can be taken

immediately, but when on the land is an inhabited house, they must wait until the trial is

over. However, if the house is rented, the court can send an evacuation decision, phase

which can still take 1 year. In some cases the works begin along those houses without

demolish them or closing access roads, going forward only few stages (for example

earth works, as we seen in Figure 3.10). If the deadline is exceeded by expropriate

causes then Portuscale is absolved by these delays.


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3.6 Pavement loads

3.6.1 Traffic

The traffic to be considered includes axle loads, the number of load repetitions, tire

contact areas, and vehicle speeds. Trucks for example can have single axle with single

tires, single axle with dual tires or tandem axles with dual tires and special heavy-duty

trucks, tridem axles consisting of a set of three axles, each spaced at a particular

distance.

In the design of flexible pavements by layered theory, only the wheels on one side, say

at the outer wheel path, need to be considered; where as in the design of rigid

pavements by plate theory, the wheels on both sides, are usually considered.

Loads are the vehicle forces exerted on the pavement (for example by trucks, small cars,

etc.). Since one of the primary functions of a pavement is load distribution, pavement

design must account for the expected lifetime traffic loads. Loads, the vehicle forces

exerted on the pavement, can be characterized by tire loads, axle and tire configurations,

load repetition, traffic distribution across the pavement and vehicle speed. Tire loads are

the fundamental loads at the actual tire-pavement contact points. While the tire contact

pressure and area is of concern, the number of contact points per vehicle and their

spacing is critical. As tire loads get closer together their influence areas on the pavement

begin to overlap, at which point the design characteristic of concern is no longer the

single isolated tire load but rather the combined effect of all the interacting tire loads. In

the matter of trafficdistribution on any given road, one direction typically carries more

loads than the other. Furthermore, within this one direction, each lane carries a differentportion of the loading. The outer lanes often carry the most trucks and therefore are

usually subjected to the heaviest loading.

Regarding Vehicle speed in general, slower speeds and stop conditions allow a

particular load to be applied to a given pavement area for a longer period of time

resulting in greater damage. If mix design or structural design has been inadequate, this

behavior is sometimes evident at bus stops (where heavy buses stop and sit while


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loading/unloading passengers) and intersection approaches (where traffic stops and

waits to pass through the intersection).

Pavement structural design requires a quantification of all expected loads a pavement

will encounter over its design life. This quantification can be usually done in two ways,

equivalent single axle loads (ESALs) or load spectra.

The first approach converts wheel loads of various magnitudes and repetitions ("mixed

traffic") to an equivalent number of "standard" or "equivalent" loads based on the

amount of damage they do to the pavement. The commonly used standard load is the

18,000 lb. equivalent single axle load. Using the ESAL method, all loads (including

multi-axle loads) are converted to an equivalent number of 18,000 lb. single axle loads,

which is then used for design. A "load equivalency factor" represents the equivalent

number of ESALs for the given weight-axle combination. As a rule-of-thumb, the load

equivalency of a particular load (and also the pavement damage imparted by a particular

load) is roughly related to the load by a power of four (for reasonably strong pavement

surfaces). For example, a 36,000 lb. single axle load will cause about 16 times the

damage as an 18,000 lb. single axle load. Buses tend have high load equivalency factors

because although they may be lighter than a loaded 18-wheeler, they only have two or

three axles instead of five.

The second approach characterizes loads directly by number of axles, configuration and

weight. It does not involve conversion to equivalent values. Structural design

calculations using load spectra are generally more complex than those using ESALs

because loading cannot be reduced to one equivalent number. Both approaches use the

same type and quality of data but the load spectra approach has the potential to be moreaccurate in its load characterization.

3.6.2 Weather conditions (temperature, water precipitation)

A pavement must function within its environment. The environment can vary greatly

across the country at any one time and it can also vary greatly throughout time at any

one place. Environmental variations can have a significant impact on pavementmaterials and the underlying subgrade, which in turn can drastically affect pavement


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performance. The key environmental parameters of concern are typically temperature,

frost action and moisture. Temperature acts on pavements in two principal ways. First,

temperature extremes can affect asphalt binder rheology and second, temperature

variations which can cause pavement to expand and contract. Asphalt binder rheology

varies with temperature. Therefore, estimated temperature extremes and their effects are

a primary consideration when selecting an appropriate asphalt binder. For flexible

pavements, older asphalt binder grading systems did not directly account for

temperature effects and thus various empirical systems and thumb-rules were

developed.

Pavements, like all other materials, will expand as they rise in temperature and contract

as the fall in temperature. Small amounts of expansion and contraction are typically

accommodated without excessive damage, however extreme temperature variations can

lead to catastrophic failures. Flexible pavements can suffer transversal cracks as a result

of excessive contraction in cold weather as can be observed in Figure 3.13.

Figure 3.13 Cracks from excessive pavement contraction

Frost action can be divided into "frost heave" and "thaw weakening". "Frost heave" is

an upward movement of the subgrade resulting from the expansion of accumulated soil

moisture as it freezes, while "thaw weakening" is a weakened subgrade condition

resulting from soil saturation as ice within the soil melts.


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Frost heaving of soil is caused by crystallization of ice within the larger soil voids and

usually a subsequent extension of this ice to form continuous ice lenses, layers, veins, or

other ice masses. As depicted in Figure 3.14, an ice lens grows and thickens in the

direction of heat transfer until the water supply is depleted or until freezing conditions at

the freezing interface no longer support further crystallization.

Figure 3.14 Formation of ice lenses in a pavement structure

As the ice lens grows, the overlying soil and pavement will heave up potentially

resulting in a rough, cracked pavement (see Figure 3.14).

Figure 3.14 Frost Heave

Frost heave occurs primarily in soils containing fine particles (often termed frost

susceptible soils), while clean sands and gravels (small amounts of fine particles) are


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non-frost susceptible. Thus, the degree of frost susceptibility is mainly a function of the

percentage of fine particles within the soil.

Thawing can proceed from the top downward, or from the bottom upward, or both.

How this occurs depends mainly on the pavement surface temperature. During a sudden

spring thaw, melting will proceed almost entirely from the surface downward. This

type of thawing leads to extremely poor drainage conditions. The frozen soil beneath

the thawed layer can trap the water released by the melting ice lenses so that lateral and

surface drainage are the only paths the water can take.

3.7 Pavement materials (identification, behavior, tests)

3.7.1 Earthwork materials

"Backfill Foundation" means the ground upon which said backfill shall be executed.

The following areas are distinguished on the backfill being its geometry defined on the

design:

Lower part of backfill (EB) - Is the area where the foundation lays (usually it is

considered to be formed by the two first backfill layers). Whenever the clearing

works have been previously carried out the layers situated bellow the natural ground

level shall also be included.

Body - means the backfill part situated between the base and the top of the backfill.

Top part of backfill (ET) - Is the area (about 40-85cm) which supports the capping

layer and includes the pavement foundation and influences its behavior.

Capping layer - It is the last "layer" of the backfill. Its function to grant the pavement

foundation good conditions not only in what the service conditions are concerned but

also the assembly conditions on site which must allow an easy and adequate

compaction of the first pavement layer and thus assuring the appropriate conditions

for the site traffic. For construction reasons the capping layer can be formed by one

or several layers. The top of the backfill and the capping layer form the pavement

foundation.

Sides - Is lateral area of the embankment body that includes the slopes and can

occasionally work as a stabilizer.


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The materials to be used for the backfill shall be the ones defined on the design and

should be imported or from site excavations. The borrow pits chosen by the Contractor

should be previously submitted to the Supervision for approval. The materials to for the

backfill must be preferably insensitive to water (which determines that the percentage of

the material passing the sieve nr. 200 can not exceed 30%) especially when there is the

possibility of floods and/or soaking the adjacent land. Also materials to be used must

have geologic characteristics which allow them to reach immediately after their

assembly the strengths, in particular the mechanical, assuring the relevant requirement.

This means that materials must be correctly spread and compacted bearing in mind that

is necessary a maximum dimension ho allows the layers to be leveled and that its

thickness is compatible with the power of the rollers used.

The soils or materials to be used shall be clean of branches, leaves, trunks, roots, herbs,

rubbish or organic debris and the maximal dimension of the material elements to be

applied shall not be higher than 2/3 of the layer thickness once compacted. At the sides

materials compatible with the estimated slopes geometry shall be used so that instability

and or erosion risks can be avoid. When by economic and/or environmental reasons it is

absolutely necessary to reuse currents soils (fine and sensitive to water) for backfill

construction, with high water contents in its natural state, treatment techniques can be

used (in situ or in the plant) with lime or hydraulic binders can be used in order to

guarantee the traffic conditions and to reach the required conditions for its placement on

site.

The materials for backfill are (under a grading point of view) soils, rock materials (rock

fill) and hardcore materials. Under this specification soils mean the materials that mustfulfill the condition in which the material retained by the sieve 19 mm (3/4") ASTM to

be less than 30%. Regarding the water content, in its natural state, can be observed:

Soils incoerentes: 0.8 WopmWnat1.2 Wopm

Soils coerentes: 0.7 WopnWnat1.4 Wopn

where:

Wopm- optimum water content referring to the Modified Proctor test

Wopn- optimum water content referring to the Normal Proctor test


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Whenever this requirement is not verified on the currents soils case treatment

techniques with lime or lime combined with cement can be used.

Considering its reuse for backfill and also the definition of the assembly conditions the

rocky materials can be characterized as to determine their strength characteristics,

fragility and changeability. The material to be used in rock backfill should come from

the excavation areas and shall be homogeneous, of high quality, without waste, organic

matters or any other harmful substances.

Under a grading point of view the hard core materials shall be those showing a

continuous grading and obeying to the following grading conditions:

Material retained by sieve 19 mm (3/4") ASTM - between 30% and 70%;

Material passing the sieve 0,075 mm (no 200) ASTM - between 12% and 40%;

The maximum dimension of the blocks shall not exceed 2/3 of the thickness of the

layer after compaction not to be superior to 0.40 m.

These materials which are formed by a mixture of soils and rock and that usually come

from blasting shall comply with the required specification for each fraction, rock or soil.

Rocky materials (rock fills) are not allowed at the completion of the "earth fills"

execution. It is also forbidden the use of the "sandwich" type continuous and alternated

use of different materials in order to guarantee a uniform and continuous behavior of the

embankment. On the top of backfill to a thickness between 40 to 85 cm soils with

higher geotechnical characteristics shall be used.

Sandwich embankments are those using different materials whose characteristics and

location are defined in the design. Examples that can be given: the fill where the body is

formed by materials of the hardcore soils type and the sides by rocky materials or the

backfill body built with soils, the sides built with treated soils. Characteristics admitted

in design regarding properties content are pure compression, point load test; porosities,

volume and expandability must be checked on site. Special concern must also be given

to crushing strength, wearing at a moister environment.

Technical fill are those to be carried out in difficult access areas where it is impossibleto operate normally with current spreading and compaction equipment. Among other


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technical fills are those near abutments or any other buried structure type as well as

those near retaining walls, small or big diameter hydraulic passages, cattle creeps, etc.

3.7.2 Aggregates

One definition of an aggregate is that it is a material such as broken stone, slag, gravel,

sand or other like which, when held together by a binding agent, forms a substantial part

of such materials as concrete, asphalt, coated macadam or like. This definition means

that any hard material, whether it is natural or artificial, may be classified as an

aggregate. In practice, however, the materials suitable for use as road aggregates may be

limited in a particular area.

By far the majority of road aggregates are formed from natural rock. Geologists have

classified rocks into three main groups, based on their method of origin; these are

known as igneous, sedimentary and metamorphic rocks.

Igneous rocks were formed at or below the earth's surface by the cooling of molten

material, called magma, which erupted from, or was trapped, beneath the earth's crust.

Igneous rocks formed at the earth's surface when the magma came into contact with the

atmosphere are called extrusive rocks, while those formed below the earth's surface are

intrusive rocks. Extrusive magma cooled rapidly at the earth's surface and as a result the

rocks formed are very often glassy or vitreous (without crystals) or partly crystalline

and partly vitreous. In contrast with the extrusive rocks, the intrusive rocks are entirely

crystalline, having been formed as a result of the magma cooling slowly under the

protective cover of the earth's crust. Igneous rocks can also be separated on the basis of

their being acidic or basic depending of silica (SiO) content. In preparing bituminousmixtures, acidic aggregates can be difficult to coat with binder in contrast with the

hydrophobic or water-hating aggregates formed from a rock such as basalt.

Sedimentary rocks were formed when the products of disintegration and/or

decomposition of any type of rock were transported and redeposit, and then

consolidated or cemented into a new rock type. Sedimentary rocks may be sub-divided

by various means, but from the highway engineer's point of view the most convenientone is that based on the predominant rock mineral. This allows three main rock sub


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classifications, the calcareous, siliceous and argillaceous groups. Calcareous rocks were

formed as the result of great thicknesses of the remains of small marine animals being

deposited on the ocean floors. It is most suitable as an aggregate for bituminous

surfacing. The predominant mineral is calcite, CaCO, and this renders the rocks basic

and in general it is most suitable as an aggregate for bituminous surfacing. Some types

of calcareous rocks, are however too porous to be used as road aggregates.

Siliceous rocks were formed from deposits of sand and silt which became lithified as a

result of pressure by overlying strata, or by the deposition of cementing material

between the grains. The predominant mineral in these rocks is either quartz or

chalcedony, both SiO, and this may tend to make adhesion between these aggregates

and bituminous binders relatively difficult.

Argillaceous rocks are those who formed when fine-grained particles of soil were first

deposited as clays or mud and then consolidated by pressure from overlying deposits.

They are rarely used as road aggregates, and never in bituminous surfacing. Also

included under the title of sedimentary rocks are the natural gravels and sands.

Metamorphic rocks are igneous or sedimentary rocks which, as a result of being

subjected to tremendous heat (thermal metamorphism), or heat and great pressure

combined (regional metamorphism), were transformed into new types of rock by the re

crystallization of their constituents. Metamorphism in any particular instance may have

been aided by the presence of permeating solvents which worked through the rock and

promoted new mineral growth. Metamorphic rocks which were altered by heat alone are

in considerable demand as road aggregates.

Aggregates can also be divided in groups like basalt, flint, gabbro, granite, gritstone,

hornfels, limestone, porphyry, quartzite and schist group. Each one of these groups has

a specific number of members.

The aggregates used in construction in general must be clean, hard, not due to changes

under the action of weather agents, of uniform quality and free of decomposed

materials, of organic matter and other harmful substances. The use of non-traditionalgranular materials, such as demolition products, crushed concrete, slag of steelworks,


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not foreseen in the project of the highway, may be approved as long as the proposal for

its use is duly justified.

The concept of nominal dimension (d/D) means that it is admissible up to 10% of the

material retained in the sieve of larger dimensions (D) and up to 10% of the material

that passes through the sieve of smaller dimensions (d); however, the addition of the

two percentages must be less than 15%.

The use of crushed pebbles in bituminous mixture it is conditioned by the use of an

additive in the bitumen, in order to ensure the adequate adhesion to the bituminous

binder. The checking will be carried out from Marshall Stability tests, before and after

immersion of the Marshall Test specimens in water at 60Cfor 24 h, where the quotient

of the stability values of the normal test and of the post-immersion test should be equal

to or greater than 75% (variant to the test ASTM D 1075). Besides the Marshall test will

have to be carried out the test of passive adhesion, where the mixture of aggregates with

filler and bitumen is placed inside a container with water at 100 C and stirred for 2 min

and by visual observation shall be made an analysis of the percentage of bitumen

displaced from the particles of aggregates. The adhesion shall be considered if there is

no ungluing of the bitumen particles. For mortars and concrete in Portugal the

aggregates must be in compliance with the specification LNEC E 373, where is

mentioned that 50% of the sand must be of siliceous nature.

3.7.3 Bituminous binders

The most careful specifications with regard to the design and construction of a

bituminous road surfacing are of little value if the properties of the bituminous binderused in the design are not adequately controlled. To aid the engineer in ensuring that the

material obtained has the desired qualities, a number of tests have been devised which

attempt to measure various binder properties for particular reasons. As is unfortunately

the case with so many highway engineering test specifications, there are variations from

organization to organization with regard to how exactly these binder tests should be

carried out, although there is general agreement as to their significance. Most usually

tests on binders are those regarding consistency (penetration, viscosity and softening


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point tests), composition (distillation, water content, loss-on-heating, ash content and

solubility tests), specific gravity test andflash and fire point tests.

The material supply on site must always be accompanied by a test bulletin, which

characterizes the fabrication lot. The supplied material must be in compliance with the

given provisions. The characteristics of the bitumen must be in compliance with the

specification LNEC E 80 - Laboratorio Nacional de Engenharia Civil (National

Laboratory of Civil Engineering). The bitumen in use must be of the type defined on the

Road project, normally 35/50 or 50/70 for all bituminous mixtures or 160/220 in the

cases when it is destined to the execution of superficial surfacing or semi-penetrations.

In the case of bituminous mixtures of high module, the bitumen to be used shall in

principle be of the type 10/20 and possibly with additive. The use of bitumen of a type

different from those given will be limited to the implementation of possible proposals

by the Contractor, dully justified and submitted for the approval of the Supervision. The

tests bulletin, which accompanies the supply of the bitumen, must always state the

temperatures at which the material presents the viscosity of 170 20 cSt and of 280

30 cSt.

Modified bitumen used in the production of bituminous mixtures (draining, roughened,

etc.) it is modified with polymers be in compliance with the given provisions. For

example the bituminous binder used in draining bituminous mixtures must have

modifiers that grant to the mixture a smaller thermal susceptibility, a greater flexibility

and to improve other characteristics. These specifications which must be complied for

bituminous binder used in draining bituminous mixtures are:

a) Penetration, at 25 C, 100g, 5s (0.1 mm) 55-70

b) Softening temperature, minimum 55Cc) Fragility point of Frass, maximum -10C

d) Plasticity interval, minimum 65C

e) Viscosity, at 135 C, minimum 850 cSt

f) Stability in storage difference on the value of temperature

of softening, maximum 5C

g) Elastic recovery, at 25 C, minimum 25%


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Fluidized bitumen must have his characteristics in compliance with the specification E

98 of LNEC. The fluidized bitumen to be used in impregnation irrigation of granular

base must be of the type defined on the Paving project, normally MC-30 or MC-70.

The bituminous emulsions can be used in impregnating coats, in tack coats, semi-

penetrations, superficial bituminous surfacing, stabilization of base, curing of base

treated with cement, gluing and impregnation of geo-textiles, as well as in bituminous

mixtures or micro-agglomerates at low temperature. As an example for impregnating

coats of granular base, the emulsion to be used must be a cationic type with low

viscosity and slow failure or for tack coats the emulsion used must be of the cationic

type with sudden failure normally type ECR - 1.

Modified bituminous emulsions must be storage in a system which is provided with the

necessary means to ensure its stability and the non-sedimentation of the bitumen

particles. The distillation residue in this type of emulsions must be obtained by

evaporation at 163 C. The characterization tests of these products must be carried out

in a laboratory, which is certified or approved by the Supervision. Usually these

modified bituminous emulsions are used for tack coats, bituminous micro-agglomerate

at low temperature or superficial surfacing and for gluing and impregnation of geo-

textiles (with the purpose of with the purpose of obtaining an anti-cracking interface).

The emulsion used in tack coats for gluing irrigation between a bituminous layer with

modified bitumen and another bituminous layer must be a bituminous emulsion

modified with the incorporation of adequate polymers, in order to grant a high adhesion

power and the bituminous emulsion used in the gluing and impregnation of geo-textiles

shall be in principle of the cationic type of sudden failure, modified with theincorporation of adequate polymers.

3.7.4 Hydraulic binders

The most used hydraulic binder is without any doubt the cement. Cement is a material

which, if added in a suitable form to a no coherent assemblage of particles, will

subsequently harden by physical or chemical means and bind the particles into a

coherent mass. This definition, which is very broad in scope, allows such diverse


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materials as bitumen, tar and lime to be grouped together under the umbrella of

cement. In road construction these are used mainly in soil stabilization. For this

reason will use the term cement to refer only to the Portland and high-alumina cement

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