Ce122 Presentation

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PAVEMENT DESIGNREPORTERS:

KENT JUSTIN OCENARJENEVA FRANCISCOEZA ESTOPEREZ

JEAN NIKKA SIMON

HAROLD HIQUIANA

introduction

PAVEMENTS-One of the costliest items associated with highway construction and maintenance.-Largely responsible for making U.S. highway system the most expensive public works project under taken by any society.

In the United states:-4.8 million kilometers of highways-45% are not paved.

In the Philippines:-199,950 kilometers of roads-80% are not paved

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introduction

Fundamental functions of pavements:

1) It helps guide drivers by giving them a visual perspective of the horizontal and vertical alignment of the travelled path thus giving drivers information relating to the driver task and the steering control of the vehicle.

2)It supports vehicle roads.3

PAVEMENT TYPES

General Types of Pavement Structures:1) Flexible Pavements2) Rigid Pavements

Variations of the Pavement Types:a) Composite Pavementsb) Continuously Reinforced Pavementsc) Post-Tension Pavements

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PAVEMENT TYPES

A pavements function is to distribute the traffic load stresses to the soil (subgrade) at a magnitude that will not shear or distort the soil.

Typical soil bearing capacities:-Less than 345 kPa (50 lb/in^2)-In some cases, 14 to 21 kPa (2 to 3 lb/in^2)

Typical Weight of Automobiles:-15.5 kN (3500 lb), with tire pressure around 241 kPa(35 lb/in^2)

Typical Weight of Tractor/Semi-Trailer Truck:-355.8 kN (80,000 lb) ,with tire pressure of 690 kPa (100lb/in^2)

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PAVEMENT TYPES

FLEXIBLE PAVEMENTS:-constructed with asphaltic cement and aggregates and usually consist of several layers.

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PAVEMENT TYPES

RIGID PAVEMENTS:-constructed with Portland Cement Concrete and aggregates.

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Pavement system design

PRINCIPLES FOR FLEXIBLE PAVEMENTS:

The primary function of the pavement structure is to reduce and distribute the surface stresses to an acceptable level at the subgrade.

A flexible pavement reduces the stresses by distributing the traffic wheel loads over greater and greater areas, through individual layers, until the stress at the subgrade is at acceptably low level.

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Pavement system design

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Traditional aashto flexible-pavement design procedure

ACCEPTED FLEXIBLE-PAVEMENT DESIGN PROCEDURES:-The Asphalt Institute Method-The National Stone Association Procedure-The Shell Procedure-The Mechanistic-Empirical Pavement Design Guide

AASHTO GUIDE FOR DESIGN OF PAVEMENT STRUCTURES.-Published by American Association of State Highway and Transportation Officials.-First Published in 1972 with the latest revision on 1993-It meets most of the demands placed on flexible pavements design procedure10

Traditional aashto flexible-pavement design procedure

SERVICEABILITY CONCEPT

For engineers, pavement failure occurred whenever cracking,rutting,or other surface distresses became visible.

For motoring public, pavement failure occurs when there is poor ride quality.

THE PAVEMENT SERVICEABILTY-PERFORMANCE CONCEPT-Developed by Carey and Irick-Developed to Handle both of pavement failure concepts11

Traditional aashto flexible-pavement design procedure

Present Serviceabilty index12

Traditional aashto flexible-pavement design procedure

Present Serviceability Index-It is usually done by a panel of raters who drive over the pavement section and rate the pavement performance on a scale of 1 to 5.-The usual initial PSI rating of a new pavement is 4.2 to 4.5

-The usual TSI rating of Interstate highways is 2.5 to 3.0,whereas local roads have a TSI rating of 2.013