INVESTIGATION ON THE CAUSES OF PAVEMENT FAILURE

1.1 INTRODUCTION

The site under investigation is Hillview of ESBS Road Enugu.

Along the site failures are observed especially depress on pavement and lost of pavement totally which are caused by excessive moisture in the sub – grade.

The aim of the investigation is to know  the extent of the failure on the flexible pavement and the nature of the failure.

The aim is also to give recommendation on how to improve the pavement which has occurred at the site under investigation.

1.2 LITERATURE REVIEW

The uses and application of modern technologies and new concepts have been deviced to tackle problem of pavement failure by many organized bodies.

1.3 DEFINITION OF PAVEMENT

a pavement can be defined as the hard crust of the road structure placed above the soil formation or sub-grade.

1.4 FUNCTIONS

The function of pavement is to transmit acceptable pressure to the bearing subgrade through sub base soil which must be less than the bearing capacity of the soil sub-grade.

1.5 TYPES OF ROAD PAVEMENT

There are two main types of pavement

(i)  Flexible Pavement

(ii) Rigid Pavement

1.6 FLEXIBLE PAVEMENT

This consist of various lagers of high way building materials compacted so as to be void free and finished with elastic surface such as bitumen as asphalt maintain intimate constant and distributes inter lock, particle reaction and cohesiol per stability.

1.7  ADVANTAGES OF FLEXIBLE PAVEMENT

If good services are to be received from bituminous pavement it must be for its full life, retain the following qualities.

(i) Smooth riding or in skid surface

(ii) Tight, impermeable surface or porous surface

(iii) No cracking or fatigue failure

(iv) Resistance of weather

(v) Resistance of moisture

1.8 DISADVANTAGE OF FLEXIBLE PAVEMENT

If not properly constructed --- will be

(i) Poor weather resistance

(ii) Presence of cracking

(iii) High cost is incurred during construction

(iv) Fatigue failure will occur

1.9 RIGID PAVEMENT

This type of pavement is made up of reinforcement or non – reinforcement concrete slab. It consist of two layers the cement slab and the snobs of granular material or stabilized soil.

These two large are sprees I n separate construction operation.

1.10 ADVANTAGE OF RIGID PAVEMENT

This types of pavement has long life, when properly design constructed.

It has low maintenance cost

The reinforcement made it not flexible

1.11 DISADVANTAGE OF RIGID PAVEMENT

(i) Trans-cracking of concrete paving slab under combined flexural and direct tensile stress is inevitable.

(ii) Longitudinal crack slab more than one lone wide is also inevitable