FAILURE OF ROAD PAVEMENT

INTRODUCTION

                      " ROAD   PAVEMENT "

•     “That with which anything is paved; a floor or  covering of solid material, laid so as to make  a hard  and convenient surface for travel; a paved road or sidewalk; a decorative interior floor of tiles collared bricks”

                  

1.1   General : - 

A number of portions of the National Highways by NHAI (National Highway Authority of
India) and Rural roads under PMGSY (Pradhan Mantri Gram Sadak Yojna - A special scheme to
connect the rural areas of India to all weather roads by Ministry of Rural Development) around
the country are being strengthened and simultaneously being widened. But with the passage
of time, the traffic intensity increased on these roads and the pavements started showing
distress in the form of minor cracks.

Some  sections  developed  cracks  after  being  overlaid  with  bituminous  surfacing.
However, the cracks on the bituminous surfacing included cracks, which appeared as reflective
cracks or in the form of raveling that requires frequent repair treatment. The rehabilitation of
cracked roads by simply overlaying with a layer of bitumen is rarely a durable solution. The
cracks gradually propagate through the new overlay.

It is a matter of fact that newly overlaid bituminous layer does not possess the inherent
property to prevent the propagation of cracks. The phenomenon referred to as reflective
cracking is prevalent over many countries around the world. With the current financial crunch
the departments involved in road construction are forced to use solutions with a balanced cost
benefit objective.

The formation of cracks in the top layer of a pavement causes numerous problems such
as discomfort to the users, reduction of safety, etc. In addition to the above, intrusion of water
causing reduction of the strength in lower layers as well as lowering of bearing capacity of sub
grade soil by pumping of soil particles through the cracks is also a major problem associated
with the pavements. This leads to the progressive degradation of the road pavement structure
in the  of the cracks (Sikdar, Jain, Bose and Kumar, 1999).

The origin of cracks differs by their shapes, configuration, and amplitude of loading,
movement of traffic and rate of deformation. A number of remedial measures have been
recommended in the past and are still in experimental stages.

Road transportation is an important element in the physical development of any society
as it controls the direction and extent of development (2003). Good roads promote the

economic growth of a nation by creating enabling environment for the movement of goods.

and services. Oil and gas products, solid minerals, raw and finished products are moved to
points of need via roads. A good network of roads will reduce haulage vehicle accidents
thereby minimizing human and material losses.

                                                               Road Pavement

An artificial surface lay over the ground to facilitate travel.  pavement’s ability to
support loads depends primarily upon the magnitude of the load, how often it is applied, the
supporting power of the soil underneath, and the type and thickness of the pavement
structure. Before the necessary thickness of a pavement can be calculated, the volume, type
and weight of the traffic (the traffic load) and the physical characteristics of the underlying soil
must be determined.

                                                                            OR

That with which anything is paved; a floor or covering of solid material, laid so as to make
a hard and convenient surface for travel; a paved road or sidewalk; a decorative interior floor
of tiles colored bricks .