A REVIEW ON CRACK RELIEF LAYER IN AIRPORT RUNWAY

Abstract

This article reviews the behaviour and function of the crack relief layer (CRL) in a pavement. The significance and effectiveness of implementing CRL into pavement layers to prevent reflective cracking are also included. Over the years, crack in pavement has been a major problem that causes obstacle to transportation system which has cost multi-millions of dollars. This is especially true in airport runway business industry where the traffic flow of aircrafts cannot be easily diverted or disturbed as it involve many parties and would jeopardize public safety. The characteristic of the CRL will be thoroughly investigated to achieve it desirable functional capability to act as the crack relieving agent. CRL is a layer made out of hot mixed asphalt that to the strata of the pavement with thickness of 100 to 150mm on top of base layer and under surface course. The significant of this hot mixed asphalt layer is in its capability to reduce reflective cracks development by separating bound and unbound layer and acting as buffer zone between those layers. Thus the layer designed to be semi-unbound layer to efficiently in creating the buffer zone for the crack transfer from the bottom to the top of the pavement. The layer also acts as the reducer by allowing cracks to  develop on the layer thus the crack generate on top of the pavement surface would decrease in the process.