Development of guidelines for low volume concrete road construction in Sri Lanka

Abstract

The purpose of the study was to develop guidelines for construction of low volume concrete roads in Sri Lanka. A survey was carried out to study current concrete road construction practices and knowledge of the contractors involved in concrete road construction. Survey results show that good practices have not been adopted in low volume road construction in Sri Lanka. The authors have introduced best practices which can be easily adopted by the local road construction industry. Incorrect joints construction was observed in concrete roads during the site visit and the Authors have introduced a new device for contraction joint construction. A modification to the available method was proposed to measure surface undulation on local concrete pavements and allowable undulation was determined through field investigation. A comparison of various kinds of concrete producing and curing methods and their performance were studied. The authors have evaluated the effectiveness of rebound hammer method which has been used for quality control by some consultants. Rebound hammer reading was compared with compressive strength which was found out from core cutter samples. Double beam vibrator with inbuilt camber was introduced to consolidate and form the camber of the surface layer. Check lists for subgrade /subbase, shoulder, formwork and concrete placing and finishing have been introduced to address weakness and enhance the quality of the pavement construction. Quality and Cost control techniques in the field of low volume concrete road construction in Sri Lanka are also described. Further, the proposed guideline describes the most appropriate methods for preparation of subgrade, subbase and shoulder, and mixing, placing and finishing of concrete.