Challenges in the Construction of Concrete Pavements: An Indian National Highway Construction Experience

Abstract

The construction of cement concrete pavement is a very complex and sensitive process with many factors influencing the quality of concrete and the quality of finished pavement surface. In this paper, the authors presented the construction related issues faced during the construction of a national highway section in India. The major issues discussed are the edge collapse near horizontal curves in winter season in slip form paving method, uneven surface profile caused due to frequent starting and stopping of paver machine due to the difference in the mix delivery speed and the paver speed, the unexpected random cracking in a section of concrete pavement due to the delayed joint sawing, and the insertion marks of dowel bars in the concrete layer to name a few. The range of reasons that lead to theses challenging situations vary from the slope of super elevation to the frequency of vibration used for the dowel bar insertion. To further complicate the construction process, the variability in the quality of cement and super-plasticizer supplied to the construction site necessitate the frequent adjustments in the mix proportions to match the requirements of strength and workability. The selection of joint sawing time is equally difficult with many variables controlling the setting and hardening of concrete mix. The details of the highway section are: concrete layer thickness is 280 mm and concrete mix is of M40 grade, constructed over dry lean concrete sub-base of 150 mm thickness with a 125 microns' thick polythene separation sheet used for de-bonding.