Improved estimates of temperature distributions for design of jointed plain concrete pavements in India and Nepal

Abstract

Local weather conditions give rise to temperature distributions within Jointed Plain Concrete Pavements (JPCPs). Previous research has demonstrated that these temperature distributions are non-linear, leading to the development of curling and eigenstresses. In India and Nepal, JPCPs are designed based on the IRC:58 and NCRDG standards, respectively, in which the two countries are divided into a small number of climatic zones that span large geographical areas. Within each zone, a single linear temperature difference is prescribed for design, while eigenstresses are not explicitly considered. This may lead to erroneous designs that overlook local climatic variations within each zone, potentially leading to over- or under-designed sections. In this study, two historical climate datasets – ASOS and ERA5 – were examined for predicting temperature distributions in 150–250 mm thick JPCPs. ASOS was found to contain a lot of missing data, which could not be cleaned and ERA5 was found to be more suitable. A pavement temperature prediction program, called ILLI-THERM, was then validated and used to develop temperature distributions for the sections across 24 locations. These distributions were then decomposed into linear temperature differences and eigenstresses. The results indicate that temperature differences exhibit a broad distribution, and eigenstress is significant in all cases. When comparing the 90th percentile distribution values with the codes of practice, it is found that the design standards tend to be overly conservative in most climate zones for both bottom-up and top-down cracking. This can lead to sections being over-designed, leading to increased costs and environmental impacts.