Experimental and Numerical Studies on the Effect of Built-In Gradient on Rigid Pavements

Abstract

AbstractRigid pavements are being widely adopted due to the various advantages they possess over flexible pavements. However it is seen that the built-in temperature gradient that gets captured in the concrete pavement during its construction can directly influence the stresses that develop in the pavement. This in turn may result in stress ranges that can adversely affect the long term performance of the pavement. The built-in temperature gradient can be seen to vary depending on the prevailing atmospheric conditions at the time of pavement construction for any given type of rigid pavement. As a result it becomes important to know what time or condition would be best for pavement construction for any given geographical region. This study focuses on identifying the built-in gradients developed in the pavement when the pavement is constructed at different times in the day. The study is conducted on scaled down specimens cast and exposed to climatic conditions similar to actual pavement conditions. The temperature gradients and the curling effects due to it were recorded. A comparison was done between the various readings taken at the different times of casting. Also fibre reinforced concrete was used for this study. A numerical analysis was then conducted for the given slab specimens under similar conditions using the finite element analysis software ANSYS. It can be seen that the experimental results can be validated using the numerical analysis. Results show that daytime construction such as late morning/afternoon/early evening pavement construction can result in negative built-in temperature gradients for the given climatic conditions in Kerala during summers.KeywordsPavementBuilt-in gradientCurlingFRC