Modelling Joint Deterioration in Roller Compacted Concrete Pavement

Joints in Roller Compacted Concrete (RCC) pavements are used to distribute traffic loading between adjacent slabs by friction. The Load Transfer Stiffness (LTS) of the joints has critical effects on RCC pavement performance near the joints. Research has shown that LTS can deteriorate over time due to traffic loading or environmental conditions. This study investigates the deterioration of LTS of RCC pavement joints and its effect on the fatigue cracking performance near the joints. To achieve that, first, an innovative experimental programme was designed to measure LTS as a function of number of load repetition, joint width, and RCC mix properties using a cyclic shear test setup. Second, a mathematical model was derived to predict LTS deterioration in joints. This model was validated against the experimental data. Lastly, an RCC pavement design model was developed using the LTS deterioration model. To demonstrate the application of the developed solution, a hypothetical RCC pavement structure consisting of four slabs was considered. The analysis results show that LTS has inverse relationship and direct impact of fatigue life of RCC. In particular, the results demonstrate that fatigue damage over an analysis period of 20 years is negligible if LTS is assumed constant, which is unrealistic, but it can reach 40% if LTS deterioration is considered in the analysis. Accordingly, this study recommends considering the deterioration of RCC joint LTS when design that kind of pavement structures.