Analysis on Criterion for Void Identifying under Cement Concrete Pavement Corner

Abstract

Based on deflections from theoretical analysis and falling weight deflectometer (FWD) at the slab center and corner, a method was established for the estimation of void size at the slab corner. Also, by modifying joint load-transfer capacity based on the theoretical slab corner deflection in infinite site slab under even supporting conditions, the theoretical slab corner deflection was calculated, and compared with FWD testing data to estimate the void conditions beneath the slab corner. A concept of void index was developed, which is defined as the ratio of deflections of testing in slab corner under FWD load against theoretical deflections. Through analyzing the relations between void index and other factors such as void size, slab modulus, slab thickness and foundation reaction modulus, the regression formula between void index and void size was established for the estimation of void size. The results of void identification using the method proposed in this study with the data from the test section at the Hunan Leiyi Expressway compare reasonably well with the actual condition, which proves the reasonableness and viability of the method proposed in this study.