Effect of slab-base interaction on measured concrete pavement responses

An experimental analysis of response data from actual aircraft passes at Denver International Airport was conducted to determine the effect of the slab-base interaction on concrete pavement responses. This analysis was divided into three parts: gap analysis from deflection data, interface analysis from paired strain data, and comparison between predicted and measured strains. The gap analysis showed that gaps exist between the slab and base, depending on the temperature differential and slab location. The gap analysis also indicated the existence of an effective built-in temperature difference. Despite the indication of gaps beneath the slab, the paired strain data analysis indicated contact friction or bonding action under wheel loading. The greatest contact friction occurred at the slab interior, followed by doweled transverse joints and transverse dummy joints, whereas an unexpected full-slip condition was found at tied longitudinal joints. The comparison between measured and predicted strain confirmed contact friction is developed under aircraft gear loading.