Surface Texture Measurements of Crack Surface to Establish Joint Shear Stiffness

Pavement design has evolved from a purely empirical approach to a more mechanistic-based approach. One of the primary distresses considered when designing jointed plain concrete pavements is faulting. The development of faulting is largely a function of the load transfer efficiency at the joints. For undoweled joints, the load is primarily transferred through the aggregate interlock provided by the texture resulting from the meander in the transverse crack propagating off from the sawed joint. This paper shows how volumetric surface texture, a measurement of the surface texture at the crack face, can be used for this purpose. A method is presented for estimating the joint stiffness parameter, J_agg, required for the faulting prediction model incorporated into the AASHTOWare Pavement ME Design software based on the measured surface texture. This method allows the effects of aggregate size, type, and quantity to be captured and joint stiffness to be quantified when faulting is being predicted.