The crack sensitivity of jointed plain concrete pavement is investigated experimentally in the laboratory for a limited number (seven) of large-scale slabs and numerically as well using nonlinear fracture mechanics. The basis for modeling is the concrete crack-width relation and the elastic modulus. The stress-crack width relations for the concrete were obtained on the concretes tested in the laboratory. The slab dimensions in the experimental and numerical analysis were 1.8 m wide and 3.0 m long, and a full-depth cross section (250 mm) containing a full-width surface crack extending 20% to 25% of the slab thickness was used. The major findings are that the numerical analysis verifies that the results from laboratory testing resemble field fracture behavior. Further, irrespective of the aggregates used, a concrete pavement is highly crack sensitive, although the coarse aggregate can affect the sensitivity by approximately 30%. The experimental and numerical results showed that a crack-to-slab-thickness ratio of 20% to 25% reduced the in-plane tensile capacity of the cracked section by 60% to 75% depending on the concrete used.
Abstract