Three-point bending beams of cement paste and mortar with different sizes and strengths were tested. A complete load versus crack mouth opening displacement (P-CMOD) curve was directly obtained, and double-K fracture parameters could subsequently be determined. An apparent stable crack…
Three-point bending beams of cement paste and mortar with different sizes and strengths were tested. A complete load versus crack mouth opening displacement (P-CMOD) curve was directly obtained, and double-K fracture parameters could subsequently be determined. An apparent stable crack propagation preceding unstable failure was observed in cement paste, but this stable stage shortens with the increases in the compressive strength and the size lessening, furthermore the influence of specimen size on the stage was more obvious than that of strength. The experimental results show that resistance to crack propagation in ma- trix is enhanced due to aggregate in the matrix, though the grain size used was very small. The double-K frac- ture parametersKiniandKunof cement paste are size-independent. For cement paste and mortar, due to the in- Ic Ic un fluence of shrinkage crack, the divergence of the unstable fracture toughnessKIc is more evident than initial fracture toughnessKini.