Determining fracture properties of reclaimed asphalt pavement-based cement mortar using semicircular bending test

摘要

While critical stress intensity factor (K_(Ic)~S) and critical crack tip opening displacement (CTOD_c) are conventionally tested using single edge notched beam (SEN(B)) specimens, the test method suffers some drawbacks. A new test to characterize the fracture properties of the two-parameter fracture model (TPFM) using semi-circular bending (SCB) specimens has recently been developed by the authors. In comparison with the SEN(B) specimens, the SCB specimens can be readily made in lab from the commonly used cylindrical specimens. The geometry is also more suitable for field applications due to the ease of extracting cylinder specimens from concrete structures. In this study, the fracture properties of the TPFM for a reclaimed asphalt pavement (RAP) based cement mortar and a plain mortar at different curing ages were characterized using the SCB fracture test. The test results show that the RAP-Mortar (cement mortar containing 100% RAP) has lower K_(Ic)~S than the CON-Mortar (cement mortar containing 100% natural sand). However, the reduction of K_(Ic)~S is less significant than that of the compressive strength or splitting tensile strength. On the other hand, the RAP-Mortar was found to have higher CTOD_c than the CON-Mortar. The increased CTOD_c indicates that cement mortar containing RAP could potentially have a higher capacity to sustain cracking.