Tensile behavior of restrained expansive mortar and concrete

Effect of restraint on the tensile behavior of expansive mortar was investigated by testing specimens with concentrically un-bonded restraint, chemically prestressed mortar (CPM), and chemically prestressed concrete (CPC). The deformation under flexural load is measured by a series of strain gages. In the test of specimens with un-bonded restraint, the restraining steel was removed and the expansion, chemical prestress, and rebound strain are measured before the flexural test. Tensile strength, cracking strain capacity as well as the plastic deformation was quantitatively investigated. The results show that the restrained expansive mortar has unique tensile properties, i.e., larger cracking strain capacity, non-linearity, and more plastic deformation. The effects of bonding between rebar and mortar, curvature, and the presence of coarse aggregate on the tensile properties of CPM and CPC were also experimentally investigated.