Development of Cementitious Composites with Tensile Strain Capacity up to 10%

Abstract

Strain hardening cementitious composites (SHCC) are known for their high ductility under tension and bending. Reinforced with random distributed polymer fibers, the normal SHCC have the tensile strength ranging from 3 MPa to 7 MPa and the tensile capacity about 3%–6%. Nevertheless, such level of ductility is not sufficient to make the material free from steel reinforcement in case of constructing structure likely to be subjected to extreme conditions, such as earthquake. The present research aims to enhance the ductility of SHCC to a higher level, so that it may be used for construction without steel reinforcement. The motivation leads to the birth of ultra-high ductility cementitious composite (UHDCC). Three different mixture designs were adopted in the present study. The axial tensile tests indicated that all the tensile strain capacities of UHDCC exceeded 10% with the peak tensile strength varied between 5 MPa and 9 MPa. Moreover, the compressive tests showed that the compressive strength of UHDCC reached 25 MPa–45 MPa. When the compressive strength was not higher than 35 MPa, the cubic specimens exhibited exceeding compressive strain capacity. The compressive strain capacity is attributed to the high tensile capacity and the lateral confinement from the stiff platen of testing machine.