Effect of pre-setting pressure applied flexure strength and fracture toughness of new SIFCON + RPC composite during setting phase

• We produced a new composite using SIFCON and RPC.
• We examine the effect of pre-setting pressure on SIFCON + RPC.
• We apply a specified beam mould and six different pre-setting pressures.
• We obtain the maximum flexure strength of 69.70 MPa under 15 MPa pre-setting pressure.
• Fracture toughness was increased by 32.03% with 12 MPa pre-setting pressure.

Reactive powder concrete (RPC) and Slurry Infiltrated Fiber Concrete (SIFCON) are steel fiber-reinforced cement composites which have superior mechanical properties such as compressive, tensile, shear and flexural strength with extraordinary toughness values. Manufacturing of a new composite material was intended by using superior performance of SIFCON in terms of flexural strength as well as superior performance of RPC in terms of compressive strength. For this reason, fresh SIFCON was filled into the bottom portion of mold by means of specially-designed molds and pre-setting pressure was applied by filling reactive powder concrete on it. For RPC and SIFCON in mold, pre-setting pressure was applied in six different pressures (0, 3, 6, 9, 12, 15 MPa). Test results indicated that maximum flexure strength was obtained as 69.70 MPa under 15 MPa pre-setting pressure. According to control-without pressure, flexure strength was improved by 43.21% with 15 MPa pre-setting pressure. Also fracture toughness was increased about 32.03% with 12 MPa pre-setting pressure. Prefabricated structural elements can be produced with the composite material, which is built via SIFCON + RPC composite, without needing a steel reinforcement.