Experimental study on mechanical properties of a novel micro-steel fiber reinforced magnesium phosphate cement-based concrete

Magnesium phosphate cement(MPC)received increased attention in recent years,but MPC-based concrete is rarely reported.The micro-steel fibers(MSF)were added to MPC-based concrete to enhance its ductility due to the high brittleness in tensile and flexural strength properties of MPC.This paper investigates the effect of MSF volume fraction on the mechanical properties of a new pattern of MPC-based concrete.The temperature development curve,fluidity,cubic compressive strength,modulus of elastic,axial compressive strength,and four-point flexural strength were experimentally studied with 192 specimens,and a scanning electron microscopy(SEM)test was carried out after the specimens were failed.Based on the test results,the correlations between the cubic compressive strength and curing age,the axial and cubic compressive strength of MPC-based concrete were proposed.The results showed that with the increase of MSF volume fraction,the fluidity of fresh MPC-based concrete decreased gradually.MSF had no apparent influence on the compressive strength,while it enhanced the four-point flexural strength of MPC-based concrete.The four-point flexural strength of specimens with MSF volume fraction from 0.25%to 0.75%were 12.3%,21.1%,24.6%higher than that of the specimens without MSF,respectively.