Mechanical properties and durability of ultra-high performance concrete containing coarse aggregate
Coarse aggregate was incorporated in UHPC to prepare ultra-high-performance concrete with coarse aggregate(UHPC-CA),and the effects of different volume fractions of coarse aggregate(0,15%,30%,40%)and steel fiber volume fractions(0.5%,1.0%,1.5%,2.0%)on the mechanical and durability properties of UHPC-CA were investigated through cube compressive strength test,splitting tensile strength test,freeze-thaw cycle test and sulfate corrosion resistance test.The results show that the cube compressive strength of UHPC-CA generally increases with the increase of steel fiber content,but some groups show a slight decrease when the steel fiber volume fraction reaches 2%.The compressive strength of UHPC-CA first increases and then decreases with the increase of coarse aggregate content.The splitting tensile strength of UHPC-CA increases with the increase of steel fiber content,and the maximum increase in splitting tensile strength is 86.9%when the steel fiber volume fraction reaches 2%,while the addition of coarse aggregate has a negative effect on splitting tensile strength.Regarding durability,the increase of steel fiber content improves the freeze-thaw and sulfate corrosion resistance of UHPC-CA,while the addition of coarse aggregate has a negative effect on its durability.