掺合料种类对UHPC工作性能与力学性能的影响

The Effect of Supplementary Cementitious Materials on the Workability and Mechanical properties of Ultra-high Performance Concrete

以普通硅酸盐水泥、矿物掺合料、石英砂、微丝钢纤维为主要原材料制备UHPC,分析了不同水胶比下的硅灰、矿粉、粉煤灰对UHPC的砂浆拓展度和28d抗压强度影响。结果表明:硅灰A与粉煤灰有利于改善拌合物的砂浆拓展度,硅灰B与矿粉所制备的UHPC浆体的工作性能较差。同时,硅灰A有利于UHPC抗压强度提升,所制备UHPC的抗压强度高于硅灰B所制备的UHPC。硅灰种类相同时,矿粉和粉煤灰的抗压强度呈现不同规律,与硅灰A复配时,矿粉所制备的UHPC的28d抗压强度更高,与硅灰B复配时,粉煤灰所制备UHPC抗压强度更高。

UHPC is prepared with ordinary Portland cement,supplementary cementitious materials,quartz sand,and microfilament steel fibers as the main materials.The effect of silica fume types,slag and fly ash under different water-binder ratios on the slump flow and compressive strength of ultra-high performance concrete are analyzed.The results show that silica fume A and fly ash are beneficial to improve the mortar slump flow property,and the poor working performance of UHPC paste prepared by silica fume B and slag is relatively poor.Silica fume A is beneficial to the improvement of the compressive strength of UHPC,and the compressive strength is higher than that of the UHPC prepared by silica fume B.In the case of same silica same type,the compressive strength of slag and fly ash show different trends.The 28d compressive strength of UHPC prepared from slag is higher when mixed with silica fume A.When mixed with silica fume B,UHPC prepared by fly ash has higher compressive strength.