摘要
Ecological reactive powder concrete (ECO-RPC) with small sized and differentvolume fraction steel fibers was prepared by substitution of ultra-fine industrial waste powder for50% to 60% cement by weight and replacement of ground fine quartz sand with natural fine aggregate.The effect of steel fiber volume fraction and curing ages on the static mechanical behaviour ofECO-RPC was studied. Using the split Hopkinson pressure bar technique, the dynamic mechanicalbehaviour of ECO-RPC was investigated under different strain rates. The results show that the staticmechanical behaviour of ECO-RPC increases with the increase of steel fiber volume fraction andcuring ages. The type of ECO-RPC with the substitution of 25% ultra-fine slag, 25% ultra-fine flyash and 10% silica fume is better than the others with compressive strength, flexural strength, andfracture energy more than 200 MPa, 60 MPa and 30 kJ/m^2, respectively. ECO-RPC has excellent strainrate stiffening effects under dynamic load. Its peak stress, peak strain and the area understrain-stress curve increase with the increase of strain rate. Its fracture pattern changes frombrittleness to toughness under high strain rates.
以50% ~60%的超细工业废渣取代水泥,用天然黄砂取代磨细石英砂,采用超细工业废渣多元复合技术,制备出生态型活性粉末混凝土(ECO RPC).研究了不同纤维掺量和不同养护龄期对ECO RPC静态力学性能的影响.采用霍普金森杆方法研究了高速冲击下应变速率对ECO RPC动态力学性能的影响.结果表明,随着纤维掺量和养护龄期的增加,ECO RPC各项静态力学性能不断提高.通过超细粉煤灰(25% )、超细矿粉(25% )和硅灰(10% )三掺制备的ECO RPC性能最佳,其抗压强度、抗折强度和断裂能分别达到200MPa, 60MPa和30kJ/m2 以上.ECO RPC具有明显的应变率强化效应,随着应变率的提高,峰值应力及峰值应变显著增长,应力应变曲线所包围的面积不断增大,破坏特征从脆性转变为韧性.
基金
TheNationalNaturalScienceFoundationofChina(No. 59938170)
