基于宏-细观尺度的钢渣混凝土力学性能研究

Research on Mechanical Properties of Steel Slag Concrete Based on Macro-meso Scale

为研究钢渣细骨料混凝土的力学性能,配制了钢渣替代率为0、10%、20%、30%的砂浆和混凝土,进行砂浆抗压强度、混凝土立方体抗压强度、劈裂抗拉强度、抗折强度试验。结果表明:粒化钢渣具有界面过渡区,可以减弱钢渣砂浆的抗压强度;钢渣具有一定的水化活性,可以提高砂浆的水灰比,进而提高砂浆的抗压强度;钢渣掺量为20%时,混凝土试件的立方体抗压强度、劈裂抗拉强度最大;钢渣掺量为30%时,混凝土试件的抗折强度最大。基于细观尺度,将钢渣混凝土看作由砂浆、粗骨料、钢渣颗粒、砂浆-粗骨料界面和砂浆-钢渣颗粒界面组成的五相复合材料。建立钢渣混凝土细观数值模型,模拟不同钢渣掺量的混凝土立方体抗压强度、抗折强度、荷载-挠度曲线。模拟结果与试验结果符合较好,验证了细观模型的正确性。

In order to study the mechanical properties of steel slag fine aggregate concrete,mortar and concrete with steel slag substitution rate of 0,10%,20%and 30%were prepared.The compressive strength of mortar,the compressive strength of concrete cube,the splitting tensile strength and flexural strength were tested.The results showed that the granulated steel slag had interface transition zone,which could weaken the compressive strength of steel slag mortar.Steel slag had a certain hydration activity,which could improve the water-cement ratio of mortar,and then improve the compressive strength of mortar.When the substitution rate of steel slag was 20%,the compressive strength and splitting tensile strength of concrete specimens were the largest.When the substitution rate of steel slag was 30%,the flexural strength of concrete specimen was the highest.Based on the meso scale,the steel slag concrete was regarded as a five-phase composite composed of mortar,coarse aggregate,steel slag particles,the interface of mortar and coarse aggregate,and the interface of mortar and steel slag particles.The meso numerical model of steel slag concrete was established to simulate the compressive strength,flexural strength and load-deflection curves of concrete cubes with different steel slag contents.The simulation results were in good agreement with the experimental results,which verified the correctness of the meso model.