持续静力荷载作用下钢渣-沙漠砂混凝土的劣化机理  

Deterioration Mechanism of Steel Slag-Desert Sand Concrete under Continuous Static Load

作　　者：秦拥军[1] 龙镇吉 龚磊 黄东 田元 QIN Yongjun;LONG Zhenji;GONG Lei;HUANG Dong;TIAN Yuan(School of Civil Engineering and Architecture,Xinjiang University,Urumqi 830047,China)

机构地区：[1]新疆大学建筑工程学院,新疆乌鲁木齐830047

出　　处：《河南科技大学学报(自然科学版)》2025年第2期59-68,M0005,M0006,共12页Journal of Henan University of Science And Technology:Natural Science

基　　金：国家自然科学基金项目(52268046);新疆维吾尔自治区重点研发项目(2022B03036-1)。

摘　　要：通过正交试验,优选出满足C30强度等级的钢渣-沙漠砂混凝土配比,后续再对优选组和对照组混凝土试件各施加0.3倍和0.5倍的极限抗压强度,分别在30 d、60 d和90 d测量其损伤参数和微观结构。研究结果表明:新型沙漠砂混凝土最优水灰比为0.45,沙漠砂最优替换率为30%,粉煤灰最优替换率为20%,钢渣粉最优替换率为10%。持续的荷载作用会引起混凝土外表面剥落从而导致质量损失,质量损失率在60 d后趋于稳定。混凝土的相对动弹性模量随着加载时间的增加,先增大后降低。持续加载会导致混凝土内部孔隙的孔径逐步发育并增大。孔隙率随着施加荷载时间的增加呈现出先减后增的趋势。持续荷载对混凝土的物相组成及晶体结构基本无影响。Through orthogonal experiments,the optimal mix proportion of the steel slag-desert sand concrete that meets the C30 strength grade was selected.Subsequently,the concrete specimens of the selected group and the control group were subjected to 0.3 times and 0.5 times ultimate compressive strength respectively,and their damage parameters and microstructure were measured at 30 d,60 d and 90 d.The research results show that the optimal water-binder ratio of the new desert sand concrete is 0.45,the optimal substitution rate of desert sand is 30%,the optimal substitution rate of fly ash is 20%,and the optimal substitution rate of steel slag powder is 10%.Continuous loading will cause the outer surface of the concrete to peel off,resulting in mass loss,and the mass loss rate tends to be stable after 60 d.The relative dynamic elastic modulus of the concrete increases first and then decreases with the increase of loading time;continuous loading will cause the pore diameter of the internal pores of the concrete to gradually develop and increase;the porosity shows a trend of first decreasing and then increasing with the increase of loading time.The continuous loading has little effect on the phase composition and crystal structure of the concrete.

关 键 词：沙漠砂 钢渣 冶金固废 持续荷载 劣化机理 

分 类 号：TU528[建筑科学—建筑技术科学]