铁尾矿微粉混凝土的力学性能分析  

Research on Mechanical Properties of Steel Slag Powder Road Concrete

作　　者：田尔布[1,2] 康海鑫 连跃宗 TIAN Er-bu;KANG Hai-xin;LIAN Yue-zong(Fujian Provincial Key Laboratory of Engineering Materials and Structure Reinforcement,Sanming University,Sanming 365004,China;School of Civil Engineering,Zhejiang University of Technology,Hangzhou 310014,China)

机构地区：[1]三明学院福建省工程材料与结构加固重点实验室,福建三明365004 [2]浙江工业大学土木学院,浙江杭州310014

出　　处：《三明学院学报》2021年第3期106-112,共7页Journal of Sanming University

基　　金：福建省科技厅社会发展引导性(重点)项目(2019Y0044);福建省教育厅科技项目(JT180505;B201816);福建省中青年教师教育科研项目(JAT190699);福建省工程材料与结构加固重点实验室开放基金(B17000109)。

摘　　要：铁尾矿是经过选矿之后形成的品位较低的以硅酸盐矿物为主的废渣,经过机械力粉磨的铁尾矿微粉具有一定活性。本研究将铁尾矿微粉取代部分水泥,进行水泥净浆流动性试验,水泥胶砂强度、混凝土力学性能试验。研究结果表明:铁尾矿微粉与高效减水剂兼容性良好,其掺量对净浆流动度有一定不利影响,当钢渣微粉掺量在30%范围内,减水剂掺量在1.2%时为最佳掺量;随着铁尾矿微粉掺量的增加,水泥砂浆抗折、抗压强度总体呈下降趋势,铁尾矿微粉参与二次水化作用,使胶砂抗折、抗压后期强度得到补偿性增长,7d活性指数达到矿物掺合料活性指数二级,28d活性指数则未达到二级;混凝土的抗折、抗压强度也随着铁尾矿微粉掺量的增加呈减小趋势,铁尾矿掺量超过10%时,混凝土抗折强度的下降速度大于抗压强度的下降速度,抗折强度与抗压强度比值呈现明显下降趋势。Iron tailings is a low-grade waste slag mainly composed of silicate minerals formed after beneficiation. The iron tailings fine powder has certain activity after mechanical grinding. In this study, iron tailings fine powder was used to replace part of the cement, and the cement paste fluidity test, cement mortar and concrete mechanical performance test were carried out. The research results show that the iron tailings fine powder has good compatibility with the superplasticizer, and its content has a certain adverse effect on the fluidity of the net slurry. When the content of steel slag powder is within 30%and the content of water reducer is 1.2%, it is the optimum mixing amount;with the increase of the amount of iron tailings fine powder, the flexural and compressive strength of cement mortars generally show a downward trend. The iron tailings fine powder participates in the secondary hydration, which makes the mortar resistant to bending and compression. The 7 d activity index reached the second level of the mineral admixture activity index, but the 28 d activity index did not reach the second level. The strength is increased compensatively;the flexural strength and compressive strength of concrete also show a decreasing trend with the increase of iron tailings fine powder content. When the iron tailings content exceeds 10%, the flexural strength of concrete decreases faster than the compressive strength. Decrease speed and the ratio of flexural strength to compressive strength shows an obvious downward trend.

关 键 词：铁尾矿微粉 混凝土 抗压强度 抗折强度 

分 类 号：TU528[建筑科学—建筑技术科学]