低碳双掺钢渣混凝土的试验研究

发布时间：2018-02-28 10:43

本文关键词： 钢渣骨料钢渣粉混凝土力学性能耐久性能　出处：《西安建筑科技大学》2013年硕士论文　论文类型：学位论文

【摘要】：我国钢铁产业中钢渣废弃物的年排放量约为钢铁产量的15％～20％，大量废弃钢渣的排放引发了一系列环境保护问题，严重影响了环境和居民的正常生活；另外大量闲置场地的堆放占用，也带来一定的经济负担与资源损失。随着混凝土行业的复合化发展趋势与工业废弃物的高利用率需求，钢渣在混凝土中大掺量、高利用率及多样化的循环利用方式有待深入系统研究。本课题以钢渣的高附加值利用为研究目的，将粗破、筛分后的颗粒状钢渣作粗骨料，，磨细至一定细度的钢渣粉作掺合料，分别替代混凝土天然碎石骨料与水泥制备双掺钢渣混凝土。试验以钢渣混凝土体积稳定性良好为前提，开展双掺钢渣粗骨料/钢渣粉混凝土的宏观力学性能、耐久性能与长期性能试验研究；并利用扫描电镜、XRD衍射、显微硬度等微观测试手段，对不同骨料-水泥石界面与复合胶凝体系组成的微观结构进行了分析。试验结果表明：以钢渣粗骨料25%替代天然碎石为基础，钢渣粉30%/40%替代水泥作掺合料，双掺钢渣混凝土体积稳定性合格，力学性能、耐久性能满足试验设计指标；其中，25%钢渣骨料、30%钢渣粉试样组能够显著改善混凝土抗压、抗碳化、抗硫酸盐侵蚀等性能；值得重点关注的是，在双掺25%钢渣骨料与30%钢渣粉基础上复掺20%矿渣粉，混凝土的力学性能、耐久性能均表现最佳，钢渣粗骨料与废渣掺合料替代量分别达到25%、50%，实现了大掺量钢渣混凝土的研究目标。混凝土微观结构试验表明：钢渣骨料与水泥石的界面结构完整致密，显微硬度值高于天然碎石与水泥石界面区；复合胶凝体系水化程度较高、胶凝材料水化充分，该微观特性为双掺钢渣混凝土优良的宏观性能表现提供了理论依据。
[Abstract]:The annual discharge of steel slag waste in China's iron and steel industry is about 15% of the iron and steel output. The discharge of a large number of discarded steel slag has caused a series of environmental protection problems, which have seriously affected the environment and the normal life of the residents. In addition, a large number of idle sites have been stacked and occupied. It also brings some economic burden and resource loss. With the development trend of concrete industry and the demand of high utilization ratio of industrial waste, steel slag is heavily added in concrete. The high utilization rate and diversification of recycling methods need to be deeply and systematically studied. The purpose of this project is to use the high added value of steel slag as the research object. The granular steel slag after coarse breaking and sieving is used as coarse aggregate, and the steel slag powder with a certain fineness is used as admixture. Instead of natural crushed stone aggregate and cement, double-mixed steel slag concrete was prepared. On the premise of good volume stability of steel slag concrete, the macro mechanical properties, durability and long term performance of steel slag coarse aggregate / steel slag powder concrete were studied. The microstructure of different aggregate-cement stone interface and composite cementing system was analyzed by means of microhardness and microhardness. The test results show that the volume stability, mechanical properties and durability of steel slag concrete can meet the test design index with steel slag coarse aggregate 25% instead of natural crushed stone and steel slag powder 30% / 40% instead of cement as admixture. Among them, 25% steel slag aggregate and 30% steel slag powder sample group can significantly improve the compressive resistance, carbonation resistance and sulfate corrosion resistance of concrete, and the emphasis should be paid to the addition of 20% slag powder on the basis of 25% steel slag aggregate and 30% steel slag powder. The mechanical properties and durability of concrete are the best. The substitution quantity of steel slag coarse aggregate and waste slag admixture is 25 / 50 respectively, which realizes the research goal of large amount of steel slag concrete. The microstructure test of concrete shows that the interface structure of steel slag aggregate and cement stone is complete and compact, the microhardness value is higher than that of natural crushed stone and cement stone interface, the hydration degree of composite cementing system is higher, and the hydration of cementing material is sufficient. This microscopic property provides a theoretical basis for the excellent macroscopic performance of double-mixed steel slag concrete.
【学位授予单位】：西安建筑科技大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU528

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