矿物掺合料对钢渣混凝土物理力学性能及抗冻性的试验研究

发布时间：2018-05-15 06:00

本文选题：矿物掺合料 + 钢渣　；参考：《新疆农业大学》2016年硕士论文

【摘要】：钢渣是一种工业废渣,它的产生带来了很多问题。本文主要研究了钢渣粉和激发剂对水泥胶砂的影响,钢渣粉、粉煤灰和矿渣粉作矿物掺合料对钢渣混凝土物理力学性能及抗冻性的影响以及标准条件和自然条件养护方式对钢渣混凝土力学性能的影响。并借助扫描电镜、能谱观测分析钢渣混凝土内部的微观结构和水化产物。通过试验得到以下结论:(1)将不同掺量的钢渣粉分别掺入到水泥胶砂中,试验结果表明,掺有钢渣粉的水泥胶砂流动度随着掺量的增加出现先增大后减小的规律,抗折、抗压强度则随着钢渣粉掺量的增加而呈现逐渐降低的趋势。对比研究了NaOH,Na2SO4,Na2Si O3对钢渣粉的激发效果,结果发现Na2SO4的激发效果最好,NaOH的次之,Na2SiO3的最差。(2)将钢渣作为骨料替换混凝土中30%的天然石和50%的天然砂时,对混凝土的力学性能具有一定的增强效果。把钢渣粉掺入到不同品种水泥钢渣混凝土中,替换其中的水泥,试验结果发现,普通硅酸盐水泥、高抗硫酸盐硅酸盐水泥、快硬硫铝酸盐水泥钢渣混凝土的钢渣粉最优掺量分别为20%、10%、10%以及合理掺量范围一般不应超过30%、30%、20%。钢渣粉、粉煤灰和矿渣粉单掺作混凝土的矿物掺合料时,钢渣粉、粉煤灰和矿渣粉对钢渣混凝土的最优掺量分别是20%、10%和30%。并发现了掺入矿渣粉的钢渣混凝土的强度最高,粉煤灰的强度次之,钢渣粉的强度最低。通过配合比试验,发现了钢渣粉、粉煤灰和矿渣粉复掺时的最优比例。钢渣粉与粉煤灰复掺,钢渣粉与矿渣粉复掺,粉煤灰与矿渣粉复掺时的最优掺量都是10%,三者复掺时的最优掺量是20%,复掺的效果比单掺好。(3)对比研究了自然条件和标准条件下养护的钢渣混凝土强度的差异,发现这两种钢渣混凝土的强度差值随着龄期的增长越来越大。对钢渣混凝土进行冻融循环试验,结果发现,单掺粉煤灰的钢渣混凝土的抗冻性最好,复掺掺合料的钢渣混凝土、单掺矿渣粉的钢渣混凝土和空白组的抗冻性次之,单掺钢渣粉的钢渣混凝土的抗冻性最差。
[Abstract]:Steel slag is a kind of industrial waste slag, which brings a lot of problems. This paper mainly studies the influence of steel slag powder and activator on cement mortar. The effects of fly ash and slag powder as mineral admixtures on the physical and mechanical properties and frost resistance of steel slag concrete and the effects of standard conditions and natural conditions on the mechanical properties of steel slag concrete. The microstructure and hydration products of steel slag concrete were observed and analyzed by scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS). The test results show that the fluidity of the cement sand with steel slag powder increases first and then decreases with the increase of the content of steel slag powder, and the results show that the fluidity of cement sand with steel slag powder increases first and then decreases with the increase of the content of steel slag powder. The compressive strength decreases gradually with the increase of steel slag powder content. The excitation effect of NaOHNa-Na2SO4- Na2SiO3 on steel slag powder is studied. The results show that Na2SO4 has the best excitation effect of NaOH, followed by Na2SiO3) when steel slag is used as aggregate to replace 30% natural stone and 50% natural sand in concrete. It has a certain enhancement effect on the mechanical properties of concrete. The steel slag powder is mixed into different kinds of cement steel slag concrete to replace the cement. The test results show that ordinary Portland cement, high sulfate resistant Portland cement, The optimum content of steel slag powder in the fast hardening sulphoaluminate cement steel slag concrete is 20% and 10% respectively and the reasonable range should not exceed 30% and 20% respectively. When steel slag powder, fly ash and slag powder are used as concrete admixture, the optimum content of steel slag powder and slag powder is 20% and 30% respectively. The strength of steel slag concrete mixed with slag powder is the highest, the strength of fly ash is the second, and the strength of steel slag powder is the lowest. The optimum proportion of steel slag powder, fly ash and slag powder was found by mixing test. Steel slag powder and fly ash, steel slag powder and slag powder, The optimum mixing amount of fly ash and slag powder is 10%, the optimum addition of fly ash and slag powder is 20%, and the effect of compound mixing is better than that of single mixing. The difference of strength of steel slag concrete cured under natural condition and standard condition is studied. It is found that the strength difference between the two kinds of steel slag concrete increases with the age. The freeze-thaw cycle test of steel slag concrete is carried out. The results show that the frost resistance of steel slag concrete with only fly ash is the best, that of steel slag concrete with admixture is the best, that of steel slag concrete with single slag powder is the second, and that of blank group is the second. The frost resistance of steel slag concrete with steel slag powder is the worst.
【学位授予单位】：新疆农业大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TU528

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