收尘石粉在混凝土中的应用研究

发布时间：2018-09-05 14:03

【摘要】：收尘石粉是在建筑石子生产过程中产生的,并通过收尘系统进行收集、存储的一种粉料。本研究就收尘石粉在混凝土应用中的力学性能及收尘石粉水泥的抗低温硫酸盐侵蚀性能进行研究,利用XRD和FTIR分析了收尘石粉水泥的低温硫酸盐侵蚀产物,为收尘石粉在混凝土中的应用提供技术依据。结果表明:随着收尘石粉掺量的增加,水泥胶砂强度逐渐降低;以收尘石粉等体积或等质量取代粉煤灰配制C30和C50混凝土,随着收尘石粉取代粉煤灰量的增加,混凝土1h的扩展度和坍落度损失变化不大,抗压强度先增大而后减小。收尘石粉水泥在低温下会遭受碳硫硅钙石型硫酸盐侵蚀(TSA),且收尘石粉掺量越大,养护龄期越长,TSA侵蚀破坏越严重。粉煤灰的掺入使收尘石粉水泥的强度有所降低,但能改善水泥抗低温硫酸盐侵蚀的能力,适宜的粉煤灰掺量为15%,收尘石粉掺量为15%。水胶比(w/c)越小,水泥石强度越高,抗低温硫酸盐侵蚀能力更强,水胶比0.3时,试件侵蚀270d时并未受到TSA侵蚀。防水剂的加入有利于改善收尘石粉水泥抗硫酸盐侵蚀性能,随着防水剂用量的增加,试样的抗压强度先增加后减小,适宜的掺量为1.8%。收尘石粉作为掺合料在混凝土工程中应用良好,成本较低。
[Abstract]:Dust collecting stone powder is a kind of powder produced in the process of building stone production and collected and stored by dust collecting system. In this paper, the mechanical properties of dust collecting stone powder in concrete application and the resistance to low temperature sulfate erosion of dust collecting stone powder cement are studied. The low temperature sulfate erosion products of dust collecting stone powder cement are analyzed by XRD and FTIR. It provides technical basis for the application of dust collecting stone powder in concrete. The results show that the strength of cement sand decreases gradually with the increase of the amount of dust collecting stone powder, and the C30 and C50 concrete is prepared by replacing fly ash with equal volume or equal mass of dust collecting stone powder, and the content of fly ash is replaced by dust collecting stone powder. The loss of expansion and slump of concrete for 1 h has little change, and the compressive strength first increases and then decreases. The dust collecting stone cement will suffer the (TSA), erosion at low temperature and the larger the amount of dust collecting stone powder, the longer the curing age is and the more serious the damage is. The addition of fly ash can reduce the strength of dust collecting stone cement, but it can improve the ability of cement to resist low temperature sulfate erosion. The suitable amount of fly ash and dust collection stone powder is 15 and 15 respectively. The smaller the water / binder ratio (w / c), the higher the strength of cement stone and the stronger the resistance to low temperature sulfate erosion. When the water / binder ratio is 0. 3, the specimen is not corroded by TSA at 270 d. The addition of water repellent helps to improve the sulfate resistance of dust collecting stone cement. With the increase of the amount of water repellent, the compressive strength of the sample increases first and then decreases, and the appropriate dosage is 1.8%. Dust collecting stone powder is used as admixture in concrete engineering and its cost is low.
【学位授予单位】：华北理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU528

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