HCSA膨胀剂掺量对水泥砂浆性能的影响研究

Study on the Influence of the Dosage of HCSA Expansion Agent on Cement Mortar Performance

浏览量:

关键词:

HCSA膨胀剂;工作性;力学性能;自收缩;微观结构

Key words:

HCSA expansion agent; Workability; Mechanical property; Self-Shrinkage; Microstructure

刊期:

2020年3期   No.287   P19-23

DOI:

10.19761/j.1000-4637.2020.03.019.05

文章编号:

基金项目:

国家自然科学基金(51774183);天地科技股份有限公司科技创新创业资金专项项目面上项目(2019-TD-MS00)。

作者:

杨 宁1,2 ;韩圣铭2

单位:

1.煤炭科学研究总院,北京 100013;2.北京中煤矿山工程有限公司,100013

摘要

摘   要:为探究HCSA膨胀剂掺量对水泥砂浆的影响,试验设计制作了6种HCSA膨胀剂掺量的水泥砂浆试块。对水泥砂浆的工作性、力学性能和收缩性能进行了测试,并通过扫描电子显微镜(SEM)观察其微观结构。研究结果表明:掺入膨胀剂能够减少水泥砂浆的初凝时间和流动度;掺入8%~10%的膨胀剂可以有效补偿水泥砂浆的自收缩;随膨胀剂掺量的增加,其抗压强度和抗折强度均呈先增加后减小的趋势;SEM结果表明,掺量4%的HCSA膨胀剂可以使水泥砂浆的微观结构得到优化。
 
Abstract: In order to explore the influence of HCSA expansion agent content on cement mortar performance, six kinds of cement mortar test blocks with HCSA expansion agent were designed and made. The workability, mechanical properties and shrinkage properties of cement mortar were tested, and its microstructure was observed by SEM. The results show that adding expansion agent can shorten the initial setting time and fluidity of cement mortar. In addition, the addition of 8%~10% expansion agent can effectively compensate the self-shrinkage of cement mortar. The compressive strength and bending strength of cement mortar increase first and then decrease with the increase of expansion agent. HCSA expansion agent with a content of about 4% can optimize the microstructure of cement mortar. 

结论

(1)加入HCSA膨胀剂,水泥砂浆的初凝时间减小,并且降低了水泥砂浆的流动性。
 
(2)水灰比0.5的水泥砂浆试块在HCSA膨胀剂掺量8%~10%时,能够解决水泥砂浆常温养护收缩大的问题,对水泥砂浆的自收缩具有较好的补偿收缩作用,并具有较好的膨胀稳定性。
 
(3)相比较空白组,适量的HCSA膨胀剂加入能够提高水泥砂浆的抗压和抗折强度。HCSA膨胀剂的掺量为4%时,水泥砂浆的强度具有最大值。
 
(4)由SEM图谱可知,适量膨胀剂的加入能够优化水泥砂浆的微观结构,使减少收缩的AFt晶体增多,浆体密实性更好,进而提高其力学性能。
 
(5)HCSA膨胀剂在合理掺量下,在提高强度的同时还可改善其微观结构,减小自收缩,使结构更加密实,根据此特点,可将HCSA膨胀剂推广应用于地下工程防水结构、煤矿立井井筒结构、水库大坝结构以及自密实混凝土结构等对质量要求较高的混凝土结构。

参考文献

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[2] BENTZ D P,JENSEN O M.Mitigation strategies for autogenous shrinkage cracking[J].Cement and Concrete Composites,2004,26(6):677-685.
 
[3] WANG A.DENG M,MO L.Effects of MgO-based expansive additive on compensating the shrinkage of cement paste under non-wet curing conditions[J].Cement and concrete composites,2012,34(3):377-383.
 
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引用本文

杨宁,韩圣铭.HCSA膨胀剂掺量对水泥砂浆性能的影响研究[J].混凝土与水泥制品,2020(3):19-23.
 
YANG N,HAN S M.Study on the Influence of the Dosage of HCSA Expansion Agent on Cement Mortar Performance[J].China Concrete and Cement Products,2020(3):19-23.

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