[1] Qian Chunxiang, Lu Wangjie, He Zhihai, Fan Lingzhi, et al. Influence of superplasticizerson the early-age crack resistance of concrete [J]. Journal of Southeast University (English Edition), 2012, 28 (1): 41-45. [doi:10.3969/j.issn.1003-7985.2012.01.008]

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Influence of superplasticizerson the early-age crack resistance of concrete()

减水剂对混凝土早期抗裂性的影响

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Journal of Southeast University (English Edition)[ISSN:1003-7985/CN:32-1325/N]

Volumn:

28

Issue:

2012 1

Page:

41-45

Research Field:

Materials Sciences and Engineering

Publishing date:

2012-03-30

Info

Title:

Influence of superplasticizerson the early-age crack resistance of concrete

减水剂对混凝土早期抗裂性的影响

Author(s):

Qian Chunxiang¹;  Lu Wangjie¹;  He Zhihai¹;  Fan Lingzhi¹;  Qu Jun²;  Guo Jingqiang²

¹School of Materials Science and Engineering, Southeast University, Nanjing 211189, China
²Sika Technology AG, Baar 6341, Switzerland

钱春香¹;  陆旺杰¹;  何智海¹;  范凌志¹;  曲军²;  郭景强²

¹东南大学材料科学与工程学院, 南京211189; ²Sika Technology AG, Baar 6341, Switzerland

Keywords:

superplasticizer;  crack resistance;  slab test method;  temperature-stress test method

减水剂;  抗裂性;  平板法;  温度应力试验法

PACS:

TU528

DOI:

10.3969/j.issn.1003-7985.2012.01.008

Abstract:

In order to improve the early-age cracking resistance of concrete, different types of superplasticizers are used. Two types of polycarboxlic salt/acid superplasticizers and one retarding naphthalene superplasticizer are selected to investigate the influence of superplasticizers on the early-age cracking resistance of the concrete by using the slab test and the temperature-stress test. The results show that the polycarboxlic salt/acid superplasticizer cannot always improve the cracking resistance capacity of the concrete compared with the naphthalene superplasticizer, which is related to the chemical structure of the polycarboxlic salt/acid superplasticizer. High plastic tensile strength and dynamic elastic modulus at the early stage are beneficial to avoid cracking, and low hydration heat is also helpful. The evolutions of the drying shrinkage stress and the hydration heat temperature stress varying with time can be comprehensively evaluated by means of the slab test and the temperature stress test.

为了提高混凝土的早期抗裂性能, 使用了不同种类的减水剂.采用平板法和温度应力试验法, 研究了2种不同分子结构的聚羧酸减水剂和1种缓凝型萘系减水剂对混凝土早期抗裂性能的影响.结果表明, 与萘系相比, 聚羧酸减水剂并非一定能提高混凝土的早期抗裂性能, 这与聚羧酸的分子结构有关.早期塑性抗拉强度和动弹性模量较高, 将有利于抗裂, 在此前提下, 较低的水化热也有利于避免裂缝的产生.温度应力试验法与平板法结合可综合反映混凝土的干缩应力和水化热温度应力随时间的演化.

References:

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[2] Zhu Yijia. Effect mechanism research of water reducers on dry shrinkage of cement concrete[D]. Beijing:China Building Materials Academy, 2006:8-11.(in Chinese)
[3] Chen Bo, Cai Yuebo, Ding Jiantong. Comprehensive evaluation index of crack resistance of dam concrete [J]. Concrete, 2008(10):5-7.(in Chinese)
[4] Chen Yu, Zhang Qisen. Research status on the early-age crack resistance of cement concrete [J]. Journal of Building Materials, 2004, 7(4):411-417.(in Chinese)
[5] Li Hongjun, Tu Liuqing, Qin Minqiang, et al. Research on the early-age cracking susceptibility of Polypropylene fiber reinforced concrete [J]. The World of Building Materials, 2009, 1(30):41-44.(in Chinese)
[6] Gen Fei. Research of cement-based materials on plastic shrinkage and drying shrinkage [D].Nanjing: School of Materials Science and Engineering of Southeast University, 2004.(in Chinese)
[7] Liu Hongwei, Xie Li, Wu Shengxin. Tentative research on non-destructive detection of early-age elastic modulus of concrete [J]. Concrete, 2008(6):36-38.(in Chinese)
[8] Li Yue, Huo Kaicheng, Huang Jun. Experimental study on the early-age shrinkage and cracking susceptibility of concrete [J]. Journal of Huazhong University of Science and Technology:Urban Science Edition, 2007, 24(3):56-59.(in Chinese)
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Memo

Memo:

Biography: Qian Chunxiang(1966—), female, doctor, professor, cxqian@seu.edu.cn.
Foundation item: International Collaborative Research Project of Sika Technology AG of Switzerland, the Traffic Scientific Research Project in Jiangsu Province(No.2010Y01).
Citation: Qian Chunxiang, Lu Wangjie, He Zhihai, et al. Influence of superplasticizers on the early-age crack resistance of concrete[J].Journal of Southeast University(English Edition), 2012, 28(1):41-45.[doi:10.3969/j.issn.1003-7985.2012.01.008]

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