减缩型聚羧酸减水剂提高混凝土早期抗裂性的作用研究

硅酸盐通报 ›› 2021, Vol. 40 ›› Issue (10): 3359-3365.

减缩型聚羧酸减水剂提高混凝土早期抗裂性的作用研究

张建^1,2, 毛倩瑾^1,2, 王子明^1,2, 黄丽娜^1,2, 崔素萍^1,2

1.北京工业大学材料与制造学部,北京 100124;
2.北京工业大学新型功能材料教育部重点实验室,北京 100124

收稿日期:2021-04-09 修回日期:2021-04-25 出版日期:2021-10-15 发布日期:2021-11-11
通讯作者: 毛倩瑾,博士,副教授。E-mail:maoqj@bjut.edu.cn
作者简介:张建(1996—),男,硕士研究生。主要从事建筑材料的研究。E-mail:1164657580@qq.com
基金资助:
国家重点研发计划(2017YFB0310002)

Improving Early Crack Resistance of Concrete by Shrinkage-Reducing Polycarboxylate Superplasticizer

ZHANG Jian^1,2, MAO Qianjin^1,2, WANG Ziming^1,2, HUANG Lina^1,2, CUI Suping^1,2

1. Faculty of Materials and Manufacturing, Beijing University of Technology, Beijing 100124, China;
2. Key Laboratory ofAdvanced Functional Materials, Ministry of Education, Beijing University of Technology, Beijing 100124, China

Received:2021-04-09 Revised:2021-04-25 Online:2021-10-15 Published:2021-11-11

摘要/Abstract

摘要： 减缩型聚羧酸减水剂(SRPC)是一类兼具减缩与减水双重作用的新型混凝土外加剂,它对混凝土早期抗裂性的作用将影响其在工程中的应用。本文利用平板抗裂试验对比测试了掺SRPC、聚羧酸减水剂(PCE)及小分子减缩剂(SRA)的混凝土早期抗裂性,并通过对表面张力、收缩率、孔结构、水化热等参数的分析,讨论了SRPC影响混凝土抗裂性的作用机理。试验结果表明,尽管SRPC在掺量0.15%(质量分数)下的减缩效果弱于掺量1.5%(质量分数)的SRA,但SRPC表现出更佳的早期抗裂性能。机理分析表明,SRPC除了与SRA都是通过降低孔溶液表面张力及改变毛细孔结构从而减少混凝土的收缩外,还通过延缓水泥水化速率、降低早期水化放热量、抑制混凝土中水分蒸发等作用,改善混凝土的早期抗裂性。

关键词: 混凝土, 聚羧酸减水剂, 早期抗裂性能, 减缩, 水泥水化, 作用机理

Abstract: Shrinkage-reducing polycarboxylate superplasticizer (SRPC) is a new type of concrete admixture with both shrinkage-reducing and water-reducing effects.Its early crack resistance to concrete will affect its application in engineering. In this paper, the effect of SRPC on the early crack resistance of concrete was investigated and compared with polycarboxylate superplasticizer (PCE) and shrinkage reducing agent of low molecular weight (SRA) by using a flat crack resistance tester. Moreover, surface tension of solution, shrinkage of concrete, pore structure of cement slurry, and cement hydration heat were analyzed to discuss the anti-cracking mechanism of SRPC. Experimental results show that SRPC improved the early crack resistance of concrete. When 0.15% (mass fraction) SRPC and 1.5% (mass fraction) SRA are added to the concrete, although the former’s shrinkage effect is not as good as SRA, SRPC still show better early crack resistance. Compared with PCE, the cracked areas of SRPC and SRA are reduced by 39.33% and 21.34%, respectively. Mechanism analysis show that SRPC reduce the shrinkage of concrete by reducing the surface tension of the pore solution and changing the pore structure, which is similar to SRA. Furthermore, compared with SRA, SRPC also delay the rate of cement hydration, reduce the heat of early hydration, inhibit the evaporation of water inside the concrete, thereby improving the early crack resistance of concrete.

Key words: concrete, polycarboxylate superplasticizer, early crack resistance, shrinkage reduction, cement hydration, mechanism of action

中图分类号:

TQ172.1

张建, 毛倩瑾, 王子明, 黄丽娜, 崔素萍. 减缩型聚羧酸减水剂提高混凝土早期抗裂性的作用研究[J]. 硅酸盐通报, 2021, 40(10): 3359-3365.

ZHANG Jian, MAO Qianjin, WANG Ziming, HUANG Lina, CUI Suping. Improving Early Crack Resistance of Concrete by Shrinkage-Reducing Polycarboxylate Superplasticizer[J]. BULLETIN OF THE CHINESE CERAMIC SOCIETY, 2021, 40(10): 3359-3365.

参考文献

[1] 王子明,李慧群.聚羧酸系减水剂研究与应用新进展[J].混凝土世界,2012(8):50-56.
WANG Z M, LI H Q. New progress in the research and application of polycarboxylate water-reducing agents[J]. China Concrete, 2012(8): 50-56 (in Chinese).
[2] ZHANG Y R, KONG X M, GAO L, et al. Rheological behaviors of fresh cement pastes with polycarboxylate superplasticizer[J]. Journal of Wuhan University of Technology-Mater Sci Ed, 2016, 31(2): 286-299.
[3] HUANG H L, QIAN C X, ZHAO F, et al. Improvement on microstructure of concrete by polycarboxylate superplasticizer (PCE) and its influence on durability of concrete[J]. Construction and Building Materials, 2016, 110: 293-299.
[4] ZHANG Y R, KONG X M. Correlations of the dispersing capability of NSF and PCE types of superplasticizer and their impacts on cement hydration with the adsorption in fresh cement pastes[J]. Cement and Concrete Research, 2015, 69: 1-9.
[5] 钱晓倩,詹树林,方明晖,等.减水剂对混凝土收缩和裂缝的负影响[J].铁道科学与工程学报,2004,1(2):19-25.
QIAN X Q, ZHAN S L, FANG M H, et al. Negative influence of superplasticisers on shrinkage and cracking of concrete[J]. Journal of Railway Science and Engineering, 2004, 1(2): 19-25 (in Chinese).
[6] 谢韬,钱晓倩,胡超凡,等.减水剂掺量对混凝土早期收缩的影响及调控机制研究[J].混凝土,2020(8):15-18.
XIE T, QIAN X Q, HU C F, et al. Influence of superplasticiser on early shrinkage of concrete and its regulation mechanism[J]. Concrete, 2020(8): 15-18 (in Chinese).
[7] 周乐,张欣,关乾坤.聚羧酸减水剂在绿色混凝土中的力学性能[J].沈阳大学学报(自然科学版),2020,32(6):516-522.
ZHOU L, ZHANG X, GUAN Q K. Mechanical properties of polycarboxylate superplasticizer in green concrete[J]. Journal of Shenyang University (Natural Science), 2020, 32(6): 516-522 (in Chinese).
[8] 王子明,路芳.减缩型聚羧酸系高性能减水剂的现状与发展前景[N].中国建材报,2014-09-22(005).
WANG Z M, LU F. Current status and development prospects of shrinkage-reduced polycarboxylic acid-based high-performance water-reducing agents[N]. China Building Materials News, 2014-09-22(005) (in Chinese).
[9] 方绪顺,徐小平,陈国新,等.减缩型聚羧酸系减水剂的合成及性能研究[J].长江科学院院报,2015,32(12):134-138.
FANG X S, XU X P, CHEN G X, et al. Synthesis and performance of shrinkage-reducing polycarboxylate superplasticizer[J]. Journal of Yangtze River Scientific Research Institute, 2015, 32(12): 134-138 (in Chinese).
[10] 路芳,熊卫锋.减缩型聚羧酸减水剂对水泥基材料收缩性能的影响[J].混凝土,2014(5):91-92+96.
LU F, XIONG W F. Effect of shrinkage-reducing polycarboxylate superplasticizer on cement-based materials shrinkage performance[J]. Concrete, 2014(5): 91-92+96 (in Chinese).
[11] MARUYAMA I, TANIMURA M, MITANI Y, et al. Control of cracking in full-scaled columns made of ultra-high-strength concrete[J]. Materials and Structures, 2015, 48(6): 1627-1643.
[12] PARK S H, RYU G S, KOH K T, et al. Effect of shrinkage reducing agent on pullout resistance of high-strength steel fibers embedded in ultra-high-performance concrete[J]. Cement and Concrete Composites, 2014, 49: 59-69.
[13] LU Z C, KONG X M, LIU H, et al. Interaction of silylated superplasticizers with cementitious materials[J]. Journal of Applied Polymer Science, 2016, 133(43): 44161.
[14] WU L M, FARZADNIA N, SHI C J, et al. Autogenous shrinkage of high performance concrete: a review[J]. Construction and Building Materials, 2017, 149: 62-75.
[15] 顾越,冉千平,舒鑫,等.硅烷改性聚羧酸减水剂对水泥-硅灰浆体分散性能影响及机理[J].功能材料,2015,46(12):12087-12091.
GU Y, RAN Q P, SHU X, et al. Influence of silanized polycarboxylate superplastizers on fluidity of cement-silica fume pastes and its mechanism[J]. Journal of Functional Materials, 2015, 46(12): 12087-12091 (in Chinese).
[16] 沙胜男,史才军,向顺成,等.聚羧酸减水剂的合成技术研究进展[J].材料导报,2019,33(3):558-568.
SHA S N, SHI C J, XIANG S C, et al. The state-of-the-art synthesis techniques of polycarboxylate superplasticizer[J]. Materials Reports, 2019, 33(3): 558-568 (in Chinese).
[17] 李银斌,阮欣.机制砂混凝土抗裂性能试验研究[J].中外公路,2013,33(5):248-251.
LI Y B, RUAN X. Experimental study on the anti-cracking performance of machine-made sand concrete[J]. Journal of China & Foreign Highway, 2013, 33(5): 248-251 (in Chinese).
[18] 曹立学,郭君华,张磊,等.混凝土早期抗裂性能测试方法综述[J].硅酸盐通报,2020,39(10):3078-3089.
CAO L X, GUO J H, ZHANG L, et al. Review of test methods for early crack resistance of concrete[J]. Bulletin of the Chinese Ceramic Society, 2020, 39(10): 3078-3089 (in Chinese).
[19] 胡红梅,刘冬冬,余彬彬.外加剂对混凝土抗裂性能影响的试验研究[J].福建建材,2011(9):1-3+13.
HU H M, LIU D D, YU B B. Experimental study on the influence of admixtures on the anti-cracking performance of concrete[J]. Fujian Building Materials, 2011(9): 1-3+13 (in Chinese).
[20] 李悦,阮大威.不同外加剂对混凝土抗裂性能的影响[J].混凝土,2014(5):52-56.
LI Y, RUAN D W. Influence of different admixture on crack resistance of the concrete[J]. Concrete, 2014(5): 52-56 (in Chinese).
[21] MAO Q J, MA J F, WANG Z M, et al. Shrinkage reduction of cement-based materials containing polycarboxylate superplasticiser[J]. Magazine of Concrete Research, 2021, 73(5): 217-227.