硅灰和减缩剂对混凝土自收缩和孔隙的影响

硅酸盐通报 ›› 2022, Vol. 41 ›› Issue (9): 3077-3083.

硅灰和减缩剂对混凝土自收缩和孔隙的影响

黄正峰, 欧忠文, 罗伟, 王飞, 王廷福

中国人民解放军陆军勤务学院,重庆 401311

收稿日期:2022-05-16 修回日期:2022-06-16 出版日期:2022-09-15 发布日期:2022-09-27
通讯作者: 欧忠文,博士,教授。E-mail:2111580448@qq.com
作者简介:黄正峰(1997—),男,硕士研究生。主要从事结构工程与军事工程抢修抢建研究。E-mail:11596846@qq.com
基金资助:
军队后勤科研计划项目(BLJ17J008);军委后保部科研项目(CLJ19J020);国家自然科学基金(11702324)

Effects of Silica Fume and Shrinkage Reducing Admixture on Autogenous Shrinkage and Porosity of Concrete

HUANG Zhengfeng, OU Zhongwen, LUO Wei, WANG Fei, WANG Tingfu

Army Logisticse College of PLA, Chongqing 401311, China

Received:2022-05-16 Revised:2022-06-16 Online:2022-09-15 Published:2022-09-27

摘要/Abstract

摘要： 硅灰和低水胶比会降低混凝土总孔隙率,但增加了混凝土自收缩,使其产生微裂纹。本文研究了掺入硅灰和减缩剂(SRA)对不同水胶比的混凝土自收缩和微观、宏观尺度孔径分布的影响。结果表明:掺入10%(体积分数)的硅灰会使混凝土自收缩增加27.3%~28.8%;而加入减缩剂使混凝土自收缩降低68.0%~85.1%,且对含有硅灰的混凝土样品降幅更大。此外,掺入硅灰和减缩剂可以使混凝土总孔隙率分别降低5.1%~6.0%和35.9%~39.7%,但硅灰会增大混凝土100 nm以下孔隙和100 μm以上孔隙的体积占比,而减缩剂对这两类孔隙的体积则会起相反作用。同时,自收缩与100 μm以上孔隙体积分数呈明显正相关关系。

关键词: 硅灰, 减缩剂, 水胶比, 自收缩, 孔径分布, 孔隙率

Abstract: Silica fume and low water-binder ratio will reduce the total porosity of concrete, but increase the autogenous shrinkage of concrete and lead to microcracks. In this paper, the effects of silica fume and shrinkage reducing admixture (SRA) on autogenous shrinkage and pore size distribution in micro and macro scale of concrete with different water-binder ratios were studied. The results show that the autogenous shrinkage of concrete increases by 27.3%~28.8% with the addition of 10% (volume fraction) of silica fume, while the autogenous shrinkage of concrete decreases by 68.0%~85.1% with the addition of SRA, and even more to the concrete samples containing silica fume. In addition, the addition of silica fume and SRA reduces the total porosity of concrete by 5.1%~6.0% and 35.9%~39.7%, respectively, but silica fume increases the proportion of pore volume below 100 nm and above 100 μm, while SRA has the opposite effect on the volume of these two types of pores. At the same time, there is a significant positive correlation between autogenous shrinkage and pore volume fraction above 100 μm.

Key words: silica fume, shrinkage reducing admixture, water-binder ratio, autogenous shrinkage, pore size distribution, porosity

中图分类号:

TU528.01

黄正峰, 欧忠文, 罗伟, 王飞, 王廷福. 硅灰和减缩剂对混凝土自收缩和孔隙的影响[J]. 硅酸盐通报, 2022, 41(9): 3077-3083.

HUANG Zhengfeng, OU Zhongwen, LUO Wei, WANG Fei, WANG Tingfu. Effects of Silica Fume and Shrinkage Reducing Admixture on Autogenous Shrinkage and Porosity of Concrete[J]. BULLETIN OF THE CHINESE CERAMIC SOCIETY, 2022, 41(9): 3077-3083.

参考文献

[1] 宁逢伟,蔡跃波,白银,等.膨胀剂和硅灰改善C50喷射混凝土抗渗性能的研究[J].硅酸盐通报,2019,38(10):3253-3259.
NING F W, CAI Y B, BAI Y, et al. Research on impermeability improvement of C50 shotcrete with expansive agent and silica fume[J]. Bulletin of the Chinese Ceramic Society, 2019, 38(10): 3253-3259 (in Chinese).
[2] 蒲心诚,刘芳,王冲,等.高强高性能混凝土中活性矿物掺料的火山灰反应及增强效应[C]//《硅酸盐学报》创刊50周年暨中国硅酸盐学会2007年学术年会论文摘要集,2007:73.
PU X C, LIU F, WANG C, et al. Pozzolanic reaction and strengthening effect of active mineral admixture in high strength and high performance concrete[C]//Journal of the Chinese Ceramic Society. Abstract Collection of Papers on the 50th Anniversary of the Founding of Silicate Journal and the 2007 Academic Annual Meeting of China Silicate Society, 2007: 73 (in Chinese).
[3] 王尚伟,朱海堂,王博,等.混凝土配合比优化设计的紧密堆积理论综述[J].材料导报,2021,35(3):3085-3091.
WANG S W, ZHU H T, WANG B, et al. Review of the packing theory for optimization design of concrete mix proportion[J]. Materials Reports, 2021, 35(3): 3085-3091 (in Chinese).
[4] GHAFARI E, GHAHARI S A, COSTA H, et al. Effect of supplementary cementitious materials on autogenous shrinkage of ultra-high performance concrete[J]. Construction and Building Materials, 2016, 127: 43-48.
[5] 张鹏,李绍纯,赵铁军,等.微裂缝钢混构件水分侵入的成像与定量表征[J].建筑材料学报,2015,18(3):438-443.
ZHANG P, LI S C, ZHAO T J, et al. Visualization and quantification of water penetration into micro-cracked steel reinforced concrete[J]. Journal of Building Materials, 2015, 18(3): 438-443 (in Chinese).
[6] 王鹏刚,付华,郭腾飞,等.蒸汽养护混凝土变形行为及开裂风险评估[J].材料导报,2022(24):1-14.
WANG P G, FU H, GUO T F, et al. Deformation behavior and cracking risk assessment of steam-cured concrete[J]. Material Reports, 2022(24): 1-14 (in Chinese).
[7] MEDDAH M, TAGNIT-HAMOU A. Effect of mineral admixtures on shrinkage measured on massive concrete elements[C]//International Conference, 2008.
[8] IGARASHI S I, WATANABE A, KAWAMURA M. Evaluation of capillary pore size characteristics in high-strength concrete at early ages[J]. Cement and Concrete Research, 2005, 35(3): 513-519.
[9] 高小建,巴恒静,杨英姿.矿物掺和料对混凝土早期开裂的影响[J].建筑科学与工程学报,2006,23(4):19-23.
GAO X J, BA H J, YANG Y Z. Effect of mineral admixture on early age cracking of concrete[J]. Journal of Architecture and Civil Engineering, 2006, 23(4): 19-23 (in Chinese).
[10] 杨全兵.高性能混凝土的自收缩机理研究[J].硅酸盐学报,2000,28(s1):72-75.
YANG Q B. Self-desiccation mechanisms of high-performance concrete[J]. Journal of the Chinese Ceramic Society, 2000, 28(s1): 72-75 (in Chinese).
[11] 徐彬彬,欧忠文,罗伟,等.饱水轻骨料和减缩剂对UHPC水化过程和自收缩的影响[J].材料导报,2020,34(22):22065-22069.
XU B B, OU Z W, LUO W, et al. Effect of saturated lightweight aggregate and SRA on the hydration process and autogenous shrinkage of UHPC[J]. Materials Reports, 2020, 34(22): 22065-22069 (in Chinese).
[12] 王俊颜,庄云芳,刘菲凡,等.减缩剂和PVA纤维对超轻水泥复合材料收缩开裂行为的影响[J].建筑材料学报,2021,24(6):1-11.
WANG J Y, ZHUANG Y F, LIU F F, et al. Effects of shrinkage reducing admixture and PVA fiber on shrinkage cracking behavior of ultra light cement composites[J]. Journal of Building Materials: 2021, 24(6): 1-11 (in Chinese).
[13] PIASTA W, ZARZYCKI B. The effect of cement paste volume and W/C ratio on shrinkage strain, water absorption and compressive strength of high performance concrete[J]. Construction and Building Materials, 2017, 140: 395-402.
[14] ZUO W Q, FENG P, ZHONG P H, et al. Effects of a novel polymer-type shrinkage-reducing admixture on early age microstructure evolution and transport properties of cement pastes[J]. Cement and Concrete Composites, 2019, 95: 33-41.
[15] BAROGHEL-BOUNY V, MOUNANGA P, KHELIDJ A, et al. Autogenous deformations of cement pastes[J]. Cement and Concrete Research, 2006, 36(1): 123-136.
[16] WINDSLOW D, DIAMOND S. A mercury porosimetry study of the evolution of porosity in Portland cement: technical publication[R]. Purdue University, 1969.
[17] RIBEIRO A B, GONÇALVES A, CARRAJOLA A. Effect of shrinkage reduction admixtures on the pore structure properties of mortars[J]. Materials and Structures, 2007, 39(2): 179-187.
[18] 梁柯鑫,王起才,张凯,等.低温(3 ℃)养护条件下不同水胶比对引气混凝土孔结构参数及抗渗性的影响[J].硅酸盐通报,2018,37(3):749-754.
LIANG K X, WANG Q C, ZHANG K, et al. Effects of different water-binder ratio on pore structure parameters and impermeability of air-entraining concrete at low temperature (3 ℃)[J]. Bulletin of the Chinese Ceramic Society, 2018, 37(3): 749-754 (in Chinese).
[19] ABYANEH S D, WONG H S, BUENFELD N R. Simulating the effect of microcracks on the diffusivity and permeability of concrete using a three-dimensional model[J]. Computational Materials Science, 2016, 119: 130-143.
[20] YANG Y, SATO R, KAWAI K J. Autogenous shrinkage of high-strength concrete containing silica fume under drying at early ages[J]. Cement and Concrete Research, 2005, 35(3): 449-456.
[21] LURA P. Autogenous deformation and internal curing of concrete[M]. Delft: Delft University Press, 2003.