Effect of Ethylene-vinyl-acetate Copolymer on Mechanical Strength, Permeability Properties, and Hydrated Microstructure of Sprayed Concrete
ZENG Luping1, QIAO Min1, ZHAO Shuang1, WANG Wei1,*, CHEN Junsong1, ZHU Bosong1, RAN Qianping2, HONG Jinxiang1
1 Jiangsu Sobute New Materials Co., Ltd., Nanjing 211103, China 2 School of Materials Science and Engineering, Southeast University, Nanjing 211189, China
Abstract: The mechanical strength and permeability properties of sprayed concrete modified with ethylene-vinyl acetate copolymer ( EVA ) were evaluated, respectively in the form of redispersible polymer powder and polymer latex.And the physical film forming process and chemical action of EVA copolymer introuduced into accelerated cement paste were analyzed.The results show that particle adsorption, agglomeration and local film formation effect aroused by EVA copolymer were observed in accelerated cement paste, thus leading to the weakened formation of ettringite occurred in rapid hydration stage and retarding the early age hydration of alite minerals, especially when EVA copolymer was introduced in the form of polymer latex.Then the setting time of accelerated cement pastes is delayed significantly and the early strength is reduced with EVA copolymer.Compared to the pure sample, an increasing trend of circular bubbles with the diameter of over 130 μm was observed in hardened polymer modified sprayed concrete, thereby raising the hardened porosity and reducing the long-term strength and obvious air-entraining effect and improved spherical degree of hardened bubbles were observed with polymer powder used.At hydration time of 28 d, the continuous polymer film structure formed by EVA copolymer could be observed clearly in accelerated cement paste and fully dispersed and filled between the ettringite rods and hydration pores, thus enhancing water permeability resistance and flexural toughness of sprayed concrete, obviously.
1 Soh Y. Cement and Concrete Research, 2003, 33(10), 1497. 2 Jia H L, Gong H J, Guo M S, et al. Materials Reports, 2022, 36(20), 160 (in Chinese). 贾海林, 项海军, 郭明生, 等. 材料导报, 2022, 36(20), 160. 3 Al-zahrani M M, Maslehuddin M, Al-dulaijan S U, et al. Cement and Concrete Composite, 2003, 25(4), 527. 4 Wang P M, Zhao G R, Zhang G F. Journal of the Chinese Ceramic Society, 2018, 46(2), 256(in Chinese). 王培铭, 赵国荣, 张国防. 硅酸盐学报, 2018, 46(2), 256. 5 Chen D P, Liu F, Qi Y T. Materials Reports, 2015, 29(16), 115 (in Chinese). 陈东平, 刘芳, 齐艳涛. 材料导报, 2015, 29(16), 115. 6 Gretz M, Plank J. Cement and Concrete Research, 2011, 41(2), 184. 7 Betioli A M, Filho J H, Cincotto M A, et al. Construction and Building Materials, 2009, 23(11), 3332. 8 Smaniotto S, Neuner M, Dummer A, et al. Engineering Fracture Mechanics, 2022, 267, 108409. 9 Qiao Q, Chai H C, Zhang X T, et al. Bulletin of the Chinese Ceramic Society, 2022, 41(10), 3394 (in Chinese). 乔巧, 柴虎成, 张笑天, 等. 硅酸盐通报, 2022, 41(10), 3394. 10 Li X B, Qu G L, Yang C M, et al. Journal of Mining & Safety Engineering, 2019, 36(1), 95 (in Chinese). 李学彬, 曲广龙, 杨春满, 等. 采矿与安全工程学报, 2019, 36(1), 95. 11 Jiang P W, Zhang Z H, Wang H, et. al. Construction and Building Materials, 2022, 333, 127402. 12 Archibald J F, Degane D O, Tan M Q, et al. Mineral Engineering, 2002(5), 32 (in Chinese). 阿奇博尔德J F, 德加内 D O, 谭明乾, 等. 矿业工程, 2002(5), 32. 13 Romer M, Holzer L, Pfiffner M. Cement and Concrete Composite, 2003, 25(8), 1111. 14 Ning D P, Xu J Y, Wang Z H, et al. Journal of Air Force Engineering University, 2022, 23(2), 106 (in Chinese). 宁镱彭, 许金余, 王志航, 等. 空军工程大学学报(自然科学版), 2022, 23(2), 106. 15 Silva D A, Roman H R, Gleize P J P. Cement and Concrete Research, 2002, 32(9), 1383. 16 Wang P M, Zhao G R, Zhang G F. Journal of the Chinese Ceramic Society, 2014, 42(5), 653 (in Chinese). 王培铭, 赵国荣, 张国防. 硅酸盐学报, 2014, 42(5), 653. 17 Zhong S Y, Wang P M. Journal of Building Materials, 2004(2), 168 (in Chinese). 钟世云, 王培铭. 建筑材料学报, 2004(2), 168. 18 Leung CKY, Lai R, Lee AYF. Cement and Concrete Research, 2005, 35(4), 788. 19 GB/T 35159-2017 喷射混凝土用速凝剂[S] (in Chinese). GB/T 35159-2017 Flash setting admixtures for shotcrete[S]. 20 Wang R, Wang P M, Yao L J. Construction and Building Materials, 2012, 27(1), 259. 21 Zeng L P, Qiao M, Wang W, et al. Journal of Building Materials, 2021, 24(1), 31 (in Chinese). 曾鲁平, 乔敏, 王伟, 等. 建筑材料学报, 2021, 24(1), 31. 22 Ma H Y, Tian Y, Li Z J. Journal of Materials in Civil Engineering, 2011 23(10), 1412. 23 Zeng L P, Zhao S, Wang W, et al. Journal of the Chinese Ceramic Society, 2020, 48(11), 1781 (in Chinese). 曾鲁平, 赵爽, 王伟, 等. 硅酸盐学报, 2020, 48(11), 1781. 24 Silva D A, John V M, Ribeiro J L D, et al. Cement and Concrete Research, 2001, 31(8), 1177. 25 Wang P M, Zhao G R, Zhang G F. X-ray CT comparsion on pore structures in cement mortar modified by different redispersible polymer powders. 7th National Conference on Commercial Mortar, Beijing, 2017, pp.132 (in Chinese). 王培铭, 赵国荣, 张国防. 基于X-CT法不同可再分散乳胶粉改性砂浆孔结构的对比. 第七届全国商品砂浆学术交流会论文集. 北京, 中国建材工业出版社, 2017, pp.132. 26 Talukdar S, Heere R. Case Studies in Construction Materials, 2019, 11(1), 1. 27 Betioli A M, Gleize P J P, John V M, et al. Cement and Concrete Composite, 2012, 34(2), 255. 28 Zhang J L, Yin G Y, Ni C B, et. al. China Concrete and Cement Products, 2023(7), 57 (in Chinese). 张金林, 尹谷雨, 倪常彪, 等. 混凝土与水泥制品, 2023(7), 57. 29 Yao J L, Hu H M, Han F. Science Technology and Engineering, 2023, 23(27), 11816 (in Chinese). 姚江龙, 扈惠敏, 韩风. 科学技术与工程, 2023, 23(27), 11816. 30 Trussell N, Nordtug P, Asadi I, et al. Construction and Building Materials, 2023, 400, 132423. 31 Salvador R P, Cavalaro SHP, Cincotto M A, et al. Cement and Concrete Research, 2016, 89(1), 230. 32 Salvador R P, Cavalaro SHP, Segura I, et al. Construction and Building Materials, 2016, 111, 389. 33 Afridi M U K, Chaudhary Z U, Ohama Y, et al. Cement and Concrete Research, 1995, 25(2), 271. 34 Peng Y, Zhao G R, Wang P M. Journal of Chinese Electron Microscopy Society, 2016, 35(3), 240 (in Chinese). 彭宇, 赵国荣, 王培铭. 电子显微学报, 2016, 35(3), 240.