1 College of Civil Engineering, Qingdao University of Technology, Qingdao 266033, China; 2 Guangdong Provincial Key Laboratory of Durability for Marine Civil Engineering, College of Civil Engineering, Shenzhen University, Shenzhen 518060, China
Abstract: The porous interfacial transition zone of the aggregate-cement slurry is an important reason for the difference between the properties of recycled aggregate and natural aggregate. The effect of microbial mineralization deposition on interfacial transition zone of recycled aggregate was studied. Cement paste was used to wrap recycled aggregate treated by different bacteria in different ways. After curing, the aggregate-cement interface transition zone was obtained by crushing. SEM was used to observe the changes in the microstructure of the interface transition zone. The elastic modulus and hardness of the interface transition zone were measured by nano indentation instrument. Combined with the compressive and flexural strength test results of reclaimed mortar blocks, the improvement effect of microbial mineralization deposition on interfacial transition zone of recycled aggregate was analyzed. The results showed that the recycled aggregate was treated with bacillus pseudoadamus and bacillus basophilus. The compressive and flexural strength of the recycled mortar prepared and the elastic modulus and hardness of the interfacial transition zone of recycled aggregate were significantly increased. The different mineralization capacity of the two strains leads to the difference of performance improvement effect.
1 Xiao J Z. Recycled concrete, China Architecture & Building Press, China, 2008 (in Chinese). 肖建庄.再生混凝土,中国建筑工业出版社,2008. 2 Liu X, Zhang X, Li W X. Architecture Technology, 2010, 41 (1), 63 (in Chinese). 刘昕, 张雄, 李雯霞. 建筑技术,2010, 41 (1),63. 3 Chen D Y, Yuan W, Liu H. New Building Materials, 2009 (2), 20 (in Chinese). 陈德玉, 袁伟, 刘欢.新型建筑材料, 2009 (2),20. 4 Xiao J, Li J, Zhu B, et al. Construction and Building Materials,2002,16 (3),187. 5 Tittelboom K V, Belie N D, Muynck W D, et al. Cement & Concrete Research, 2010, 40 (1),157. 6 Lee G C, Choi H B. Construction & Building Materials, 2013, 40 (40),455. 7 Zhang X T. Study on modified regenerative aggregate and its mechanism by microbial mineralization deposition. Master's Thesis, Qingdao University of Technology, China, 2016 (in Chinese). 张晓彤.微生物矿化沉积改性再生骨料及其机理研究. 硕士学位论文, 青岛理工大学, 2016. 8 Gao L X, Sun G W. Journal of the Chinese Ceramic Society, 2013 (5), 627 (in Chinese). 高礼雄, 孙国文. 硅酸盐学报, 2013 (5), 627. 9 Jonkers H M, Thijssen A, Muyzer G, et al. Ecological Engineering, 2010, 36 (2),230. 10 Cheng L, Qian C X, Wang R X, et al. Journal of the Chinese Ceramic Society, 2008 (S1),215 (in Chinese). 成亮, 钱春香, 王瑞兴, 等. 硅酸盐学报, 2008 (S1), 215. 11 Zhu Y G, Wu C R, Wu Y K. et al. Concrete, 2018 (6),88 (in Chinese). 朱亚光, 吴春然, 吴延凯, 等. 混凝土, 2018 (6), 88. 12 Zhu Y G, Wu Y K, Wu C R. et al. J. Concrete, 2017 (12), 93 (in Chinese). 朱亚光, 吴延凯, 吴春然, 等. 混凝土, 2017 (12),93. 13 Poon C S, Shui Z H, Lam L. Construction and Building Materials, 2004, 18, 461. 14 Kisku N, Joshi H, Ansari M, et al. Construction and Building Materials, 2017, 131, 721. 15 Verian K P,Ashraf W, Cao Y. Resources, Conservation and Recycling, 2018, 133, 30. 16 Knop Y, Peled A. Materer Structures, 2016, 49 (1), 439. 17 Zhang J L, Wu R S, Li Y M, et al. Applied Microbiology and Biotechno-logy,2016,100 (15),6661.