SAP内养护对碱激发矿渣胶凝材料性能的影响

硅酸盐通报 ›› 2021, Vol. 40 ›› Issue (10): 3435-3441.

SAP内养护对碱激发矿渣胶凝材料性能的影响

李相国, 许金生, 姜东兵, 吕阳, 何晨昊, 张乘, 傅秋艳

武汉理工大学,硅酸盐建筑材料国家重点实验室,武汉 430070

收稿日期:2021-04-07 修回日期:2021-05-11 出版日期:2021-10-15 发布日期:2021-11-11
通讯作者: 吕阳,博士,研究员。E-mail:yang.lv@whut.edu.cn
作者简介:李相国(1976—),男,博士,研究员。主要从事水泥、工业固废等方向的研究。E-mail:lxggroup@163.com
基金资助:
国家自然科学基金青年科学基金(51808420);中央高校基本科研业务费专项资金资助(2019IVB058)

Effect of Internal Curing of SAP on Properties of Alkali-Activated Slag Cementitious Materials

LI Xiangguo, XU Jinsheng, JIANG Dongbing, LYU Yang, HE Chenhao, ZHANG Cheng, FU Qiuyan

State Key Laboratory of Silicate Materials for Architectures, Wuhan University of Technology, Wuhan 430070, China

Received:2021-04-07 Revised:2021-05-11 Online:2021-10-15 Published:2021-11-11

摘要/Abstract

摘要： 碱激发矿渣(AAS)胶凝材料存在早期收缩大、开裂风险高的问题,限制了其工程应用。本文采用TAM、TGA、MIP等方法研究了高吸水性树脂(SAP)内养护对AAS胶凝材料水化热、水化产物及孔结构的影响,同时研究了SAP对AAS胶凝材料抗压强度及自收缩的影响规律。结果表明,SAP的加入会增加基体的孔隙率,降低AAS浆体的抗压强度,但是随着水化时间的延长,SAP的内养护作用可以促进矿渣水化,抗压强度的降低幅度逐渐减小。SAP的加入对AAS胶凝材料的水化放热过程有一定的延迟作用,表现为诱导期延长,第二放热峰滞后。SAP的加入使AAS胶凝材料水化产物总量增加,增加程度随着模数的增加而提高。此外,SAP抑制AAS浆体自收缩效果明显,添加SAP之后自收缩降低率最高可达81%。

关键词: 胶凝材料, 碱激发矿渣, 内养护, 高吸水性树脂, 力学性能, 水化特性, 自收缩

Abstract: Alkali-activated slag (AAS) cementitious materials have the problems of large early shrinkage and high cracking risk, which limit their engineering applications. In this study, superabsorbent polymer (SAP) was used as internal curing material to investigate its influence on the hydration heat, hydration products and pore structure of AAS cementitious materials by means of TAM, TGA and MIP, respectively. Moreover, the effect of SAP on the compressive strength and autogenous shrinkage of AAS cementitious materials were also studied. The results show that the addition of SAP increases the porosity of the matrix, and thus results in the decrease of compressive strength of AAS pastes. With the extension of hydration time, the internal curing effect of SAP promotes the hydration of slag, and the strength reduction is slightly compensated. The addition of SAP has a delay effect on the hydration exothermic process, which prolongs the induction period and leads to the lagging of the second exothermic peak. Furthermore, internal curing of SAP increases the content of hydration products, particularly for AAS pastes with higher modulus. The autogenous shrinkage of AAS pastes with SAP are obviously reduced compared with that of reference samples, and the maximum autogenous shrinkage reduction rate is reached up to 81%.

Key words: cementitious material, alkali-activated slag, internal curing, superabsorbent polymer, mechanical property, hydration property, autogenous shrinkage

中图分类号:

TQ177

李相国, 许金生, 姜东兵, 吕阳, 何晨昊, 张乘, 傅秋艳. SAP内养护对碱激发矿渣胶凝材料性能的影响[J]. 硅酸盐通报, 2021, 40(10): 3435-3441.

LI Xiangguo, XU Jinsheng, JIANG Dongbing, LYU Yang, HE Chenhao, ZHANG Cheng, FU Qiuyan. Effect of Internal Curing of SAP on Properties of Alkali-Activated Slag Cementitious Materials[J]. BULLETIN OF THE CHINESE CERAMIC SOCIETY, 2021, 40(10): 3435-3441.

参考文献

[1] PROVIS J L. Geopolymers and other alkali activated materials: why, how, and what?[J]. Materials and Structures, 2014, 47(1/2): 11-25.
[2] REES C A, PROVIS J L, LUKEY G C, et al. The mechanism of geopolymer gel formation investigated through seeded nucleation[J]. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2008, 318(1/2/3): 97-105.
[3] 顾亚敏,方永浩.碱矿渣水泥的收缩与开裂特性及其减缩与增韧[J].硅酸盐学报,2012,40(1):76-84.
GU Y M, FANG Y H. Shrinkage, cracking, shrinkage-reducing and toughening of alkali-activated slag cement: a short review[J]. Journal of the Chinese Ceramic Society, 2012, 40(1): 76-84 (in Chinese).
[4] YANG L Y, JIA Z J, ZHANG Y M, et al. Effects of nano-TiO₂ on strength, shrinkage and microstructure of alkali activated slag pastes[J]. Cement and Concrete Composites, 2015, 57: 1-7.
[5] 姚晓乐,江星,朱效宏,等.高吸水性树脂对碱矿渣水泥砂浆强度与收缩性能的影响[J].混凝土与水泥制品,2017(6):6-11.
YAO X L, JIANG X, ZHU X H, et al. Influence of super absorbent polymer on strength and shrinkage properties of alkali activated slag cement mortar[J]. China Concrete and Cement Products, 2017(6): 6-11 (in Chinese).
[6] JENSEN O M, HANSEN P F. Water-entrained cement-based materials[J]. Cement and Concrete Research, 2001, 31(4): 647-654.
[7] JUSTS J, WYRZYKOWSKI M, BAJARE D, et al. Internal curing by superabsorbent polymers in ultra-high performance concrete[J]. Cement and Concrete Research, 2015, 76: 82-90.
[8] LI Z M, ZHANG S Z, LIANG X H, et al. Internal curing of alkali-activated slag-fly ash paste with superabsorbent polymers[J]. Construction and Building Materials, 2020, 263: 120985.
[9] SONG C, CHOI Y C, CHOI S. Effect of internal curing by superabsorbent polymers: internal relative humidity and autogenous shrinkage of alkali-activated slag mortars[J]. Construction and Building Materials, 2016, 123: 198-206.
[10] CHEN W W, LI B, WANG J, et al. Effects of alkali dosage and silicate modulus on autogenous shrinkage of alkali-activated slag cement paste[J]. Cement and Concrete Research, 2021, 141: 106322.
[11] JENSEN O M, LURA P. Techniques and materials for internal water curing of concrete[J]. Materials and Structures, 2006, 39(9): 817-825.
[12] FANG G H, BAHRAMI H, ZHANG M Z. Mechanisms of autogenous shrinkage of alkali-activated fly ash-slag pastes cured at ambient temperature within 24 h[J]. Construction and Building Materials, 2018, 171: 377-387.
[13] SINGH B, RAHMAN M R, PASWAN R, et al. Effect of activator concentration on the strength, ITZ and drying shrinkage of fly ash/slag geopolymer concrete[J]. Construction and Building Materials, 2016, 118: 171-179.
[14] 赖俊英,童彦伟,詹树林,等.额外引水条件及高吸水性树脂掺加方式对砂浆收缩和孔结构的影响[J].东南大学学报(自然科学版),2018,48(5):903-910.
LAI J Y, TONG Y W, ZHAN S L, et al. Effects of extra water and adding modes of super-absorbent polymer on shrinkage and pore structure of mortar[J]. Journal of Southeast University (Natural Science Edition), 2018, 48(5): 903-910 (in Chinese).
[15] FU C Q, YE H L, LEI A K, et al. Effect of novel superabsorbent polymer composites on the fresh and hardened properties of alkali-activated slag[J]. Construction and Building Materials, 2020, 232: 117225.
[16] 孔祥明,李启宏.高吸水性树脂对水泥砂浆体积收缩及力学性能的影响[J].硅酸盐学报,2009,37(5):855-861.
KONG X M, LI Q H. Influence of super absorbent polymer on dimension shrinkage and mechanical properties of cement mortar[J]. Journal of the Chinese Ceramic Society, 2009, 37(5): 855-861 (in Chinese).
[17] FANG Y, KAYALI O. The fate of water in fly ash-based geopolymers[J]. Construction and Building Materials, 2013, 39: 89-94.
[18] LEE N K, JANG J G, LEE H K. Shrinkage characteristics of alkali-activated fly ash/slag paste and mortar at early ages[J]. Cement and Concrete Composites, 2014, 53: 239-248.