Influence of Accelerator Main Components on Hydration and Mechanical Properties of Portland Cement

被引：0
|
作者：
Zhang G. [1 ]
机构：
[1] School of Civil Engineering, Beijing Jiaotong University, Beijing
来源：
Zhang, Ge (975630177@qq.com) | 1600年 / Science Press卷 / 42期
关键词：
Aluminum sulfate; Hydration degree; Hydration product; Mechanical properties; Pore structure; Sodium aluminate;
D O I：
10.3969/j.issn.1001-8360.2020.01.016
中图分类号：
学科分类号：
摘要：
Accelerator is one of the important materials in shotcrete construction. Sodium aluminate and aluminum sulfate, as the main components of alkali and non-alkali accelerators, which are referred to NA and AS respectively, have significant influence on the properties of shotcrete. The effects of sodium aluminate (NA) and aluminum sulfate (AS) on the hydration degree, hydration product, pore structure and mechanical properties of Portland cement paste were investigated using non-evaporative water test, thermos gravimetric analysis, mercury intrusion porosimetry (MIP) and strength tests. The results show that NA and AS increased the early hydration rate of cement, reduced total porosity and most probable pore size in the paste, improved the compressive strength of hardened cement paste at 1 d and generated early characteristic hydration products 3CaO•Al2O3•CaSO4•12H2O and 3CaO•Al2O3•3CaSO4•32H2O, which are referred to AFm and AFt respectively. After 1 day, NA and AS both slowed down the hydration rate and pore structure refinement of cement, which produce adverse impact on the development of compressive strength. After 28 days, the number of harmless pores in the hardened cement paste mixed with NA and AS was less than that in the blank group and the number of harmful pores and multiple harmful pores was more than that in the blank group. The compressive strength of NA and AS cement paste decreased to a certain extent compared with blank group. The content of harmless pores, harmful pores and multiple harmful pores in the hardened cement paste mixed with AS is between blank group and NA, while the compressive strength reduction degree is lower than NA. © 2020, Department of Journal of the China Railway Society. All right reserved.
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页码：112 / 118
页数：6
相关论文
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