Effects of temperature rising inhibitor and shrinkage reducing admixture on pore structure of early-age cement paste

被引:15
作者
Zhao, Haitao [1 ]
Xiang, Yu [1 ]
Zhang, Baitong [1 ,2 ]
Qin, Xiao [1 ,3 ]
Xu, Wen [4 ,5 ]
Wang, Wenbin [5 ]
Tian, Qian [5 ]
Liu, Jiaping [4 ]
机构
[1] Hohai Univ, Coll Civil & Transportat Engn, Nanjing 210098, Peoples R China
[2] State Grid Shandong Qingdao Elect Power Supply Co, Qingdao 266001, Peoples R China
[3] Sinopec Nanjing Engn & Construct Incorporat, Nanjing 211100, Peoples R China
[4] Southeast Univ, Coll Mat Sci & Engn, Nanjing 211189, Peoples R China
[5] Jiangsu Sobute New Mat Co Ltd, Nanjing 211103, Peoples R China
基金
中国国家自然科学基金;
关键词
Temperature rising inhibitor; Shrinkage reducing admixture; Pore structure; Cement paste; Early age; Low-field nuclear magnetic resonance; AUTOGENOUS SHRINKAGE; DRYING SHRINKAGE; WATER; HYDRATION; MICROSTRUCTURE; PERFORMANCE; STRENGTH; BEHAVIOR; RATIO; DEFORMATION;
D O I
10.1016/j.conbuildmat.2021.124896
中图分类号
TU [建筑科学];
学科分类号
0813 ;
摘要
High-strength and high-performance concrete (HSHPC) is frequently used in practical engineering, but HSHPC tends to crack at an early age because of the large temperature drop (temperature shrinkage) and autogenous contraction. Therefore, a temperature rising inhibitor (TRI) and a shrinkage reducing admixture (SRA) are adopted to improve the properties of HSHPC. The macroproperties of concrete are closely linked to its pore structure. In this paper, the effects of the water-to-cement ratio (w/c) and TRI and SRA contents on the pore size distribution (PSD) and porosity of early-age cement paste were tested by low-field nuclear magnetic resonance spectroscopy (LF-NMR). The test results showed that the PSDs of samples generally contain two peaks. The most probable pore diameter (MPPD) increases with the w/c and reduces with the TRI content and age. However, the MPPD changes only slightly with SRA content. For the same SRA or TRI content, the MPPD changes in samples containing both SRA and TRI are similar to those of samples with TRI or SRA only. However, the combined use of SRA and TRI has an apparent influence on the PSDs of samples. The porosity becomes large with the w/c and SRA content but declines with TRI content. The porosities of samples with both SRA and TRI addition are significantly lower than those of samples without the SRA and/or TRI at 28 days. A modified two-peaks model, which is adapted from the Shimomura and Maekawa model, is developed for cement pastes with the TRI and/or SRA. The curves of the modified two-peaks model coincide with the experimental data.
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页数:13
相关论文
共 44 条
[1]  
[Anonymous], 1999, C109C109M ASTM INT
[2]   Effects of water-cement ratio and curing time on the critical pore width of hardened cement paste [J].
Atahan, Hakan Nuri ;
Oktar, Osman Nuri ;
Tasdemir, Mehmet Ali .
CONSTRUCTION AND BUILDING MATERIALS, 2009, 23 (03) :1196-1200
[3]   MICROSTRUCTURE DETERMINATION OF CEMENT PASTES BY NMR AND CONVENTIONAL TECHNIQUES [J].
BHATTACHARJA, S ;
MOUKWA, M ;
DORAZIO, F ;
JEHNG, JY ;
HALPERIN, WP .
ADVANCED CEMENT BASED MATERIALS, 1993, 1 (02) :67-76
[4]   Effect of admixtures on the setting times of high-strength concrete [J].
Brooks, JJ ;
Johari, MAM ;
Mazloom, M .
CEMENT & CONCRETE COMPOSITES, 2000, 22 (04) :293-301
[5]   Embedded NMR sensors to monitor evaporable water loss caused by hydration and drying in Portland cement mortar [J].
Cano-Barrita, P. F. de J. ;
Marble, A. E. ;
Balcom, B. J. ;
Garcia, J. C. ;
Masthikin, I. V. ;
Thomas, M. D. A. ;
Bremner, T. W. .
CEMENT AND CONCRETE RESEARCH, 2009, 39 (04) :324-328
[6]   Influence of water-to-cement ratio and curing period on pore structure of cement mortar [J].
Chen, Xudong ;
Wu, Shenxin .
CONSTRUCTION AND BUILDING MATERIALS, 2013, 38 :804-812
[7]   The effects of shrinkage-reducing admixtures used in self-compacting concrete on its strength and durability [J].
Demir, Ilhami ;
Sevim, Ozer ;
Tekin, Emrah .
CONSTRUCTION AND BUILDING MATERIALS, 2018, 172 :153-165
[8]   Mercury porosimetry - An inappropriate method for the measurement of pore size distributions in cement-based materials [J].
Diamond, S .
CEMENT AND CONCRETE RESEARCH, 2000, 30 (10) :1517-1525
[9]   Reactive Molecular Simulation on Water Confined in the Nanopores of the Calcium Silicate Hydrate Gel: Structure, Reactivity, and Mechanical Properties [J].
Hou, Dongshuai ;
Zhao, Tiejun ;
Ma, Hongyan ;
Li, Zongjin .
JOURNAL OF PHYSICAL CHEMISTRY C, 2015, 119 (03) :1346-1358
[10]   A numerical study on chloride diffusion in freeze-thaw affected concrete [J].
Jiang, Wen-qiang ;
Shen, Xiao-han ;
Xia, Jin ;
Mao, Li-xuan ;
Yang, Jian ;
Liu, Qing-feng .
CONSTRUCTION AND BUILDING MATERIALS, 2018, 179 :553-565