水泥-粉煤灰-硅灰基超高性能混凝土水化过程微观结构的演变规律<sup>*</sup>

doi:10.11896/j.issn.1005-023X.2017.023.011

Abstract
Figure/Table
References
Related Citation (15)

Download:

Full Text ( PDF ) (1188KB)
Export: BibTeX | EndNote (RIS)

Abstract Ultra-high performance concrete (UHPC) is a promising material which exhibits extrodinary mechanical properties and durability. A UHPC paste containing fly ash and silica fume was prepared and its microstructure evolution during hydration was investigated with backscattered electron (BSE) images, thermogravimetry (TG) and nitrogen adsorption method. The results showed that the hydration of cement was fast at early ages, and it slowed down after 7 days. Due to its low activity, fly ash reacted slowly in the paste. The reaction degree of fly ash was only 7% by 28 days. The content of Ca(OH)₂ increased quickly at first as the cement hydrated. After 3 days it started to decline due to the consumption by pozzolanic reactions of silica fume and fly ash. There was still some Ca(OH)₂ existing in the paste by 28 days. Moreover, the specific surface area and the porosity of UHPC paste decreased as the curing progressed, resulting in a denser microstructure.

Key words： ultra-high performance concrete (UHPC) paste reaction degree calcium hydroxide pore structure hydration process

Published: 10 December 2017 Online: 2018-05-08

CLC number:

TU528

	Service
	E-mail this article
	Add to my bookshelf
	Add to citation manager
	E-mail Alert
	RSS
	Articles by authors
	WANG Qiannan
	GU Chunping
	SUN Wei

Cite this article:

WANG Qiannan,GU Chunping,SUN Wei. Microstructure Evolution During Hydration Process of Ultra-High Performance Concrete Containing Fly Ash and Silica Fume[J]. Materials Reports, 2017, 31(23): 85-89.

URL:

https://www.mater-rep.com/EN/10.11896/j.issn.1005-023X.2017.023.011 OR https://www.mater-rep.com/EN/Y2017/V31/I23/85

1 Gu C P, Ye G, Sun W. Ultrahigh performance concrete-properties, applications and perspectives [J]. Sci China Technol Sci, 2015, 58(4):587.
2 Shi C, Wu Z, Xiao J, et al. A review on ultra high performance concrete: Part I. Raw materials and mixture design [J]. Constr Buil-ding Mater, 2015, 101:741.
3 Radlinski M, Olek J. Investigation into the synergistic effects in ternary cementitious systems containing portland cement, fly ash and silica fume [J]. Cem Concr Compos, 2012, 34(4):451.
4 Wu Z, Shi C, He W. Comparative study on flexural properties of ultra-high performance concrete with supplementary cementitious materials under different curing regimes [J]. Constr Building Mater, 2017, 136:307.
5 Ridtirud C, Posi P, Chindaprasirt P. Development of high perfor-mance concrete containing high calcium fly ash [J]. Eng Appl Sci Res, 2016, 43:446.
6 Meng W, Valipour M, Khayat K H. Optimization and performance of cost-effective ultra-high performance concrete [J]. Mater Struct, 2016, 50(1):29.
7 Meng W, Khayat K H. Mechanical properties of ultra-high-perfor-mance concrete enhanced with graphite nanoplatelets and carbon nanofibers [J]. Compos Part B Eng, 2016, 107:113.
8 Zhao S, Sun W. Effect of silica fume and fly ash on pore structures of blended pastes at low water to binder ratios [J]. Adv Cem Res, 2015, 27(9):506.
9 Rong Z D, Sun W, et al. Effect of silica fume and fly ash on hydration and microstructure evolution of cement based compo-sites at low water-binder ratios [J]. Constr Build Mater, 2014, 51:446.
10 Weng J K, Langan B W, Ward M A. Pozzolanic reaction in portland cement, silica fume, and fly ash mixtures [J]. Canadian J Civil Eng, 1997, 24(5):754.
11 Wang D H. Hardening of ultra-high strength concrete [D]. Changsha: Hunan University, 2015(in Chinese).
王德辉. 超高强混凝土的硬化过程 [D]. 长沙: 湖南大学, 2015.
12 Feng X, Garboczi E J, et al. Estimation of the degree of hydration of blended cement pastes by a scanning electron microscope point-counting procedure [J]. Cem Concr Res, 2004, 34:1787.
13 Gu C P. Chloride transport property and service life prediction of UHPFRCC under flexural load [D]. Nanjing: Southeast University, 2016(in Chinese).
顾春平. 弯曲荷载作用下UHPFRCC的氯离子传输性能和服役寿命预测 [D]. 南京: 东南大学, 2016.
14 Ye G, Breugel K V, Fraaij A L A. Three-dimensional microstructure analysis of numerically simulated cementitious materials [J]. Cem Concr Res, 2003, 33(2):215.
15 Marsh B K, Day R L. Pozzolanic and cementitious reactions of fly ash in blended cement pastes [J]. Cem Concr Res, 1988, 18:301.
16 Zhang Q, Ye G, Koenders E. Investigation of the structure of hea-ted Portland cement paste by using various techniques [J]. Constr Building Mater, 2013, 38(2):1040.
17 Brunauer S, Emmett P H, Teller E. Adsorption of gases in multimolecular layers [J]. J Am Chem Soc, 1938, 60(2):309.
18 Barrett E P, Joyner L G, Halenda P P. The determination of pore volume and area distributions in porous substances. I. Computations from nitrogen isotherms [J]. J Am Chem Soc, 1951, 73:373.
19 Korpa A, Kowald T, Trettin R. Phase development in normal and ultra high performance cementitious systems by quantitative X-ray analysis and thermoanalytical methods [J]. Cem Concr Res, 2009, 39(2):69.
20 Huang W, Kazemi-Kamyab H, Sun W, et al. Effect of cement substitution by limestone on the hydration and microstructural development of ultra-high performance concrete (UHPC) [J]. Cem Concr Compos, 2017, 77:86.
21 Jennings H M. A model for the microstructure of calcium silicate hydrate in cement paste [J]. Cem Concr Res, 2000, 30(1):101.
22 Tennis P D, Jennings H M. A model for two types of calcium silicate hydrate in the microstructure of Portland cement pastes [J]. Cem Concr Res, 2000, 30(6):855.