Experimental investigation of pozzolanic reaction and curing temperature-dependence of low-calcium fly ash in cement system and Ca-Si-Al element distribution of fly ash-blended cement paste

Wang, Tiao1; Ishida, Tetsuya1; Gu, Rui2; Luan, Yao3

2021-01-18

10.1016/j.conbuildmat.2020.121012

CONSTRUCTION AND BUILDING MATERIALS   影响因子和分区

0950-0618

1879-0526

Supplementary cementitious materials (SCMs) significantly improve concrete performance. However, the application of SCMs remains limited by their heterogeneity and variability. This study investigated the pozzolanic reaction and curing temperature-dependence of low-calcium fly ash in cement systems over 2 years. The experimental results show that fly ashes have different reactivities and temperature dependencies even though they have similar material properties. A modified tangential method was developed for thermogravimetric analysis of the calcium hydroxide content and chemically bound water of fly ash-blended cement paste. The chemical composition of an aluminium-modified calcium silicate hydrate (C-(A)-S-H) gel of fly ash-blended cement paste was studied by scanning electron microscopy-energydispersive X-ray spectroscopy (SEM-EDS) with image analysis. The experimental results show that as the Ca/Si ratio decreased in fly ash-cement paste, the Al/Si ratio increased. The Al/Si distribution of fly ash-blended cement paste varies widely from 0.05 to 0.50 with no specific maximum. The typical Ca/Si and Al/Si ratios of C-(A)-S-H gel in fly ash cement paste are approximately 1.40 and 0.25. (C) 2020 Elsevier Ltd. All rights reserved.

Fly ash Pozzolanic reaction degree Modified tangential method C-(A)-S-H gel SEM-EDS

SCI ; EI

英语

其他

Japan Society for the Promotion of Science["17H01284","19K15059"]

Construction & Building Technology ; Engineering ; Materials Science

Construction & Building Technology ; Engineering, Civil ; Materials Science, Multidisciplinary

WOS:000604573000076

ELSEVIER SCI LTD

20204109322749

Aluminum compounds ; Calcium silicate ; Temperature distribution ; Thermogravimetric analysis ; Curing ; Hydrated lime ; Silicate minerals ; Silicon ; Energy dispersive spectroscopy ; Pozzolanic materials ; Lime ; Scanning electron microscopy

Cement:412.1 ; Minerals:482.2 ; Nonferrous Metals and Alloys excluding Alkali and Alkaline Earth Metals:549.3 ; Thermodynamics:641.1 ; Chemistry:801 ; Chemical Reactions:802.2 ; Chemical Products Generally:804 ; Inorganic Compounds:804.2

MATERIALS SCIENCE

Web of Science

1.Univ Tokyo, Sch Engn, Dept Civil Engn, Concrete Lab,Bunkyo Ku, 7-3-1 Hongo, Tokyo 1138656, Japan
2.Southern Univ Sci & Technol, Core Res Facil, Shenzhen 518055, Peoples R China
3.Saitama Univ, Dept Civil & Environm Engn, Saitama 3388570, Japan

Wang, Tiao,Ishida, Tetsuya,Gu, Rui,et al. Experimental investigation of pozzolanic reaction and curing temperature-dependence of low-calcium fly ash in cement system and Ca-Si-Al element distribution of fly ash-blended cement paste[J]. CONSTRUCTION AND BUILDING MATERIALS,2021,267.

Wang, Tiao,Ishida, Tetsuya,Gu, Rui,&Luan, Yao.(2021).Experimental investigation of pozzolanic reaction and curing temperature-dependence of low-calcium fly ash in cement system and Ca-Si-Al element distribution of fly ash-blended cement paste.CONSTRUCTION AND BUILDING MATERIALS,267.

Wang, Tiao,et al."Experimental investigation of pozzolanic reaction and curing temperature-dependence of low-calcium fly ash in cement system and Ca-Si-Al element distribution of fly ash-blended cement paste".CONSTRUCTION AND BUILDING MATERIALS 267(2021).