TY - JOUR
T1 - Water desorption characteristics of saturated lightweight fine aggregate in ultra-high performance concrete
AU - Shen, Peiliang
AU - Lu, Linnu
AU - Wang, Fazhou
AU - He, Yongjia
AU - Hu, Shuguang
AU - Lu, Jianxin
AU - Zheng, Haibing
N1 - Funding Information:
This work was financially supported by the National Key R&D Program of China (No. 2017YFB0310001 ) and the National Natural Science Foundation of China (No. 51772226 and U1305245 ).
Publisher Copyright:
© 2019 Elsevier Ltd
Copyright:
Copyright 2019 Elsevier B.V., All rights reserved.
PY - 2020/2
Y1 - 2020/2
N2 - In this study, the water desorption behavior of saturated lightweight fine aggregate (LWA) in ultra-high performance concrete (UHPC) was systemmically investigated using isothermal calorimetry, relative humidity (RH), mercury intrusion porosimetry, X-ray microtomography methods, etc. The LWA with high porosity and coarse pore structure exhibited high absorption and easy desorption at high RH. The results indicate that a large amount of water in LWA was released before setting, resulting in an increase of water to binder ratio, which had an adverse effect on the performance. However, the water absorbed in LWA released fast after 6 h, inducing an internal curing effect. Mechanism on a “four-stage desorption” driven by capillary pressure and RH gradient was proposed. The water desorption that is beneficial for the internal curing is calculated. The results indicated that the internal curing efficiency could be enhanced by increasing LWA content and reducing its pore size.
AB - In this study, the water desorption behavior of saturated lightweight fine aggregate (LWA) in ultra-high performance concrete (UHPC) was systemmically investigated using isothermal calorimetry, relative humidity (RH), mercury intrusion porosimetry, X-ray microtomography methods, etc. The LWA with high porosity and coarse pore structure exhibited high absorption and easy desorption at high RH. The results indicate that a large amount of water in LWA was released before setting, resulting in an increase of water to binder ratio, which had an adverse effect on the performance. However, the water absorbed in LWA released fast after 6 h, inducing an internal curing effect. Mechanism on a “four-stage desorption” driven by capillary pressure and RH gradient was proposed. The water desorption that is beneficial for the internal curing is calculated. The results indicated that the internal curing efficiency could be enhanced by increasing LWA content and reducing its pore size.
KW - Internal curing
KW - Lightweight fine aggregate
KW - Relative humidity
KW - Ultra-high performance concrete
KW - Water desorption
UR - https://www.scopus.com/pages/publications/85074888771
U2 - 10.1016/j.cemconcomp.2019.103456
DO - 10.1016/j.cemconcomp.2019.103456
M3 - Journal article
AN - SCOPUS:85074888771
SN - 0958-9465
VL - 106
JO - Cement and Concrete Composites
JF - Cement and Concrete Composites
M1 - 103456
ER -