Title:
Effect of Lightweight Aggregate on Early-Age Autogenous Shrinkage of Concrete
Author(s):
Tao Ji, Bin-bin Zhang, Yi-Zhou Zhuang, and Hwai-Chung Wu
Publication:
Materials Journal
Volume:
112
Issue:
3
Appears on pages(s):
355-364
Keywords:
coefficient of thermal expansion; early-age autogenous shrinkage; hardening phase; lightweight aggregate; liquid phase; skeletonformational phase
DOI:
10.14359/51687229
Date:
5/1/2015
Abstract:
The total early-age shrinkage and coefficient of thermal expansion of concrete were measured by a corrugated pipe system. The effects of prewetted and dry lightweight coarse aggregate (LWA) on the autogenous shrinkage of concrete at early age (1 day), including liquid phase, skeleton-formational phase, and hardening phase, were investigated and discussed. It was confirmed that the early-age autogenous shrinkage of concrete depends on the constraint intensity on the hardening cement paste (HCP) by coarse aggregate and the effective water-cement ratio (w/c). The effective w/c has a much stronger influence during the liquid phase than other two phases; however, the constraint imposed by coarse aggregate becomes the dominant factor during the skeleton-formational phase. During the hardening phase, concrete made with prewetted LWA expands; at the same time, the chemical shrinkage and self-desiccation are insignificant.