Title:
Enhanced Internal Curing for Ultra-High-Performance Concrete using a Reactive Curing Solution (Prepublished)
Author(s):
Weibo Tan, Peiyuan Chen, Ying Xu, Chunning Pei, Yi Fang, Jin Li, Xin Qian, and Jialai Wang
Publication:
Materials Journal
Volume:
Issue:
Appears on pages(s):
Keywords:
autogenous shrinkage; internal curing; internal relative humidity; UHPC; urea solution
DOI:
10.14359/51749446
Date:
1/12/2026
Abstract:
To address the autogenous shrinkage issue of ultra-high-performance concrete (UHPC), internal curing technology has shown great potential in resolving this challenge by providing additional moisture. To further improve its curing efficiency, this study proposes an innovative internal curing technology that can significantly reduce autogenous shrinkage without increasing the amount of internal curing water or compromising mechanical strength. This approach utilizes perforated cenospheres (PCs) as internal curing agents while substituting internal curing water with urea solutions. In addition to replenishing water, urea solutions, once released into the cement paste, can react with portlandite. This reaction generates CaCO₃; owing to the intrinsic properties of CaCO₃, it has a larger macroscopic volume and a much higher elastic modulus than portlandite. This approach effectively reduces chemical shrinkage while concurrently increasing the stiffness of the cement paste, thereby achieving a significant reduction in autogenous shrinkage. As a result, replacing water with 3% urea solution in PCs enhances the autogenous shrinkage of UHPC, reducing it from less than 50% to over 90%.