Introducing artificial flaws in Engineered cementitious composites (ECC) through nanocomposite coating of aggregates: A novel approach and mechanism
Zhuo Tang, Cheng Li, Jing Zhong
Abstract
This study introduces a novel method for incorporating artificial flaws in Engineered Cementitious Composite (ECC) by applying carbon nanotube (CNT) polymer nanocomposite coatings, which has a porous microstructure, to aggregates. In comparison with the control ECC, the implementation of coated aggregates can improve the crack number and the strain capacity of ECC by 268 % and 83.7 %, respectively, while only incurring a 14.1 % decrease in compressive strength . Furthermore, increasing the sand-to-binder (s/b) ratio from 0.36 to 0.75 can improve the strain capacity of ECC by 213.1 %, with a reduction of compressive strength by 22.6 %. The underlying mechanisms were investigated both experimentally and theoretically, which revealed that the reduced spacing between artificial flaws significantly increases the stress concentration factor , thereby facilitating crack initiation and propagation. The simplicity, cost-effectiveness, and general applicability of this coating technique offer a valuable method for enhancing the performance of ECC, which could substantially advance its practical applications.