Improvement of the stress sensing ability of ultra-high-performance concrete using short steel fibers and steel slag aggregates under high compression
Huy Viet Le, Phúc Lâm Đào, Sy Duc Nguyen, Tri Thuong Ngo, Ngoc Thanh Tran, Duy Liem Nguyen, Dong Joo Kim
Abstract
Smart ultra-high-performance concrete (smart UHPC) with self-sensing capacity in addition to high mechanical resistance has been recently developed as one of potential construction materials for structural health monitoring systems of infrastructures, e.g., smart anchorage head for monitoring stress loss of tendons in pre-stressed concretes. This study aims to further enhance the stress sensing ability, specifically maximum stress sensing (σ m ) and fractional change in electrical resistivity (FCR) of smart UHPCs, by employing both short steel fibers and fine steel slag aggregates . Test results indicated that the smart UHPC (containing 5 vol% short steel fibers) produced the highest stress sensing characteristics (σ m up to 200.6 MPa and FCR of 33.7%). Besides, the smart UHPC (containing 4 vol% short steel fibers and FSSAs) produced the highest FCR (6.16%) at 0.3σ m in the elastic region owing to the enhanced tunneling and contacting conductions of functional fillers . Furthermore, the correlation between the FCR and the compressive stress of smart UHPCs was proposed.