Compressive and electrical resistivity properties of UHPC containing different steel fibers

Abstract

This study is focused on investigating the self-sensing characteristices of smart UHPCs through evaluating the mechanical and electrical properties of ultra-high-performance concretes (UHPCs) containing different steel fiber types as functional fillers under compression. UHPCs containing 2 vol% stainless smooth fibers (6 mm in length and 0.2 mm in diameter, FL6) or 2 vol% brass coated smooth fibers (13 mm in length and 0.2 mm in diameter, FL13) or 2 vol% hybrid of FL6 and FL13 were prepared and evaluated. The test results indicated that The UHPC containing FL13 produced the highest compressive strength and the lowest electrical resistivity. The flowability and the volume weight of UHPCs were little influenced by fiber types. The UHPC with hybrid of FL6 and FL13 produced the highest fractional change in electrical resistivity (FCR) under compression. Besides, the correlation between FCR and compressive stress of UHPCs was obtained.

Keywords: Electrical resistivity; self sensing; steel fiber; structural health mornitoring; ultra high performance concrete.