Evaluation of stiffening behavior of concrete based on contactless ultrasonic system and maturity method

Abstract

This study proposes an innovative contactless ultrasonic system (CUS) for monitoring the hardening behavior of concrete under accelerated curing, without any penetration or embedment of measurement devices. Two different concrete mixtures types were tested under several temperature-controlled environments, and the maturity method was used to calibrate the temperature effect on setting times. The conventional Penetrometer test results were compared with those of CUS. The equivalent ages as per the Penetrometer test and CUS results showed maximum differences of 8 h and less than 1.6 h, respectively. The CUS demonstrated promising results regarding hardening behavior without sampling procedures, which has advantages regarding accelerated curing. It is thus a potential alternative to the existing setting time measurement methods regarding practicality and accuracy. © 2020 Elsevier Ltd