Title: Methodology for Predicting Concrete Strength after Short- Term Heat Exposure

Author(s): Stephen Wright and Laura Redmond

Publication: Materials Journal

Volume: 120

Issue: 6

Appears on pages(s): 33-46

Keywords: concrete strength; heat exposure; predictive model; residual strength; short duration

DOI: 10.14359/51739145

Date: 12/1/2023

Abstract:
Exposure to high temperature is well known to cause concrete degradation and lead to compressive strength loss. However, most research focuses on concrete exposed to high temperatures for more than 1 hour, and the available predictive equations for concrete strength loss due to heat exposure do not consider the effects of concrete thermal mass or account for variation in concrete thermal properties. This work proposes a methodology to create a predictive equation for the compressive strength loss in concrete exposed to heat. The proposed method leverages concrete temperature data from transient thermal analyses of concrete specimens correlated to results from experimental testing. The resulting equation from the analyzed data set predicted compressive strength loss with a root-mean-square error (RMSE) of 1.35% absolute error of the measured strength loss, and the maximum absolute underprediction in strength loss was 12.4% across all 26 cases examined.