Title

Effect of High Temperature Exposure and Strain Rate on Mechanical Properties of High-Strength Steel Rebars

Abstract

In this study, quasi-static tensile tests of high-strength steel rebars, after exposure to 20°C-1,300°C, and dynamic tensile tests at a strain rate of up to 0.25 s-1, after exposure to 20°C-900°C, were conducted to understand the effect of elevated temperature and strain rate on the mechanical properties of the high-strength steel rebars. The coupled effect of high temperature exposure and strain rate was discovered; the strength equation and the constitutive model of high-strength steel rebars were proposed with the coupled effect taken into account. Specifically, the color and weight of steel rebars, after exposure to above 700°C, change significantly because of oxidation. High temperature significantly affects the fracture morphology of rebars when statically tested, but it has little effect when dynamically tested. High-strength rebars begin to degrade at 500°C with their residual yield and ultimate strength remaining greater than 60% and 70%, respectively, after exposure to temperatures above 900°C. Their strengths are affected by strain rate more significantly at higher temperatures because of microstructural changes. The hardening strain is related to both temperature and strain rate; the ultimate strain is affected by temperature only.

Department(s)

Civil, Architectural and Environmental Engineering

Research Center/Lab(s)

INSPIRE - University Transportation Center

Comments

The authors appreciate the financial support from the National Science Foundation of China (Nos. 51522905, 51778570, and 51879230), the Zhejiang Provincial Natural Science Foundation of China (No. LR15E090001), and the Fundamental Research Funds for the Central Universities (No. 2019QNA4044).

Keywords and Phrases

Constitutive model; High temperature; High-strength steel rebar; Mechanical properties; Microstructure; Strain rate

International Standard Serial Number (ISSN)

0899-1561; 1943-5533

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2019 American Society of Civil Engineers (ASCE), All rights reserved.

Publication Date

01 Nov 2019

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