Evaluation of the Effect of Temperature (20–700 °C) on the Properties of Prestressing Steel Using AE Signals and FEM Analysis

Sep 30, 2026

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The study presents a comprehensive analysis of the effects of high temperatures (500 °C and 700 °C) on the microstructure, mechanical properties, and acoustic emission (AE) parameters of cold-drawn prestressing steel. Mechanical testing and AE signal acquisition are combined with finite element method (FEM) numerical verification. Higher temperatures induce pronounced microstructural changes (pearlite spheroidisation, carbide coarsening), causing strength degradation and shifting failure from quasi-brittle to transitional and finally ductile behavior. AE features (Counts to Peak, RA value) correlate with ε22 strain and von Mises stress, enabling identification of the onset of load-bearing capacity loss and critical damage thresholds, and supporting a multi-criteria post-fire diagnostic indicator.

LanguageEnglish

CategoryResearch & Report

FormatPDF

Pages20

Reading Time50 min

AccessFree to download

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1. Introduction

Article Evaluation of the Effect of Temperature (20–700 ◦ C) on the Properties of Prestressing Steel Using AE Signals and FEM Analysis Anna Adamczak-Bugno 1, *, Sebastian Michał Lipiec 2 and Jakub Adamczak 1 Academic Editors: Seong-Ho Ha and Young-Ok Yoon Received: 25 November 2025 Revised: 14 December 2025 Accepted: 17 December 2025 Published: 20 December 2025 Corrected: 14 February 2026 Copyright: © 2025 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license. 1 Faculty of Civil Engineering and Architecture, Kielce University of Technology, Av. 1000-An. of Polish State 7, 25-314 Kielce, Poland; [jakubadamczak123@gmail.com](jakubadamczak123@gmail.com) 2 Faculty of Mechatronics and Mechanical Engineering, Kielce University of Technology, Av. 1000-An. of Polish State 7, 25-314 Kielce, Poland; [slipiec@tu.kielce.pl](slipiec@tu.kielce.pl) * Correspondence: [aadamczak@tu.kielce.pl](aadamczak@tu.kielce.pl) Highlights What are the main findings? • High temperature causes significant strength degradation and changes the failure mechanism. • AE parameters (Counts to Peak, RA-value) effectively identify the onset of damage. What are the implication of the main findings? • AE was correlated with the ε 22 strain and von Mises stress (FEM) . • A criterion was developed to determine the moment of load-bearing capacity loss after fire exposure. Abstract The study presents a comprehensive analysis of the effects of high temperatures (500 ◦ Cand 700 ◦ C) on the microstructure, mechanical properties, and acoustic emission (AE) parameters of cold-drawn prestressing steel. The investigations included mechanical testing, AE signal acquisition, and numerical verification using the finite element method (FEM) . It was demonstrated that increasing temperature leads to significant microstructural changes (pearlite spheroidisation, carbide coarsening), resulting in strength degradation and a shift in the failure mechanism from quasi-brittle (initial state) to transitional (500 ◦ C), and finally to ductile (700 ◦ C) . For the first time, AE parameters (Counts to Peak and RAvalue) were correlated with local axial strains ε 22 and von Mises equivalent stress, enabling the identification of the moment of onset load-bearing capacity loss and the determination of critical material damage thresholds. A multi-criteria diagnostic indicator was proposed to assess the condition of prestressing steel after fire exposure. The results confirm the high potential of AE as a non-invasive tool for evaluating the safety of prestressing tendons and cables in reinforced concrete structures subjected to overheating or fire. Keywords: prestressing steel; uniaxial tensile test; stress and strain curve; acoustic emission method; finite element method 1. Introduction In recent years, a dynamic development of metallurgical technologies has been observed, which has led to the creation of modern grades of reinforcing steels characterised by increased strength and service durability. Of particular importance within this group of materials are prestressing steels, widely used as reinforcement in prestressed concrete (PC) elements. Owing to a carefully selected chemical composition, including an increased carbon content and controlled alloying additions, as well as the use of advanced thermomechanical treatment processes such as strain hardening, quenching, and tempering, it is possible to achieve very high yield strength levels (1600–1800 MPa) [1–3] . The use of prestressing steels enables a significant reduction in structural weight, an increase in loadbearing capacity and stiffness, and an improvement in resistance to cracking and creep. As a result, these steels are finding increasingly wide application in bridge and building engineering, as well as in structures with elevated durability requirements [4

FAQs

How do high temperatures affect prestressing steel strength and failure mode?

Increasing temperature leads to significant strength degradation and a shift in the failure mechanism from quasi-brittle behavior to transitional behavior around 500 °C, and ultimately to ductile behavior at 700 °C.

Which AE parameters were used to detect damage onset?

The study uses AE parameters including Counts to Peak and RA value to identify the onset of damage and to link acoustic features to structural response.

How were AE results validated and related to stress–strain quantities?

AE was correlated with ε22 strain and von Mises equivalent stress, supported by numerical verification using the finite element method (FEM).

What diagnostic capability does the study propose after fire exposure?

A multi-criteria diagnostic indicator is proposed to assess the condition of prestressing steel after fire, enabling determination of critical material damage thresholds and the moment of load-bearing capacity loss.

Sep 30, 2026

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