https://doi.org/10.4322/2025360155501
R.B.A. VERONESE(1), W.A. MEDEIROS(2), C. MALUK(3), G.A. PARSEKIAN(4) and A.L. MORENO JR(5)
(1) PhD Candidate, Department of Civil Engineering, Federal University of São Carlos, São Carlos, São Paulo,
13565905, Brazil renatoveronese@estudante.ufscar.br
(2) Professor, Department of Civil Engineering, Federal Institute of Piauí, Teresina, Piauí, 64000040, Brazil
wamedeiros@ifpi.edu.br
(3) Professor, School of Civil Engineering, The University of Queensland, Brisbane, Queensland, 4072, Australia
c.maluk@sempergrp.com
(4) Professor, Department of Civil Engineering, Federal University of São Carlos, São Carlos, São Paulo, 13565905,
Brazil parsekian@ufscar.br
(5) Professor, Department of Civil Engineering, State University of Campinas, Campinas, São Paulo, 13083889,
Brazil armoreno@unicamp.br

ABSTRACT
A method to determine isotherms of concrete blocks is proposed in this work. The isotherm curves for each block in fire situations were determined from numerical models using Abaqus. The models were validated using experimental tests on block of three different strengths and of three different aggregate types. The specific heat, thermal conductivity, and weight density properties of the nine different vibropressed concretes were assessed at room temperature and at high temperatures. The residual compressive strength of the blocks after being exposed to high temperatures, as reported in previous work by the research group, were used to determine temperature θ1, the temperature up to which the cold strength of masonry may be used, and temperature θ2, the temperature above which the material has no residual strength. The results show that block thickness has great influence and aggregate type, and block strength both have a slight influence on concrete block’s thermal behaviour.

KEYWORDS: concrete block, isotherms, numerical modelling, fire situation, aggregate.