Title:
On Concrete Properties during Heating and Cooling (Prepublished)
Author(s):
Patrick Bamonte, Fabienne Robert, and Thomas Gernay
Publication:
Materials Journal
Volume:
Issue:
Appears on pages(s):
Keywords:
compressive strength; fire; high temperature; hot tests; residual tests; thermal diffusivity
DOI:
10.14359/51749132
Date:
8/21/2025
Abstract:
The use of parametric/natural fires in the design of reinforced concrete structures in fire conditions requires an accurate definition of the temperature-induced evolution of the thermal and mechanical properties. Within this context, the characterization of four normal-strength concretes (fc20 = 4220-7000 psi [29-47 MPa]), with siliceous and carbonate aggregates are studied here as concerns the thermal diffusivity D (between 68 and 1644°F [20 and 900°C]) and under uniaxial compression after different thermal cycles, with reference maximum temperatures of 392, 752, and 1112°F [200, 400, and 600°C]. The results show that thermal diffusivity exhibits mostly irreversible behavior after exposure to temperatures over 1382°F [750°C]. As concerns the compressive strength, the hot and residual values (when TTtest = 68°F [20°C]) are, overall, in line with the most common standard provisions. Quite interestingly, the tests carried out at intermediate temperatures (with Ttest does not = Tmax and Ttest > 68°F [20°C]) highlighted a strength decay, which is not simply an interpolation between hot and residual values.