Study of Thermal Conductivity in Mass Concrete With Polypropylene and Steel Fibers

Abstract

The aim of the study is to compare the influence of the thermal conductivity in heat absorption of mass concrete subjected to a thermal aggression by a direct fire test. Concrete elements with addition of polypropylene fibers in 1% to 2% and steel fibers in 1% and 2% by weight of cement have been tested and compared to concrete without additions. To this end, direct fire tests on cylindrical samples and thermal conductivity tests on cubic specimens have been carried out. The analysis of the results shows that the addition of polypropylene fibers contributes to improve the concrete fire performance, reducing the thermal conductivity and heat transfer towards the structural element, which minimizes the expansion - contraction effect and the appearance of fissures on the concrete specimen. Keywords: ? thermal conductivity; polypropylene fibers; steel fibers, concrete, fire