Thermal conductivity is the physical property of materials that measures their capacity to transfer heat by conduction, increased with increasing saturation, temperature, volumetric fraction and thermal conductivity of the aggregate and decreasing with the increase of the relation w / C. This property influences aspects as important as the fire behavior of reinforced concrete structures. On the other hand, the incorporation of polypropylene fibers, due to its physical, chemical and mechanical characteristics, improves its resistance and controls the cracking while the incorporation of steel fibers, modifies the nonlinear behavior of the structural concrete, especially in tensile, delaying the propagation of cracks and increasing their ductility. Based on the above premises, the objective of the present study is to compare the thermal conductivity of different concretes, without addition and with additions of polypropylene fibers and steel fibers in different percentages by weight of cement
