Desempenho de concreto com a incorporação de resíduo de catalisador de petróleo e adição de fibra de polipropileno

Abstract

The use of industrial waste incorporated into the Portland cement concrete matrix is becoming increasingly common and results in lower consumption of raw materials, reduced environmental impact, cost optimization and can improve the intrinsic properties of the materials. Petroleum catalyst residue (REC) is a material resulting from the fluidized bed catalytic cracking process in oil refineries and has fine granulometry, a high specific surface area and particles ranging in size from 0.04 μm to 36 μm. The fact that the REC has a proportion of 54% silica shows its potential for pozzolanicity. The addition of polypropylene (PP) fibers to the concrete matrix has been investigated as a way of improving its resistance to tensile stress and cracking control. This work studied the synergistic influence of these two materials when used in the concrete matrix. Concrete samples were produced with the following dosages in relation to the total mass of Portland cement: dosage R, with 10% replacement of REC, dosage P, with the addition of 1% polypropylene fibers, and dosage RP, with 10% REC replacement plus the addition of 1% polypropylene fibers. The water/cement ratio used was 0.55 and the percentage of superplasticizing additive was 1% in relation to the mass of the binder. The axial compressive strength tests showed increases of between 4.09% (36.83 MPa) and 23.37% (43.65 MPa) compared to the control sample. In the diametral compressive tensile strength tests, both the concretes with added fibers and those with cement replaced by REC showed higher results than the control, with increases in the order of 9.45% (3.24 MPa) to 13.51% (3.36 MPa). Both samples with partial replacement of REC and with the addition of PP had a higher degree of porosity and void index than the reference. The results of the actual specific mass of all the samples were very close, which shows that, excluding the voids, the materials' matrices are similar. The control dosage obtained the highest average dynamic modulus of elasticity of 33.06GPa. The R, P and RP concretes had results of 31.27GPa, 32.25GPa and 32.27GPa, respectively. The incorporation of oil catalyst waste into concrete, combined with the addition of polypropylene fiber, is technically, environmentally and economically viable, as it reduces costs, promotes a circular economy and mitigates environmental impacts. This approach contributes to the reduction of CO2 emissions, while at the same time favoring the reuse of industrial waste and reducing the consumption of natural resources, promoting sustainability.