Compressive strength of colored concrete with iron oxide in the city of Teófilo Otoni in Minas Gerais

Abstract

This work analyzed the variations in the compressive strengths of colored concrete through the elaboration, manufacture and breaking of 18 proof bodies incorporated with pigments based on red iron oxide in the mixture, considering the presence of biotite in the aggregates present in the geological formation in the city Teófilo Otoni in state of the Minas Gerais. Colored concrete is not diffused in civil construction in the region and differs from conventional concrete, as it does not require the application of coating, being a type of exposed concrete. We used three types of concrete (T1, T2 and T3) and were defined with theoretical compressive strengths (fck) of 18 MPa, 25 MPa and 40 Mpa. Percentages of 0%, 3% and 6% iron oxide pigments were added to the mixture of 18 proof bodies and the compressive strengths were tested at 9 and 28 days. The most relevant result was T3P3 with 3% pigment, which obtained a resistance of 38.25 MPa for a theoretical fck of 40 MPa. The recommended percentage for addition to the concrete mixture in the Teófilo Otoni region is 3% of colored inorganic additives, as the experimental values obtained are close to the theoretical compressive strength expected at 28 days, being 15.83 MPa for fck 18 MPa, 12.74 MPa for the fck 25 MPa and 38.25 MPa for the fck 40 MPa.