AVALIAÇÃO DA INCORPORAÇÃO DE LODO DE ETE COMO ADIÇÃO MINERAL EM CONCRETOS

Abstract

The present work evaluated the replacement of cement by ETE sludge ash in obtaining Portland cement concretes. XRD tests, determination of the pozzolanic activity index, laser granulometry were carried out. Tests were carried out on the aggregates and on the ashes of the sludge granulometry tests (NM 248/03), determination of specific mass (NBR 16916/21) and determination of unit mass (NM 45/06). Concrete was prepared with 0%, 2.5% and 5% of waste. In concrete, workability (NBR 16889/20), axial compression strength (NBR 5739/18), void index and water absorption (NBR 9778/09) were evaluated. The XRD analysis demonstrates that the residue was essentially constituted by SiO2, which can be classified as pozzolan, proven by the IAP test where it reached a value above the minimum to consider it as an effectively pozzolanic material. As for workability, as sludge was added, the abatement decreased. As for the axial compression, for 2.5% of addition of sludge there was a 9% increase in strength and for the addition of 5% there was a 10% decrease. Regarding the analysis of axial compressive strength, we only obtained results greater than 30MPa, which allows its use for structural purposes. As for the void index and water absorption, adding 5% of sludge causes a slight reduction in the void index and water absorption.