Estudo sobre o uso do lodo das estações de tratamento de água como substituição de porcentagens do cimento em matrizes de concreto não estrutural

Abstract

The degradation of the environment and water resources has increased over the years, given that with increasing population the demand for drinking water and the poor quality of rivers require higher concentrations of chemicals at Water Treatment Stations (WTSs), leading to a higher generation of waste, called WTS sludge. The correct disposal of this sludge has been a concern for years and one of the most commonly used alternatives for the disposal of this waste is its disposal in waterways, even though it is considered a solid waste and can cause serious environmental impacts. In order to give a more correct disposition to this sludge, which is a great polluting agent, this study aims at the co-disposal of this residue, dry and ground, in non-structural concrete matrices, replacing cement percentages. extraction also causes environmental impacts. For this, a concrete reference (without mud substitution) and traces with substitution of 5, 10 and 15% of sludge in relation to the weight of the cement was used. The properties of the fresh concrete were evaluated through the workability and hardened, with tests of resistance to compression and water absorption. The analysis of the data allowed concluding that all the dosages are feasible from the point of view of the compressive strength, being able to be applied in situations that go from the manufacture of blocks until the construction of rigid pavements. Regarding the workability, however, mixtures above 10% of substitution can be applied in situations where this characteristic is not a primordial parameter. In general, the substitutions of percentages of cement by dry and ground sludge proved to be feasible both in the environmental and economic spheres.