Estudo das propriedades de argamassas com a substituição parcial da areia pela cinza do lodo de ETE

Abstract

The sludge ash Sewage Treatment Plant (STP) sludge ash is a waste resulting from the effluent treatment process. Since its disposal in landfills is ineffective, measures to this waste have been researched, being one of them, the use as aggregate in mortars. In this scenario, the objective of this paper was to evaluate the characterization of sludge ash and to analyze the properties of mortars with the addition of different ash contents of the sludge ash in STP. First, a technical visit was made to the site to learn about the sewage treatment and collect the sample, which then underwent a pre-treatment to dry, burn and grind. The characterization of the materials was performed, being analyzed the particle size compositions, the specific mass and the unit mass. The reference trait chosen was 1: 3 (cement: sand), by mass, and comparative traits with partial replacement of sand by sludge ash in the proportions of 5% and 10%, by volume. Finally, the tests of mortar consistency index, compressive strength and specific mass in its hardened state were performed. Regarding the mortar, it was observed that for all composite strokes the compressive strength at 28 days reached higher values when compared to the reference trace, with a resistance increase of 90% and 148% for the 5% and 10% traces of sludge ash respectively. The trait with 10% substitution of sand by ash presented the highest specific mass.