ABSTRACT
The objective of this paper was to evaluate concrete properties after adding different proportions of sludge from a Water Treatment Plant (WTP), thus decreasing the generation of this environmental pollutant, which is originated by sanitation companies. In the present study, test specimens of concrete containing 5% and 10% of sludge from a WTP in substitution of sand, with the reference trace were made. The sludge used for concrete production was from a WTP partially responsible for the water treatment of Curitiba, where aluminum sulphate is used as coagulant. Firstly, a physical-chemical characterization of the collected sludge was performed determining the pH, analyzing the temperature, turbidity, COD, TS, humidity proportions and specific mass. Posteriorly, test specimens were made with dimensions of (10x20) cm and with the respective content of sludge to be incorporated. It was also evaluated the concrete hardened properties: compressive strength, tension strength of cylindrical specimens submit to diametrical compression and absorption. Considering the results, only sample with 5% of WTP sludge showed satisfactory conditions of resistance and axial compression when compared with the reference, with 15.5 MPa at 28 days and resistance loss around 11%. Therefore, the concrete made with the substitution of 5% of small aggregate may be used for non-structural finality, considering only the mechanical properties of the material because it is not possible to state about its durability. Studies like this are crucial in order to create solutions for the sludge generated in Water Treatment Plants.
Keywords:
Solid Wastes; Construction; Reuse; Compressive Strength; Absorption
