Per: MARKSSUEL TEIXEIRA MARVILA (UFV - CRP), Bárbara Raphaela Alves Costa (UFV - CRP), Isadora Marques Santos (UFV - CRP), Marina Rabelo Brito (UFV - CRP), Sirgê de Melo Junior (ufv - crp), Jose Alexandre Tostes Linhares Júnior (UENF), afonso rangel garcez de azevedo (UENF)
Abstract:
The quality of the mixing water is crucial to guarantee the properties and quality of cementitious materials. Water plays an essential role in the mixing of aggregates and in the hydration processes, so it is essential that it complies with regulatory criteria. Studies demonstrate the negative effects of impure water on concrete, including interference with resistance, staining and changes in the cement's setting. NBR 15900-1 establishes verification parameters, maximum limits for contaminant concentrations and test procedures for determining water quality. The adoption of adequate quality standards is essential to prevent pathologies, such as corrosion of reinforcement, highlighted by studies. The present work aimed to evaluate the behavior of mortars using contaminated water containing 5% chlorides, and another with 5% hydroxides in its compositions. To this end, the consequences and applications of contaminating compositions were evaluated in the criteria of consistency, water absorption, compressive strength in 7 and 28 days, and pH analysis of the specimens. It can be concluded that the addition of contaminated kneading water in sample preparation led to a significant drop in compressive strength when compared to the reference sample. It was observed that the composition containing chloride absorbed more water and consequently had its compressive strength at 28 days compromised by more than 95%. As evidenced by studies, chloride, in concentrations outside the recommended limits, presents an exponential reduction in the performance of cementitious materials, enabling the emergence of pathologies and potentially compromising the interim use of the structure. Finally, the continued importance of evaluating and guaranteeing the water standards required for the adequate production of these materials is highlighted.
