Análise de desempenho do aditivo linear alquil benzeno sulfonato de sódio como incorporador de ar em concreto

Abstract

Additives are chemicals that added to the mortar or concrete, in a less than 5% proportion, have the ability to modify and / or improve the properties of the concrete. Among the types of additives found on the market, there are air incorporators (AIAs) which are surface-active compounds that reduce the surface tension of the water and introduce stable air microbubbles into the concrete, improving its workability, cohesion and ice resistance and its melting. Detergent is currently used as an air incorporator additive because of its availability on the market, non-toxicity and because its chemical formula is similar to commercially available anionic surfactant additives. Therefore, the present work aims to evaluate the performance of the neutral detergent as an air incorporator additive for concrete compared to the commercial additive according to laboratory tests. Portland cement CP-II-Z, coarse aggregate and fine aggregate with 1: 2: 3 trace with an a / c ratio of 0.56 were used to make mixtures with neutral detergent, commercial additive and a reference one. For concrete in the fresh state, the consistency index and the incorporated air content were determined, and for concrete in the hardened state, compressive strength and water absorption tests were performed by immersion, producing four specimens for each trait, twenty-eight specimens in total. The results showed that the detergent is efficient as an air incorporator additive and, in comparison to the commercial additive, obtained, in general, a very similar behavior, but with a slightly lower performance.