Estudo da viabilidade do uso do massará lavado em substituição à areia na confecção de concreto na região de Teresina-PI

Abstract

Population growth and urban development advances increase the demand for minerals, especially in the fluvial terraces of the capital and adjacent areas. In Teresina-PI, where most of the city is located between the Poti and Parnaíba rivers, the use of sand in concrete production has become a common practice. However, in some Brazilian capitals, sand scarcity is leading to the use of alternative materials as fine aggregates in concrete manufacturing.In the Teresina region, the quality of sand used for concrete mixing is often unsatisfactory, with a fineness modulus below the standard established by ABNT (Brazilian Association of Technical Standards). This has raised concerns in the local construction industry, as concrete composed of sand as a fine aggregate often fails to meet the desired standards of mechanical strength.The lack of specific studies, the absence of proper processing, insufficient technical knowledge in the field, and improper use have led to the rejection of "massará" by construction professionals and a large part of Teresina’s population. This situation has resulted in the obsolescence of the material, leading to its devaluation in the regional market.This study aims to mechanically characterize concrete using washed "massará" as a fine aggregate replacement for sand while maintaining the same proportions of aggregates, water, and cement as conventional concrete. The cement used is CP IV-F 40, the same type employed in major concrete plants in Teresina. Granulometry tests, slump tests, and axial compression tests on cylindrical specimens were conducted. The test results showed that washed "massará" has a compressive strength similar to that of conventional concrete, demonstrating its viability as an alternative fine aggregate in concrete production. This study suggests a new alternative for concrete mixing, especially considering the increasing scarcity of aggregate deposits due to the high demand in the consumer market. Keywords: fine aggregate; massará; concrete.