Desempenho de tijolo maciço de solo-cimento com incorporação de concentrado de vermiculita esfoliada para alvenaria ecológica

Abstract

The economic development of a country is directly related to the construction sector. Among the most used materials, ceramic blocks stand out for their easy access and low cost, however, their production does not have a sustainable bias. In this scenario, the soil-cement solid brick (SCSB) presents itself as an ecological alternative, as well as the incorporation of secondary raw materials. In this context, the proposal of the work was to incorporate exfoliated Vermiculite concentrate (EV) in SCSB. For this, the natural Vermiculite concentrate (NV) was thermally treated at 800°C, for periods of 10 min (EV 800/10) and 15 min (EV 800/15). Both NV and EV were characterized regarding morphological, physical, chemical, microstructural and thermal properties. For the soil, physical, microstructural, chemical and morphological characterizations were performed. Finally, SCSB was characterized in terms of water absorption properties, compressive strength, and thermal and acoustic insulation, before and after accelerated aging. The soil met the limits established by the standard, not requiring corrections. NV was classified as superfine material with a content of 83.33 %. The most efficient thermal treatment was EV 800/15, with increases in specific surface area and pore volumes and radii, and therefore used in the production of SCSB. Three treatments were made, replacing the soil volume with EV 800/15; at 0, 2.5 and 5 %. The results for water absorption met the limits established by NBR 8491 (ABNT, 2012), however, compressive strengths were lower than the minimums established by the standard. The acoustic barrier significantly increased in T3 after aging, with a 19 % increase. In terms of thermal conductivity, there was a trend of reduction in values, according to the incorporation of EV, in the aged treatments. It is concluded that SCSB with EV incorporation cannot be used for this purpose, due to the mechanical results not meeting the standard, however, all other properties improved, indicating a potential application where the necessary compressive strength is less than 1 MPa.