AVALIAÇÃO DO COMPORTAMENTO FÍSICO-MECÂNICO DO SOLO-CIMENTO AUTOADENSÁVEL ADICIONADO DE MICROFIBRAS SINTÉTICAS

Abstract

The viability of using the soil-cement material depends on the improvement of its physical and mechanical characteristics under aspects of durability, crack control and energetic expenditure on building system productivity. Therefore, this study analyzed the influence of adding polypropylene microfibers on altering the brittle behavior of the composite, as well as the fluidity of the soil-cement by adding a superplasticizer additive to reach the final product, self-compacting soil-cement with fibers (SCAAF). To this end, the granulometric characterization of the soil was carried out, the fluidization interval for obtaining the state of self-compactability was defined using the adapted slump flow test, and the behavior of the SCAAF was analyzed using the mechanical tests of simple compression, diametrical compression tensile and 4-point bending; and the physical tests of water absorption and linear shrinkage due to drying. The self-compacting soil-cement with the addition of fibers showed better physical and mechanical performance for the dosages with cement addition contents of 1:5 by mass of soil and superplasticizer additive of 1.2% by mass of cement at the spreading consistency of 320 mm, the addition of fibers directly influenced the dry apparent specific mass and porosity of the material, consequently, negatively affecting the compression and tensile strength, being relevant only in the post-cracking state, increasing the toughness of the SCAAF and reducing the fragility of the material. The SCAAF presented adequate launching and forming capacity for use in walls, without the need of compaction, presenting compression strength higher than 1.3 MPa at 7 days, and may be a viable alternative to construction methods with compaction of the soil-cement mixture, and is also a material with potential use in structures where it is necessary to reduce the brittle behavior of soil-cement.