Incorporação de resíduo da celulose em um solo de comportamento laterítico: efeitos de diferentes teores de adição e períodos de cura na resistência ao cisalhamento

Abstract

The pulp mill in Brazil has grown substantially in recent years. Due this sector’s expansion, there are also growing concerns about the generation of solid waste and its adequate final destination. In parallel, new research in Civil Engineering has been developed to promote the reuse of these materials, reducing the extraction of natural resources and providing a more adequate destination for industrial waste. This study aimed to investigate the viability of incorporating grits waste from the pulp industry into a lateritic clay soil from Cruz Alta, Rio Grande do Sul, using direct shear tests. To achieve this goal, samples were prepared with different grit residue contents (5, 10 and, 15%) and subjected to different curing ages (0, 7, 14, 28, and 56 days). Resistance envelopes were constructed from direct shear tests under normal stresses of 50, 100 and, 200 kPa. In addition, the soil-grit mixtures were physically characterized and analyzed at a microstructural level using a scanning electron microscope. The shear strength parameters obtained showed significant increases in the cohesive intercept, especially for the mixture with adding10% of the waste, gradually with the different curing periods. However, the values of the internal friction angle of the mixtures, however, were lower than the reference value for the soil, with each soil-grits mixture showing different trends over the curing ages. In microstructural terms, the sample showed a reduction in macropores with the addition of the waste, as well as an orientation of the particles.