Contribuição para o uso de argilas orgânicas de elevada plasticidade na construção de estradas

Abstract

High plasticity organic clays present numerous problems in road works due to its low load-bearing capacity and high level of volumetric changes resulting from variation in moisture content. This research intends to evaluate the possibility of using organic clays of high plasticity in road works. The confinement of soil in bags has been presented to geotechnical engineering as resource capable of answering three fundamental questions: ecology, economy and efficiency. In fact, this soil treatment technique presents results satisfactory from a technical point of view, avoids the environmental impacts inherent to the the use of traditional materials, makes work costs and execution times more profitable. In this sense, we tried to select two soil samples in the access road to Macaneta beach and a laboratory characterization was carried out. That characterization comprised the physical and mechanical characterization of soils in their natural state. The DG2 sample showed a CBR value of less than 3%. With a view to increasing the its CBR value, the sample was air-dried and subsequently confined in bags plastics being at optimal moisture content and at near-limit moisture content plasticity (±2% margin), respectively. With the DG2 sample confined in plastic bags, mechanical characterization was carried out through the CBR test adapted. When the DG2 sample was compacted to the optimum moisture content, the value of CBR ranged from 1.7% to 6.7% without and with confinement in plastic bags, respectively. When the DG2 sample was compacted at the moisture content close to of the plasticity limit, the CBR of the soil confined in plastic bags was 5.3%. The results of laboratory tests indicated a significant improvement in the value of CBR with the confinement of high plasticity organic clay in bags plastics, which allows its use in the body of the landfill in road works. The present work also presents cases of works and tests carried out with the soil confinement in bags.(NOSSA TRADUÇÃO)