Evaluation of the swelling pressure of the corumbatai formation materials

Abstract

Materials in which the change in moisture content leads to an increase in their volume are known as expansive soils, and may cause damages in engineering works. Due to lack of soil with better qualities, and the need to use these soils as construction materials, it is necessary to study this behavior. Tests were performed with the inundation of samples with distilled water by the constant volume method. In addition to the mineralogical and geotechnical tests (index properties), the samples were submitted to the methylene blue adsorption test and the scanning electron microscopy. Results of swelling tests showed higher swelling pressure for compacted air dried samples, with reached values about 200 kPa, while 133 kPa for undisturbed air dried samples. Low values of swelling pressures can be justified by the absence of minerals of smectites group. Finally, the results of swelling pressure tests were compared with the values obtained from relations proposed in the literature to predict swelling pressure of expansive soils.