Dimensional influence of basalt fiber reinforcements on the consolidation behaviour of rice husk ash stabilized soils

Abstract

The development of reinforcement techniques in soils with various fibers has been a common practice since the early days. Recently, fibers and materials considered waste are being used to develop sustainable solutions in designing new soil reinforcing and stabilizing materials. In this paper, an investigation has been carried out to evaluate the dimensional influence of basalt fiber on the compressibility and swelling of soils stabilized with rice husk ash (RHA) and cement. Incorporating a nominal dosage of basalt fibers into the soil–cement-RHA composite produces a strong composite with smart material properties. Specimen containing expansive clay soil, basalt fibers (lengths 3 mm, 6 mm, 12 mm), RHA (5%, 10%, and 15%), and cement (3%), in their specified combinations, were prepared and tested. The influence of fiber length and variation of RHA-cement content was quantified using the consolidation curves (compression curves and normalized compression curves), compression index, and swelling index, which provided a detailed behavioral modification upon consolidation. Scanning Electron Microscopy (SEM) and X-ray powder diffraction (XRD) were also used to examine the reconstituted soil structure and chemical components. It is demonstrated that a reconstituted clay soil combination of 12 mm basalt fibers, 5% RHA, and 3% cement, enhanced the ultimate yield pressures and the resistance to excessive swelling. This paper emphasized the projected responses during the loading and unloading phases on the specimen and discussed the consolidation characteristics of the newly reconstituted soil composites.