Embankment construction with limestone powder waste: From laboratory to full-scale implementation

Limestone powder waste is a by-product generated in the polishing and cutting activities of the natural stone industry. In this research, the effect of limestone powder waste as an additive, either alone or in combination with hydrated lime, on the geotechnical properties of three clayey soils has been studied. Moreover, the suitability of limestone powder waste as a standalone material for embankment construction has been assessed. The geotechnical properties were measured in the laboratory by the Proctor, free swell, CBR, unconfined compressive strength and oedometer tests. A full-scale embankment was also constructed with four different sections combining natural soil, limestone powder waste, and lime. A final section with only limestone powder was also constructed. The strength and deformability of these sections were assessed by the plate load test, the dynamic probe test and the footprint test. The laboratory test results indicate a general improvement in the strength and deformability of the soil when mixed with limestone powder waste. The strength increased by up to 88%, while the deformation was reduced by 32% when the by-product was added to the natural soil. When added to the soil and lime samples the strength increased by up to 59% and the deformation was reduced by 15%. The in-situ tests confirmed a reduction in deformability of up to 83% and an increase in soil strength when the by-product was added. Finally, the section with only limestone powder showed less deformability than the others, indicating that this by-product can be used for road embankment construction.