Impacts of Lime and Ground Granulated Blast Furnace Slag on Soil Stabilisation in Flexible Pavement

Abstract

Flexible pavement comprises multiple layers, with a soil subgrade layer at the bottom that aids in distributing the load exerted on the upper layers of the pavement. If not properly compacted and treated, this layer might fail during its service life. Implementing appropriate measures can assist maintain its durability. This study aims to assess the effects of lime and ground granulated blast furnace slag (GGBS) on soil stabilisation. With emphasis on cost and environmental effect, this study examined how lime and GGBS strengthen soil for road building. The primary scope of this study encompasses conducting laboratory experiments to analyse the effects of lime and GGBS on soil properties, as well as utilising IITPave software to compute critical strains within a flexible pavement structure based on layered-elastic theory. The initial study includes analysing the parameters of the soil, lime, and GGBS, and testing several combinations for compaction and the California Bearing Ratio (CBR). Low, medium, and high traffic levels (20, 50, and 100 million standard axles, or MSA) were taken into consideration while designing the pavement. The findings demonstrated that higher concentrations of GGBS and lime strengthened the soil, allowing for thinner pavement layers. It was observed from this study that the most economical solution for 20 MSA traffic was a blend of 10% GGBS and 1% lime. 10% GGBS and 3% lime worked best for 50 and 100 MSA traffic. In terms of environmental performance, mixes with a 3% lime content and 10% GGBS always emitted the least amount of carbon dioxide under all conditions of traffic loading. Environmental and cost aspects were combined to prioritize pavement mixes. Based on these results, it is clear that, in flexible pavement construction, the use of 3% lime and 10% GGBS is most efficient from both environmental and economic perspectives.