Effect of Soil Stabilization Using Ground Granulated Blast Furnace Slag and Alkali Activated Solutions on Rigid Pavement Cost

This paper examines how stabilizing road subgrade soils with ground granulated blast furnace slag (GGBFS) and alkali-activated solution (AAS) influences both rigid pavement layer thicknesses and initial investment expenditures. For this investigation, bentonite (BT) samples representing the subgrade soil were blended with GGBFS and AAS solutions formulated with 8 molar sodium hydroxide at weight percentages of 5%, 10%, 15%, and 20%. Proctor and unconfined compressive strength (UCS) trials were carried out on the prepared formulations. Following a 28-day curing stage, the maximum compressive strength performance was observed in the 10% GGBFS+AAS blends. California Bearing Ratio (CBR) assessments conducted on the control soil versus the optimum 10% GGBFS+AAS mixture indicated an 11.80 fold enhancement in the CBR performance of the modified soil. Based on structural designs and economic evaluations performed in compliance with AASHTO 1993 guidelines, the results demonstrate that ground stabilization using 10% GGBFS+AAS optimizes concrete pavement layer configurations, yielding a 1.42% reduction in initial construction costs.