Assessing the Use of Cement Kiln Dust to Stabilize Sandy Soils for Subgrade Construction

Abstract

Sandy soils are characterized by their high porosity and loose particle size making them highly susceptible to erosion posing significant challenges in various construction applications. This research explores the viability of utilizing cement kiln dust which is an industrial by-product from cement manufacturing as a sustainable alternative for stabilizing sandy soils. CKD is rich in Calcium Oxide and Silica, thereby offering potential pozzolanic properties that could enhance soil cohesion and mechanical performance while addressing waste management challenges associated with its disposal. This study evaluates the geotechnical properties of CKD-stabilized sand soils through a series of laboratory experiments including Proctor test, Unconfined Compressive Strength (UCS), California Bearing Ratio test and permeability tests. Different percentages of cement kiln dust ranging from 5% to 20% by weight were mixed with the sandy soil samples to determine the optimal percentage for maximizing strength and durability. The optimum percentage of cement kiln dust to be added was observed to be 15% since the results obtained demonstrated a 45% improvement in UCS and a 58.5% improvement CBR values after a 7-day curing period. Additionally, the permeability greatly decreased by 93% indicating enhanced soil stability and reduced erosion potential. The shrinkage characteristics of the soil that is PI, CBR swell and linear shrinkage were all found to be within the acceptable limits according to the MoWT general specifications for Road and Bridge Works 2005.