Utilization of GGBS as a sustainable cement replacement in soil-cement columns: enhancing ground stabilization through industrial waste

Introduction. A soil-cement composite, comprising a thoroughly blended mix of soil, cement, and water, has played a crucial role in the construction of various civil infrastructures like bridge foundations, tunnels, highway embankments, foundations for port and harbour structures, and many more. Though efficient, traditional high-cement formulations pose severe environmental concerns, leading to the exploration of alternative materials that can bring sustainability to construction practices.

Materials and methods. This study focuses on utilizing “Ground-Granulated Blast-Furnace Slag” (GGBS) to explore its impact on the engineering characteristics of soil-cement mixtures. In this investigation, clay soil is blended with 20 % of OPC and varying proportions of GGBS (20, 25 and 30 % by weight of cement) as a replacement for OPC.

Results. The composite mixture is subjected to several Unconfined Compressive Strength (UCS) tests to assess the undrained shear strength of soil-cement-GGBS mixtures at distinct curing intervals (7, 14, and 28 days). Field emission scanning electron microscopy (FE-SEM) is also employed to examine the microstructure of the soil-cement composite, revealing the arrangement of particles, pore structures, and the distribution of cementitious materials.

Conclusions. The results show that the composition having clay soil and 20 % cement, replaced with 20 % GGBS, yields maximum strength among all tested compositions with a significant increase of 24 % compared to the conventional soil-cement mixture of clay soil and 20 % cement only.

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