Feasibility tests on ground granulated powders compiled from waste concrete for soil solidification

Abstract

The objective of the present study is to examine the applicability of ground granulated powders (GGPs) as a cementitious binding material for soil solidification. The compressive strength gain of the GGPs was tested under alkali activation treatments using Na₂SO4 or a ground granulated blast-furnace slag (GGBS) compound containing 7.5% Ca(OH)₂, and empirically formulated through regression analysis using test data. Two types of activated GGPs with high compressive strengths were selected from the paste samples and then applied to soft cohesive soils at different binder-to-soil ratios. The sustainability of the activated GGPs was examined using the CO₂ footprint calculated for the prepared soil-solidification mixtures. Lower porosity was measured in the GGP pastes activated by the 5% GGBS compound and 30% Na₂SO₄ in comparison to the other specimens; this resulted in a higher compressive strength gain for the two pastes. Additionally, the present soil solidification mixtures exhibited higher compressive strength than ordinary Portland cement-based solidification and an equivalent strength to geopolymerized metakaolin-based solidification. The results indicate that the GGPs activated by the 5% GGBS compound demonstrate great potential as sustainable cementitious binding materials for the targeted application areas, considering their considerably lower CO₂ footprint and common compressive strength gain requirements.

Keywords:

• Ground granulated powders
• activation
• soil solidification
• CO₂
• compressive strength

Disclosure statement

The author declares that there is no conflict of interests regarding the publication of this paper.

Additional information

Funding

This work was supported by the Korea Institute of Energy Technology Evaluation and Planning (KETEP) and the Ministry of Trade, Industry & Energy (MOTIE) of the Republic of Korea (No. 20161510300420).