Abstract

Cation binding by organic matter content (OMC) in soils has consequences for the behaviour of the organic compounds themselves, influencing adsorption, aggregation, and solubility, and thereby soil structure, translocation of organic matter within soils, and transport to waters. The study reported here involved a number of experiments using composition of alkaline earth metals grout to treat organic soils, in order to provide a better understanding of the engineering behaviour of this soil after stabilization. Besides, it provides a series of the laboratory mix design and testing which in turn provide an essential guide regarding the choice, dosage and economical amount of chemical binders. We carried out a series of batch test using composition of sodium silicate system binders to find their effects on physic-chemical properties of the organic soil. The results show that in the batch tests unconfined compressive strength (UCS), increases of up to 220% of the soil’s baseline strength can be achieved by adding the 3 mol/L Na₂Sio₃, while UCS results enhanced to 270% having an activator CaCl₂ and/or Al₂(SO₄)₃ additives. Moreover, using higher molarities of CaCl₂ (for example, 1mol/L) did not show any remarkable effect on the UCS results.

Key words: Organic soil, soil improvement, cationic stabilizer, cementation, unconfined compressive strength, sodium silicate grout system.

Abbreviation

OMC, Organic matter content; UCS, unconfined compressive strength; ASTM, American Standard for Testing and Material; EDL, electrical double layer; DDL, diffuse double layer; CEC, cation exchange capacity; BS, British Standard Institution.