Experimental Study of the Valorization of Sulfate Soils for Use as Construction Material

Abstract

This article shows an experimental investigation carried out for the stabilization of a sulfate soil. The stabilization was carried out in two phases: the first phase was the consumption of the sulfate present in the soil through its controlled transformation into ettringite. After this, a modified soil with lower maximum density, greater optimum moisture identified via standard proctor (SP) test, no plasticity and improved unconfined compressive strength (UCS) was obtained. In the second phase, the modified soil was stabilized by the use of different additives rich in oxides of calcium or magnesium, combined with by-products or waste materials containing reactive aluminum or silicon oxides. As a result, the mechanical strength of the modified soil was improved. In this phase, a binary binder composed of a magnesium oxide product and ground granulated blast-furnace slags (GGBS) obtained the highest UCS. The binary binder composed of lime and an alumina filler formed ettringite in the treated soil. This experiment allowed for the validation of a two-phase stabilization process and the non-conventional additives used, mainly magnesium oxide and GGBS, even for high-bearing-requirement pavement layers’ construction.

Strengthening mechanisms of clay building materials by starch

“…Earth-based building materials can be described as natural concrete, composed of aggregates, such as sand or gravel, and a binder, clay minerals [7,8]. To be used in a more standardized way, industries and researchers are interested in stabilizing earth-based building materials to increase their mechanical strength and durability [9][10][11][12][13][14].…”

Sustainable Application of Wool-Banana Bio-Composite Waste Material in Geotechnical Engineering for Enhancement of Elastoplastic Strain and Resilience of Subgrade Expansive Clays

“…The extensive use of waste fibers has diverted the huge volumes of waste materials from landfill to construction projects for real benefits in the construction industry [8]. Past studies show that industrial waste materials are extensively used in stabilization of expansive Sustainability 2022, 14, 13215 2 of 14 soils for enhancement of compressive strength and reduction in swell potential [9][10][11][12][13]. Cement, lime, and fibers have been used in small to large projects for the last few decades as feasible stabilizers for the remediation of soft clays [14][15][16].…”