Strength and compressibility characteristics of problematic soils such as loose sands and extra-sensitive clays need to be enhanced for the construction purposes which is due in part to the population growth and society’s ever-expanding requirements. Accordingly, cemented soils are being used as a world-renowned soil stabilization practice in all geotechnical engineering applications, yet the high energy consumption and cost of cement is to blame. Therefore, various types of binders have been proposed to partially or even totally supplant the cement, whilst fibers have emerged to be used as composite reinforcement. The current study provides a simple literature review on cemented composites, common non-conventional stabilizers, reinforcing fibrous inclusions and the simultaneous use of a stabilizer and a reinforcing agent. It encapsulates highlighted studies which are stated in a logical sequence to introduce the most practical mixtures used for the stabilization purposes. Moreover, microstructural analysis and measurements regarding variable properties of mortar-like and cemented granules composites will be discussed. Eventually, future works such as an appropriate use of weight–volume relationships as well as adopting an objective qualitative assessment for the selection of the additives will be recommended.

A Simple Review of Cemented Non-conventional Materials: Soil Composites

This research investigates the effect of Lignosulfonate (LS), timber and paper industries by-product, in improving physical and geotechnical properties of high plasticity clay from the Amol city in the Mazandaran province, Iran. Long-term behavior of unstabilized and LS-stabilized clay by using direct shear tests were evaluated. In addition, the effect of wetting and drying cycles on the results of direct shear and unconsolidated-undrained (UU) triaxial tests was investigated and compared together. Addition of LS by aggregation of clay particles, enhanced the physical and strength properties of the clay. The effect of LS-stabilization on the internal friction angle of the soil was negligible (only one degree increase). The major part of the improvement in long-term strength of the soil, was due to increased cohesion between soil particles (from 1 to 7 kPa). Also, test results revealed that wetting and drying cycles has no considerable effect on the UU triaxial test results (up to 1.86% decrease in maximum deviatoric stress). However, in the direct shear tests, the samples are more affected by wetting and drying cycles (up to 37% decrease in peak shear strength). Scanning electron microscopy (SEM) micrographs revealed that due to the stabilization, the structure of clay was changed from a particle base to an aggregated form. In fact, in this case, the pores in the soil structure have been reduced, which has led to strength increase.

Physical and geotechnical long-term properties of lignosulfonate-stabilized clay: An experimental investigation

Calcium-carbide residue (CCR) was used as a precursor to synthesise CaO–Al2O3–SiO2–CaSO4 heterogeneous acid catalyst for biodiesel production. The synthesis was through a two-step process of thermal treatment of the CCR at 500, 700, and 900 °C and sulphonation, to produce anhydrite-based solid-acid catalysts (ASACs) as ASAC500, ASAC700, and ASAC900 respectively. The CCR and ASACs were characterised using X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Brunauer–Emmet–Teller (BET). The ASACs were tested for biodiesel production using high free fatty acid waste lard. The XRD analyses show that the three catalysts consist of CaSO4 in addition to each containing Ca2.62Al9.8Si26.2O72H4.56 (ASAC500), carbon atom and Ca2.62Al9.8Si26.2O72H4.56 (ASAC700), Ca2.62Al9.8Si26.2O72H4.56 and Ca2Al4Si14O36•14H2O (ASAC900). The SEM images of the ASACs show the formation of different surface morphology with active sites and improved porosity based on calcination temperatures. The BET analysis presents a surface area of 94.48 (ASAC500), 90.28 (ASAC700), and 98.22 m2/g (ASAC900). The biodiesel yields obtained using 5% (w/w) catalyst, 12:1 of MeOH: Lard molar ratio, 120 min reaction time and 60 °C reaction temperature are 94.8% (ASAC500), 89.2% (ASAC700) and 98.9% (ASAC900). The excellent performance of CaO–Al2O3–SiO2–CaSO4 catalyst with the high yields of biodiesel and recyclability of seven cycles are attributed to the synergy among the calcium, aluminium, and silicon. Therefore, the CCR is a suitable precursor to synthesise a novel heterogeneous acid catalyst that is highly effective for biodiesel production.

Calcium-carbide residue: A precursor for the synthesis of CaO–Al2O3–SiO2–CaSO4 solid acid catalyst for biodiesel production using waste lard

Effect of TIPA on mechanical properties and hydration properties of cement-lithium slag system.

An evaluation of the performance of hot mix asphalt containing calcium carbide residue as a filler

Increased use of industrial residues for soil stabilization is a necessary practice for sustainable geotechnics. The present study investigates carbide lime, the residue resulting from the ...

José Eduardo Corrêa Mallmann

Papers

Physical–Mineralogical–Chemical Characterization of Carbide Lime: An Environment-Friendly Chemical Additive for Soil Stabilization

Enhancement of strength of coal fly ash–carbide lime blends through chemical and mechanical activation