Mechanical properties of soil reinforced with both lime and four kinds of fiber

This study intended to address the problem of damaged (collapsed, cracked and decreased soil strength) road pavement structure built on clay soil due to clay soil properties such as low shear strength, high soil compressibility, low soil permeability, low soil strength, and high soil plasticity. Previous research reported that ground granulated blast slag (GGBS) and fly ash can be used for clay soil stabilizations, but the results of past research indicate that the road pavement construction standards remained unfulfilled, especially in terms of clay’s subgrade soil. Due to this reason, this study is carried out to further investigate soil stabilization using GGBS and fly ash-based geopolymer processes. This study investigates the effects of GGBS and ratios of fly ash (solid) to alkaline activator (liquid) of 1:1, 1.5:1, 2:1, 2.5:1, and 3:1, cured for 1 and 7 days. The molarity of sodium hydroxide (NaOH) and the ratio of sodium silicate (Na2SiO3) to sodium hydroxide (NaOH) was fixed at 10 molar and 2.0 weight ratio. The mechanical properties of the soil stabilization based geopolymer process were tested using an unconfined compression test, while the characterization of soil stabilization was investigated using the plastic limit test, liquid limit test, scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). The results showed that the highest strength obtained was 3.15 MPA with a GGBS to alkaline activator ratio of 1.5 and Na2SiO3 to NaOH ratio of 2.0 at 7 days curing time. These findings are useful in enhancing knowledge in the field of soil stabilization-based geopolymer, especially for applications in pavement construction. In addition, it can be used as a reference for academicians, civil engineers, and geotechnical engineers.

Evaluation on the Mechanical Properties of Ground Granulated Blast Slag (GGBS) and Fly Ash Stabilized Soil via Geopolymer Process

Geopolymers, or also known as alkali-activated binders, have recently emerged as a viable alternative to conventional binders (cement) for soil stabilization. Geopolymers employ alkaline activation of industrial waste to create cementitious products inside treated soils, increasing the clayey soils’ mechanical and physical qualities. This paper aims to review the utilization of fly ash and ground granulated blast furnace slag (GGBFS)-based geopolymers for soil stabilization by enhancing strength. Previous research only used one type of precursor: fly ash or GGBFS, but the strength value obtained did not meet the ASTM D 4609 (<0.8 Mpa) standard required for soil-stabilizing criteria of road construction applications. This current research focused on the combination of two types of precursors, which are fly ash and GGBFS. The findings of an unconfined compressive strength (UCS) test on stabilized soil samples were discussed. Finally, the paper concludes that GGBFS and fly-ash-based geo-polymers for soil stabilization techniques can be successfully used as a binder for soil stabilization. However, additional research is required to meet the requirement of ASTM D 4609 standard in road construction applications, particularly in subgrade layers.

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Potential of Soil Stabilization Using Ground Granulated Blast Furnace Slag (GGBFS) and Fly Ash via Geopolymerization Method: A Review

Recycling of paper/wood industry waste for hydromechanical stability of expansive soils: A novel approach

In this research work, the effect of various independent operating variables on the removal of malathion pesticide by electrocoagulation (EC) process was evaluated by single variable multivariable optimization. The various operating variables selected were reaction time (40–75 min), pH (6−9), applied voltage (8–20 V), and amount of electrolyte (8–20 ml). The effect of aluminium and iron electrode on the removal efficiency were compared and aluminium was found to be better performed, further RSM studies were carried out with this electrode. The optimum operational conditions were achieved as reaction time of 75 min, solution pH of 7.5, applied voltage of 15 V and the electrolyte addition of 15 ml. A removal efficiency of 85% was obtained at an energy consumption of kWh. by incorporating the interaction effects of different optimized variables. In this paper, the facts associated with the removal mechanism and the operational cost analyses were performed. The reaction behaviour has been discussed through mini reaction pathways and results were supported by SEM, EDAX and FTIR characterizations. End products of the EC process are the dissociated pesticide with metal hydroxide particles. This study also discusses the disposal of solid sludge with economic and environmental benefits used as admixture in the stabilization of expansive soils. The sludge fused soil properties were improved when compared to the plain soil properties and the classification of soil were changed from moderate to stiff soil. This indicates the possible use of sludge as stabilizing agent subsequently and it can address the disposal and environment concern related to the end products of EC process in economic way.Effect of this soil on the ground water pollution was also investigated.

Optimization and evaluation of malathion removal by electrocoagulation process and sludge management

The cyclic heave and settlement of expansive soils could be the main reason to considerable damages to the structures, roads and highways. In Egypt there are many regions containing such expansive soils especially at the desert lands. The remote areas are used now for establishing many projects such as (wind farms, solar plants, irrigation projects and nuclear power plants). The use of a mixture of lime-treated swelling soil mixed with potable water to overcome the swelling potential of these soils is available in many countries especially in U.S.A. For the projects located adjacent to the coasts of Sea, the sea water is available instead of potable water. This paper presents an experimental and field case study on the lime-treated soil but mixed with sea water instead of potable water. The effect of using sea water instead of potable water on the swelling behavior, engineering properties, and the consolidation parameters were studied. On the other hand, this research deals with the behavior of the lime-treated soil in swelling state as well as in consolidation state. Tests results showed that there are significant reductions in the swelling potential, engineering properties, and the consolidation parameters in case of using sea water instead of potable water as mixing water. The environmental and economic impact gained from such process was put into consideration.

Swelling soils treatment using lime and sea water for roads construction

A numerical study of anchored sheet piles subjected to different types of sandy soils backfill

The paper studied a case of anchored sheet piles that exposed to surcharge loads at different distances from the wall. Experimental works were conducted on two different systems of single and double anchored sheet pile walls. Also, numerical simulations were performed on both systems using PLAXIS. The experimental and numerical results were compared. The comparison showed the advantages of using double anchored sheet pile instead of single anchored one. It was found that a large reduction occurred in the values of maximum bending moments in the double anchored system, in addition to a significant reduction in the values of anchor forces. This paper also produced three simplified approaches aiming to solve the statically indeterminate system of double anchored sheet pile exposed to surcharge loads placed at different distances from the sheet pile wall.

https://jesaun.journals.ekb.eg/article_117622_1fba348d7a8a6ff6a5b32305238ee5f5.pdf

Safwat A. Seleem

Papers

Swelling soils treatment using lime and sea water for roads construction

A numerical study of anchored sheet piles subjected to different types of sandy soils backfill

Comparison between single and double anchored sheet piles with simplified approaches to solve the statically indeterminate systems