A review of polyurethane as a ground improvement method

Ground improvement based on lightweight materials is commonly applied as a method to overcome the problem related to excessive and differential settlement. The application of polyurethane (PU) as a ground improvement work currently increases in demand due to its well performance in many ground improvement projects. The properties and strength of different types of PU available in the market, together with the safety issues and precautions are highlighted in this paper. Due to its lightweight properties, buoyancy behavior of the lightweight foam often causes uplift which jeopardize the stability of the existing structure. Since it is applied in the ground, awareness on PU degradation needs to be emphasized. The suitability and applications of PU as one of alternative method for ground improvement works are also highlighted in this paper

Utilization of kenaf core fiber – marine clay mixture as a landfill liner material

Nowadays, leachate production is a big concern and causes a serious hazard to the soil and groundwater which causes the subsurface soil to be polluted as a result of the loss of soil quality and environmental pollution. This study aims to study the potential of using kenaf core fiber and marine clay mixtures as improved landfill liner material. Relevant laboratory tests such as atterberg limit test, specific gravity test, and particle size distribution were performed to examine basic geotechnical properties of marine clay soil collected from Batu Kawan, Penang. Besides that, compaction test and hydraulic conductivity test were carried out for soil mixed with kenaf core fiber to determine the strength and permeability characteristics. The results found that the marine clay has significantly adequate physical properties to be used as a landfill liner. The permeability test for marine clay soil inclusion of kenaf core fibre indicated that the hydraulic conductivity of the samples admixture for 0%, 4%, 8%, and 12% ranged between 6.68 × 10-9 and 1.57 × 10-8 m/s. Compaction of marine clay mix kenaf core fibre samples resulted in maximum dry density, ρdmax that ranged between 0.936 and 1.595 g/cm3 and optimum moisture content, wopt that ranged between 19.8% and 24%. Hence the inclusion of kenaf core fiber in marine clay soil improves the maximum dry density value, decrease permeability of marine clay and could be potentially used for landfill liner material

Evaluation of climate change on the collapse potential of unsaturated cement-treated laterite soil for disaster risk reduction

Extreme weather events and intense rainfall may alter the climate, which would probably affect the geotechnical constructions such as unsaturated embankments. Basically, soil moisture content determines the strength of the unsaturated soil, with wetter soils often being weaker. Although it has been proved that unsaturated condition substantially impacts the shear strength and volumetric behaviour of soil, its implications are rarely investigated or taken into account in the design. As a result, changes in temperature and rainfall loads will have an influence on geotechnical constructions and develop long-term seasonal deformations that might severely jeopardize safety and maintenance. Therefore, it is crucial to assess the effects of the climate on soil behaviour for each location through adequate geotechnical laboratory tests. Johor, Malaysia has a large area and abundant tropical soils. Hence, this study aimed to elucidate the influence of climate change on soil behaviour in the tropical regions of Johor. To impose Malaysia's climate, a series of modified suction-controlled oedometer tests are conducted under different matric suctions. The outcomes revealed that the low and high matric suction has significantly impacted the untreated and cementtreated soil. However, the great reduction of soil settlement is mostly from the coupling effect of saturation and stabiliser

The Significant Effect of Interface Shear Strength Between Soil Liner and Geotextile with Different Percentages of Bentonite and Sodium Bentonite with Geosynthetic

This research focuses on the interface shear performance between geotextile and soil with various percentages of bentonite and sodium bentonite for landfill stability by using Direct Shear Test. Admixtures are mixed with clay to improve its performance as a liner material due to their ability to fill the voids between soil particles and also the most effective sealants. The aim of this study is focused on evaluating the effectiveness of bentonite and sodium bentonite on improving interface shear strength of fine soil. In this study, direct shear box was used to measure the interface shear strength of soil with different percentages of bentonite and sodium bentonite at optimum moisture content. Analysis shows that the most suitable percentage is of 5 % of bentonite and 2.5 % of sodium bentonite due to the highest interface shear strength of the mixture with geosynthetic. It is clearly shown that 2.5 % sodium bentonite is the most suitable percentage to be used as admixture for landfill stability as it gives higher interface shear strength

The Significant Effect of Interface Shear Strength Between Soil Liner and Geotextile with Different Percentages of Bentonite and Sodium Bentonite with Geosynthetic

This research focuses on the interface shear performance between geotextile and soil with various percentages of bentonite and sodium bentonite for landfill stability by using Direct Shear Test. Admixtures are mixed with clay to improve its performance as a liner material due to their ability to fill the voids between soil particles and also the most effective sealants. The aim of this study is focused on evaluating the effectiveness of bentonite and sodium bentonite on improving interface shear strength of fine soil. In this study, direct shear box was used to measure the interface shear strength of soil with different percentages of bentonite and sodium bentonite at optimum moisture content. Analysis shows that the most suitable percentage is of 5 % of bentonite and 2.5 % of sodium bentonite due to the highest interface shear strength of the mixture with geosynthetic. It is clearly shown that 2.5 % sodium bentonite is the most suitable percentage to be used as admixture for landfill stability as it gives higher interface shear strength