Clayey soils in Syria cover a total area of more than 20,000 km2 of the country, most of which are located in the southwestern region. In many places of the country, the clayey soils caused severe damage to infrastruc...Clayey soils in Syria cover a total area of more than 20,000 km2 of the country, most of which are located in the southwestern region. In many places of the country, the clayey soils caused severe damage to infrastructures. Extensive studies have been carried out on the stabilization of clayey soils using lime. Syria is rich in both lime and natural pozzolana. However, few works have been conducted to investigate the influence of adding natural pozzolana on the geotechnical properties of lime-treated clayey soils. The aim of this paper is to understand the effect of adding natural pozzolana on some geotechnical properties of lime-stabilized clayey soils. Natural pozzolana and lime are added to soil within the range of 0%–20% and 0%–8%, respectively. Consistency, compaction, California bearing ratio （CBR） and linear shrinkage properties are particularly investigated. The test results show that the investigated properties of lime-treated clayey soils can be considerably enhanced when the natural pozzolana is added as a stabilizing agent. Analysis results of scanning electron microscopy （SEM） and energy-dispersive X-ray spectroscopy （EDX） show significant changes in the microstructure of the treated clayey soil. A better flocculation of clayey particles and further formation of cementing materials in the natural pozzolana-lime-treated clayey soil are clearly observed.展开更多
Micromechanical and tribological studies of geological materials with a particular focus on their contact-mechanics behavior at the grain scale are currently a major interest in the engineering and geoscience discipli...Micromechanical and tribological studies of geological materials with a particular focus on their contact-mechanics behavior at the grain scale are currently a major interest in the engineering and geoscience disciplines. In this study, a new robust micromechanical apparatus developed at the City University of Hong Kong is described;it is capable of conducting inter-granule(or inter-particle) loading tests on fine gravel to ballast-sized materials of sizes as small as 5-10 mm to granules(or ballast) as big as 50 mm. The focus of our study is the description of the major technical features of the new apparatus and its performance and repeatability in conducting experiments on reference grains of chrome steel balls and glass balls;in addition, we conducted a preliminary set of experiments on crushed granitic rock, which is a material widely used in geotechnical and transportation infrastructure. The representative results of these experiments are presented in terms of the normal force-displacement relationship, friction, and tangential stiffness. The newly developed large-size apparatus is further compared with a well-established apparatus that can conduct micromechanical tests on sand-sized materials.展开更多
基金financial support of this research from Damascus University
文摘Clayey soils in Syria cover a total area of more than 20,000 km2 of the country, most of which are located in the southwestern region. In many places of the country, the clayey soils caused severe damage to infrastructures. Extensive studies have been carried out on the stabilization of clayey soils using lime. Syria is rich in both lime and natural pozzolana. However, few works have been conducted to investigate the influence of adding natural pozzolana on the geotechnical properties of lime-treated clayey soils. The aim of this paper is to understand the effect of adding natural pozzolana on some geotechnical properties of lime-stabilized clayey soils. Natural pozzolana and lime are added to soil within the range of 0%–20% and 0%–8%, respectively. Consistency, compaction, California bearing ratio （CBR） and linear shrinkage properties are particularly investigated. The test results show that the investigated properties of lime-treated clayey soils can be considerably enhanced when the natural pozzolana is added as a stabilizing agent. Analysis results of scanning electron microscopy （SEM） and energy-dispersive X-ray spectroscopy （EDX） show significant changes in the microstructure of the treated clayey soil. A better flocculation of clayey particles and further formation of cementing materials in the natural pozzolana-lime-treated clayey soil are clearly observed.
基金fully supported by a grant from the Research Grants Council of the Hong Kong Special Administrative Region,China(Theme-based research project Scheme “Understanding Debris Flow Mechanisms and Mitigating Risks for a Sustainable Hong Kong”-Project No.T22-603/15 N(City U 8779012))
文摘Micromechanical and tribological studies of geological materials with a particular focus on their contact-mechanics behavior at the grain scale are currently a major interest in the engineering and geoscience disciplines. In this study, a new robust micromechanical apparatus developed at the City University of Hong Kong is described;it is capable of conducting inter-granule(or inter-particle) loading tests on fine gravel to ballast-sized materials of sizes as small as 5-10 mm to granules(or ballast) as big as 50 mm. The focus of our study is the description of the major technical features of the new apparatus and its performance and repeatability in conducting experiments on reference grains of chrome steel balls and glass balls;in addition, we conducted a preliminary set of experiments on crushed granitic rock, which is a material widely used in geotechnical and transportation infrastructure. The representative results of these experiments are presented in terms of the normal force-displacement relationship, friction, and tangential stiffness. The newly developed large-size apparatus is further compared with a well-established apparatus that can conduct micromechanical tests on sand-sized materials.
