1,720,974 research outputs found
Short term effects on microstructure of a compacted Kaolin clay induced by lime addition
No full textMechanical behaviour of two lime stabilised pyroclastic soils
No full textNatural pozzolanas are very reactive with calcium oxide (CaO) provided by lime, the effectiveness of the stabilisation mainly depending on the amount of stable products created in the high
alkali solution. Nevertheless, systematic studies on the suitability of pyroclastic soils to lime stabilisation
and the effects of the treatment parameters on the engineering properties of the stabilised material are still limited. In the paper some results of a large experimental study allow an overview on the suitability and the effectiveness of lime stabilisation of pyroclastic soils. Although for these soils the clay fraction is
lower than that typical of the soils commonly treated with lime, it has been found that the addition of lime improves relevantly their mechanical behaviour, increasing shear strength and reducing the one dimensional compressibility
Mechanical properties of two lime stabilized pyroclastic soils
No full textNatural pozzolanas are very reactive with calcium oxide provided by lime, the effectiveness of the stabilisation mainly depending on the amount of low alkali alluminosilicate glass phase. Nevertheless little systematic research has been conducted on the suitability of pyroclastic soils to lime stabilisation, and the effects of the treatment parameters on the engineering properties of the stabilised material. In the paper some results of a large experimental research on lime stabilisation of pyroclastic soils are presented. Two pyroclastic soils have been considered in this study. The first is a sand with gravel belonging to a pyroclastic flow deposit of the Colli Albani volcanic complex, and the second is a silty sand originated by the late activity of the Somma-Vesuvius. The results on natural and lime stabilised samples allow an overview on the suitability and the effectiveness of lime stabilisation of pyroclastic soils
Tensiocone: A cone penetrometer with the facility to measure negative pore-water pressure
No full textCPT sounding initially passes through the vadose zone, that is the zone above the phreatic surface where pore-water pressure is negative and degree of saturation is usually lower than unity. Negative pore-water pressure (suction) significantly affects tip resistance and sleeve friction and lack of knowledge of soil suction in this zone makes CPT data difficult if not impossible to interpret. For the case of Piezocone Cone Penetration Test (CPTU), crossing the vadose zone also exposes the cone tip porous filter to desaturation jeop-ardising the measurement of positive pore-water pressure once the cone penetrates the saturated zone below the phreatic surface. This paper presents the concept of the Tensiocone, a cone penetrometer with the facility to measure pore-water pressure in both negative and positive range. A first prototype was tested in the laboratory and in the field to investigate one of the major challenges in Tensiocone measurement, that is whether adequate contact can be established between the ground and the tensiometer porous filter during penetration
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