Search results for "Clay"
showing 10 items of 349 documents
Hydro-mechanical behaviour of shot-clay bentonite
2015
Experimental tests were conducted to characterise the hydro-mechanical behaviour of shot-clay MX-80 bentonite. Granular bentonite was mixed continuously with water and shot on the walls of a tunnel section at the Grimsel Underground Research Laboratory (URL), in Switzerland. The shot-clay was placed to create a layer of bentonite in direct contact with the host rock to avoid preferential water and/or gas flow along the tunnel wall. Samples for an experimental programme were collected during the shooting. Results from an experiment, conducted under controlled total suction to analyse the hydro-mechanical behaviour of the material, are shown.
The role of pedogenic overprinting in the obliteration of parent material in some polygenetic landscapes of Sicily (Italy)
2016
Abstract Many soils older than the Holocene have experienced several changes, and possess properties that may be due to the complex effect of several stages of soil development; these soils are called polygenetic. It is still rather unclear, however, if, as time elapses, pedogenic processes tend to diverge generating different soils, or converge towards increasingly similar soils. We studied five pedons (37°60′N, 13°90′E) exposed to present weathering simultaneously since the Holocene but located on Upper Miocene or Holocene parent material. Their XRD and FTIR clay mineralogy reveal an overall homogeneity; smectites, calcite and gypsum reach the thermodynamic equilibrium, a slight undersatu…
Modelling the Water Retention Domain of a Compacted Scaly Clay
2012
A body of experimental data on the water retention behaviour of compacted samples of an Italian scaly clay is analysed. The mechanical and the hydraulic behaviour of compacted samples of this clay are governed by multi-scale arrangement of scales and aggregates, which characterises the compacted clay fabric. At least two different pore networks, namely intra-aggregate and inter-aggregate, may be identified, which interact one with the other along coupled hydro-mechanical paths. The retention behaviour is interpreted in the framework of a comprehensive multi-scale modelling approach recently proposed for compacted clays of low and medium activity, which proves to be able to account for the i…
Shear Strength of a Compacted Scaly Clay from Suction-Controlled Triaxial Tests
2012
The paper presents the results of an experimental research aimed at investigating the shear strength characteristics of an unsaturated compacted scaly clay. Shear strength was investigated by suction-controlled triaxial compression tests on dynamically compacted samples. Collected results point out that suction effects on stiffness and shear strength can be very different for suction values applied lower or greater than air entry value (AEV), corresponding to the material void ratio.
CHLORITE/SMECTITE - ALKALI FELDSPAR METASOMATIC XENOLITHS FROM HYBLEAN MIOCENIC DIATREMES (SICILY, ITALY): EVIDENCE FOR EARLY INTERACTION BETWEEN HYD…
2006
Upper-Miocene tuff-breccia pipes from the Hyblean area (south-eastern Sicily) bear a number of ultramafic and mafic xenoliths (spinel-peridotites, pyroxenites, gabbroic rocks) whose study has led to conclude that the Meso-Caenozoic carbonatic and volcanic succession stands upon a fossil oceanic core-complex, probably connected with the adjacent Ionian crust. Evidence for hydrothermal metasomatism is common in the Hyblean ultramafic and mafic xenoliths. In some cases, extreme metasomatic transformation and shearing have deleted original mineralogy and textures yielding unusual rocks, hereafter called “metasomatites”. These rocks generally exhibit cataclastic texture, their hydrothermal miner…
Thermo-mechanical volume change behaviour of Opalinus Clay
2016
The paper examines the thermo-mechanical volume change behaviour of Opalinus Clay in relation to different stress conditions and overconsolidation ratio (OCR) values and evaluates the impact of temperature on some hydro-mechanical properties of this material. To this aim, a focused experimental campaign consisting in high-temperature/high-pressure oedometric tests has been carried out. The results show that the thermo-mechanical volume change behaviour of Opalinus Clay is heavily affected by the OCR: thermal expansion is found when the heating is carried out at high OCR, whereas irreversible thermal compaction is observed when heat is applied at a vertical effective stress that is sufficien…
Signatures terrigène et volcanique des bassins sédimentaires : implications stratigraphiques et paléoclimatiques
2018
Interaction between armenian-clay-based ceramics and model wines
2022
The use of ceramics for the transformation or conservation of wine has existed since the origins of wine, but the impact of ceramics on wine has not received much attention.However, in contact with the wine, ceramics are generally not neutral materials and the constituent minerals of ceramics are led to dissolve. This work mainly aims to study the migration of elements from ceramics to wine.To our knowledge, this question has so not been addressed so far, at least with our chosen approach.This study required the prior characterization of the materials and the ceramics produced in the laboratory.The analyzes (XRF, XRD, and SEM/EDX) revealed that the natural material used for the manufacture …
Etude de la variabilité des propriétés physiques et hydrodynamiques d'un sol argileux sous l'effet de conduites en protection intégrée contre les adv…
2015
Integrated weed management (IWM)-based cropping systems are of great interest due to their significant reduction of herbicide inputs by using a complex combination of agricultural techniques. The main objective of our work was to contribute to the environmental dimension of the multi-criteria evaluation of IWM-based cropping systems which were set up since 2000 on the experimental domain of the National Institute for Agronomical Research (INRA) to Bretenière (France). The variability of physical and hydrodynamic soil properties involved in the transfer of water through the vadose zone was studied for the 5 cropping systems present on the experimental site (1 reference cropping system and 4 …
Sevrey (Saône-et-Loire). 8 rue Georges Brusson [notice archéologique]
2019
La fouille préventive, réalisée au 8 rue Georges Brusson à Sevrey, sur une superficie d’environ 300 m2 apporte de nouveaux éléments concernant la production potière dans ce secteur du Val de Saône. La densité et la qualité des vestiges sont tout à fait remarquables. L’étude est toujours en cours, mais il est d’ores et déjà possible de présenter les grands traits caractéristiques des occupations successives.