Determinationofelasticmodulus of claystone:Nano-/micro-indentation andmeso-compression tests used to investigate impact of alkaline fluid propagation over 18 years  

作　　者：Danièle Bartier Christophe Auvray 

机构地区：[1]GeoRessources, UMR 7359, Université de Lorraine, CNRS, CREGU, Campus Aiguillettes, Vandoeuvre-les-Nancy, 54500, France

出　　处：《Journal of Rock Mechanics and Geotechnical Engineering》2017年第3期129-136,共8页岩石力学与岩土工程学报（英文版）

基　　金：GNR NEEDS-MIPOR for funding this project

摘　　要：Micro-mechanical properties of a claystone were tested after undergoing alkaline perturbation on site(Tournemire,CD borehole)for 18 years.In a saturated context and outside the excavation disturbed zone(EDZ),the claystone exhibits a 11.6-mm black rim at the cement/paste interface,which shows a different mechanical behaviour from the rest of the claystone.Three sets of measurements of elastic modulus were performed using:(i)nano-indentation tests with a constant indentation depth of 2 mm,(ii)microindentation tests with a constant indentation depth of 20 mm,and(iii)meso-compression tests with a constant displacement of 200 mm.The increase of the modulus of deformability in the black rim is between 15 GPa and 20 GPa according to the scale.Moreover,an overall decrease of the modulus of deformability from the smallest to the largest scale is observed in each zone.In view of the mineralogy and petrographic observations,higher values of modulus of deformability in the black rim are related to carbonate content and its distribution.Precipitation of cementitious carbonates as inclusions and very thin partings leads to hardening of the claystone.Micro-mechanical properties of a claystone were tested after undergoing alkaline perturbation on site(Tournemire,CD borehole)for 18 years.In a saturated context and outside the excavation disturbed zone(EDZ),the claystone exhibits a 11.6-mm black rim at the cement/paste interface,which shows a different mechanical behaviour from the rest of the claystone.Three sets of measurements of elastic modulus were performed using:(i)nano-indentation tests with a constant indentation depth of 2 mm,(ii)microindentation tests with a constant indentation depth of 20 mm,and(iii)meso-compression tests with a constant displacement of 200 mm.The increase of the modulus of deformability in the black rim is between 15 GPa and 20 GPa according to the scale.Moreover,an overall decrease of the modulus of deformability from the smallest to the largest scale is observed in each zone.In view of the mineralogy and petrographic observations,higher values of modulus of deformability in the black rim are related to carbonate content and its distribution.Precipitation of cementitious carbonates as inclusions and very thin partings leads to hardening of the claystone.

关 键 词：Claystone Elastic modulus Nano-indentation MICRO-INDENTATION Meso-compression Carbonate Claystone/cement paste contact 

分 类 号：TU45[建筑科学—岩土工程]