IN-SITU INTERACTION OF CEMENT PASTE AND SHOTCRETE WITH CLAYSTONES IN A DEEP DISPOSAL CONTEXT
IN-SITU INTERACTION OF CEMENT PASTE AND SHOTCRETE WITH CLAYSTONES IN A DEEP DISPOSAL CONTEXT
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DOI：
10.2475/03.2012.03
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发表时间：
2012-03-01
影响因子：
2.9
通讯作者：
Claret, F.
中科院分区：
文献类型：
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作者：
Gaboreau, S.;Lerouge, C.;Claret, F.
在Andra Meuse/Haute马恩（法国）地下研究实验室（URL）进行了现场取样，以研究两种水泥基材料/粘土岩界面，这些界面已经经历了4至5年的相互作用。第一个界面涉及在实验室水平喷射到通道巷道壁上的喷射混凝土，第二个界面涉及从地面注入钻孔并在新巷道挖掘期间拦截的G级水泥浆。在第一种情况下，水动力条件由巷道通风控制;在第二种情况下，水泥浆和粘土岩材料被认为是饱和的，远离任何机械扰动。因此，在纳米到厘米尺度上对接触的不同材料进行化学、矿物学和纹理测量。结果表明，胶结物和粘土岩之间的地球化学对比所引起的扰动在界面两侧均限于μ m尺度。根据水动力条件和水泥材料的配方，在水泥材料中观察到碳酸化，导致孔隙开口或堵塞。的阳离子交换人口的分布也被修改的粘土岩接触的水泥浆，其中确定的可交换部分的钾饱和。本工作的独创性是，现实的现场控制样品从安德拉URL进行了研究，从而允许评估的影响自然的不均匀性的原位实验条件（即，水动力条件，工程损坏区，矿物学的变化）的扰动在水泥浆/粘土岩界面。一个重要的结果是孔隙堵塞沿界面沿着是不均匀的。
In-situ sampling was performed in the Andra Meuse/Haute Marne (France) Underground Research Laboratory (URL) allowing the study of two cement based materials/claystone interfaces that have undergone 4 to 5 years of interaction. The first interface concerned a shotcrete that was sprayed on the wall of an access drift at the laboratory level and the second one, a class G cement paste that was injected in a borehole filled from the surface and was intercepted during the excavation of a new gallery. In the first case, the hydrodynamic conditions were controlled by the ventilation of the drift; while in the second, the cement paste and claystone materials were considered saturated and far from any mechanical perturbation.A multi scale investigation was carried out to identify any evidence of alkaline perturbation in the cement based materials and the claystone. Chemical, mineralogical, and textural measurements were thus performed on the different materials in contact at the nanometer to a centimeter scale. Results showed that all the perturbations resulting from the geochemical contrast between the cement materials and the claystone were limited to a mu m scale on each side of the interfaces. Carbonation was observed in the cement materials leading to an opening or a clogging of the porosity according to the hydrodynamic conditions and the formulation of the cement material. The distribution of the cation exchange population was also modified in the claystone in contact with the cement paste where a potassium saturation of the exchangeable fraction was identified. The originality of the present work is that realistic field controlled samples from the Andra URL were studied, hereby allowing the evaluation of the impact of natural heterogeneities of the in-situ experimental conditions (that is, hydrodynamic conditions, engineered damage zone, mineralogical variations) on the perturbations at the cement paste/claystone interfaces. An important result is that the clogging of porosity was not homogenous along the interfaces.