Pore Space investigation in natural and artificial materials: POSINAM (FP7-MC-IAPP) project (15.10.2009-14.10.2013)

Document available in extended abstract form only. Waste storage requires the analysis of various types of materials in order to measure spatial relationship and connectivity of their pores as well as quantity, shape, and size. It is necessary to describe pore space, to model fluid transport and to identify the material composition in order to understand the 3D organisation of the solids and the pores, and to stabilise the structure of this material for its observation. To characterise heterogeneous spatial porosities of these materials a saturation technique with a 14C- or 3H PMMA resin was developed at HYRL. The method includes saturation of matrices with radiolabelled un-viscous methylmethacrylate MMA, irradiation polymerisation and auto-radiographic detection of the sawn surfaces. POSINAM project has been proposed by the SME called ERM due to the increasing need of porosity characterisation of geo-materials by large industrial companies. These demands consist of research applications that will be based on the enhancement of the knowledge on altered natural rocks or materials as well as, saturation and imaging techniques for characterising the porosity of these materials. Thus, there is an essential need for a transfer of technology and knowledge between HYDRASA/HYRL labs and ERM. The combination of developed skills by private and academic partner labs along with ERM represents an innovative means to solve industrial issues on quantification of porosity in materials. The objective of the research program is to produce realistic 3D models of natural and artificial materials including porosity distribution. To achieve this goal it is necessary: To improve knowledge of petrography on rocks, cements and soils, etc. related to porosity organization (HYDRASA). To characterize heterogeneous spatial porosities of these materials using a saturation technique with 14C- or 3H doped PMMA resin. To provide service for industries which need 3D models of their materials. The fulfillment of IAPP POSINAM project includes the building of a technical platform which is now ready to be used in Poitiers University site (France). Application of radioprotection rules is needed for a proper use of radioactive resin. Contamination testing measurements are actually performed for the preparation of ASN licensing documents. A radiation safety course was given by HYRL members to ERM and HYDRASA's employees end users. Exchange of knowledge from ERM/HYDRASA to HYRL was also achieved during POSINAM project by delivering course on petrography and image analysis. scientific and technical/technological goals: To set-up polymerization by heating and determine its effect on materials. To assess the organization of resin in interlayer pore space for swelling clay, to determine the structural changes of the pore space when replacing water by polymer in interlayer space and micropores. To develop innovative and specific software for porosity imagery analyses. To normalize the methodology of saturation, polymerization and autoradiography according to quality standards needed for industrial application. To organize the development of the methodology to improve various application possibilities such as developing the pre-handling techniques for brittle and swelling clays; to introduce different markers in resin. To standardize the software used in the quantitative pore space analysis to reach similar results from one site to another. To build a platform in Poitiers for industrial use of the method where the radio labeled material as well as hazardous organic liquids can be handled, e.g. taking into account radioprotection and chemical risk. To develop in-situ and laboratory testing procedures and study their differences; to study the differences in the information provided by 14C-PMMA method using 'digital autoradiography' or an old fashioned film autoradiography. The potential impacts are the scientific and economic development of a group able answering to the demands originating from industrial companies or public bodies to characterize porosity of clay rocks/cement. Optimization of the thermal polymerization was conducted in HYRL, and was completed. In addition to earlier results, non swelling clay samples were impregnated and irradiation polymerization versus thermal polymerization was compared. The PMMA porosities for bricks were in good agreement despite of the polymerization method used. The PMMA porosities for Grimsel granodiorite were similar too. The initial results for the clay samples show fairly good agreement between the porosities done by different polymerization techniques. The characterization of transport, retardation and storage properties of geological and artificial solid mineral matrices requires investigation of the connected pore space and its relation to composition and structure of the material in the context of genetical issues of the geological evolution as well as technological issues of technical matrices. The investigations can be divided in the characterization of: (i) porosity parameters (ii) hydraulic conductivity parameters (iii) diffusion parameters and (iv) retardation parameters. Imaging of rock porosity was applied to a sequence of altered rocks from Bishop Creek (USA). Different imaging techniques were applied and compared for this sequence: porosity quantification was investigated by digital auto-radiograph, classical PMMA autoradiography, and XRCT microtomography. Classical petrographic observation, and XRD analysis of mineralogy are actually conducted