Objectif DURABILITY OF CONCRETE MATERIALS, EITHER AS MATRIX FOR LOW AND INTERMEDIATE LEVEL WASTE, OR AS BACKFILLING/SEALING MATERIALS FOR REPOSITORIES, IS A MAJOR CONCERN IN THE PREPARATION OF BOTH DESIGNS AND SAFETY ASSESSMENTS. THE OBJECTIVE OF THIS STUDY IS TO EXAMINE ANCIENT CONCRETES, AND MODERN ONES WITH PROVEN DURABILITY; TO IDENTIFY THE PARAMETERS WHICH CONTRIBUTE TO THEIR DURABILITY. THE WORK IS AN EXTENTION TO THAT PREVIOUSLY UNDERTAKEN ("AN HISTORICAL EXAMINATION OF CONCRETE" (EUR 10937) REPORTED MARCH 1986) IN WHICH A NUMBER OF FACTORS WHICH APPEARED TO BE SIGNIFICANT IN RELATION TO DURABILITY WERE IDENTIFIED. THE RESULTS WILL BE USED TO PROVIDE DATA TO ENABLE LIFE PREDICTIONS ON MODERN CONCRETES TO BE MADE. THE FOLLOWING SOURCES OF SAMPLES WILL BE INVESTIGATED: 1.1 ANCIENT MATERIALS PREFERENCE WILL BE GIVEN TO OBTAINING SAMPLES FROM CONCRETES CONTAINING NATURAL POZZOLANIC MATERIALS, WHERE THE SAMPLE IS PARTIALLY BURIED AND FROM ZONES OF THE CONCRETE WHERE CARBONATION MAY BE INCOMPLETE. 1.2 MEDIEVAL MATERIALS (UP TO 1824) PREFERENCE WILL BE GIVEN TO MATERIALS WHERE A HYDRAULIC BINDER IS LIKELY TO HAVE BEEN USED. 1.3 MODERN PORTLAND CEMENT BASED CONCRETES (1824 - PRESENT) PREFERENCE WILL BE GIVEN TO SECURING SAMPLES FROM LARGE MASSES OF UNDERGROUND CONCRETE LOCATED IN A MOIST ENVIRONMENT AND WITH A LIKELY POZZOLANIC CONTENT. 2. EXAMINATION & TESTING THE PROCEDURE SET OUT BELOW WILL BE FOLLOWED WHERE APPROPRIATE, DEPENDING ON THE SIZE AND NATURE OF THE SAMPLE AND THE OUTCOME OF PREVIOUS TESTS: 2.1 VISUAL EXAMINATION 2.2 ASSESSMENT OF DEPTH OF CARBONATION 2.3 OPTICAL MICROSCOPY OF THIN SECTIONS TAKEN AT POSITIONS REPRESENTING FULLY CARBONATED MATERIAL, THE CARBONATION FRONT AND UNCARBONATED MATERIAL. 2.4 SCANNING ELECTRON MICROSCOPY OF POLISHED SECTIONS AND FRACTURE SURFACES IN THE SAME ZONES. 2.5 INDIVIDUAL PHASES IDENTIFIED ABOVE ANALYSED BY ELECTRON PROBE MICROANALYSIS. 2.6 CHEMICAL AND XRD ANALYSIS OF PORTIONS REPRESENTATIVE OF THE DIFFERENT ZONES OF THE SAMPLE. 2.7 PORE STRUCTURE ANALYSIS OF SIMILAR PORTIONS. 2.8 ANALYSIS OF PORE FLUID EXPRESSED FROM THE PORTIONS USED IN 2.7. 2.9 OTHER TESTS MAY ALSO BE MADE TO RESOLVE ISSUES ARISING FROM THE RESULTS OF THE ABOVE PROCEDURE. Champ scientifique natural sciencesphysical sciencesopticsmicroscopyelectron microscopy Programme(s) FP1-RADWASTOM 3C - Research and development programme (Euratom) on the management and storage of radioactive waste, 1985-1989 Thème(s) Data not available Appel à propositions Data not available Régime de financement CSC - Cost-sharing contracts Coordinateur Taylor Woodrow Construction Ltd Contribution de l’UE Aucune donnée Adresse Taywood House 345 Ruislip Road UB1 2QX Southall Royaume-Uni Voir sur la carte Liens Site web Opens in new window Coût total Aucune donnée