title: Evolution of porosity in geotechnical composites.
abstract: Nuclear magnetic resonance (NMR) (H1) transverse relaxation measurements were carried out on 37x70-mm cylindrical mineral/organic composites to determine and monitor the porosity evolution. Porosity is related, in principle, to the stability of such materials in geotechnical applications, for example, engineering foundations. The specimens represented novel formulations of mixed "wastes" containing coarse screened mineral, digested sewage sludge, quicklime, and pulverized fuel ash mixed and compacted together to form mechanically competent material. The measurements on a selected formulation indicated initially low porosity (<12%) that becomes lower over 6 months ( approximately 8%) due to pozzolanic reactions occurring. A relaxation time cutoff of 1.5 ms between "bound" and 'mobile' pore water much lower than sandstones (33 ms) was observed. The results confirmed that the NMR method allows a more reliable assessment of porosity and pore-size evolution.
authors.affiliation: Department of Earth Science and Engineering, Imperial College, SW7 2AZ London, UK. pavlos.tyrologou@imperial.ac.uk
authors.forename: Pavlos
authors.initials: P
authors.lastname: Tyrologou
authors.forename: Alvan William L
authors.initials: AW
authors.lastname: Dudeney
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Grattoni
mesh_terms: D001709:Biotechnology / Q000379:methods; D005844:Geology / Q000379:methods; D007220:Industrial Waste / Q000032:analysis*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008420:Manufactured Materials / Q000032:analysis*; D008422:Materials Testing / Q000379:methods*; D016062:Porosity; D012987:Soil / Q000032:analysis*
chemical_list: D007220:Industrial Waste; D012987:Soil