Aspects of the assesstent of concrete quality

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This thesis deals with the development of a new technique using a scanning electron microscope and computer for quantitative analysis. the aim is to determine the degree of hydration and porosity of ordinary portland cement paste with some application to mortars and concretes. firstly the technique has been applied to cement paste to establish a correlation between the degree of hydration determined by scanning electron microscope and that determined by quantitative x-ray diffraction analysis. sample preparation has àa major influence on the analysis by these techniques, problems associated with quantitative analysis were reported. secondly, it was applied to concrete and to two site case studies of mortar and concrete. in addition porosity by methanol exchange and strength were investigated. the technique has given satisfactory correlation for the degree of hydration determined by the two methods. it is therefore assumed to give reliable results for mortars and concretes considered in the two case studies. assessment of the degree of hydration by the sem can be used to solve problems in practice, work is continuing on the effects of curing on large samples and further work is recommended.