Design and testing of self-compacting concrete
Self-compacting concrete (SCC) can flow into place and compact under its own weight into a uniform void free mass even in areas of congested reinforcement. The research reported in this thesis examined the production of SCC with readily available UK materials, with the overall aims of evaluating test methods and establishing a suitable mix design procedure. There have been significant recent developments and applications of SCC in several countries, notably Japan. A literature survey gave an understanding of the advantages and properties of SCC, test methods and the range of constituent materials and their relative proportions for its successful production. A range of SCC mixes can be produced with the common features of a lower aggregate content than conventional concrete and the use of superplasticizers. Most mixes also contained one or more of pulverized fuel ash, ground granulated blast furnace slag and an inert powder filler. A four stage experimental programme was carried out: *tests on pastes to assess the effect of the types and proportions of the powders and superplasticizers on the rheology. *tests on mortars to determine suitable dosage of superplasticizers for high fluidity, low segregation and low loss of workability with time after mixing. Flow spread and funnel tests were used. *tests on fresh concrete to enable suitable types and quantities of coarse aggregate to be combined with these mortars to produce SCC. Fluidity and viscosity were measured using slump flow and V-funnel tests, and passing ability using L- and U-type tests. Two-point workability tests were also carried out, and a novel way of assessing segregation resistance was developed. *tests on hardened concrete to determine compressive strength, bond to reinforcement and drying shrinkage. A mix design procedure, based on a method suggested by Japanese workers, has been developed. This includes optimisation of the mix with a linear optimisation tool from a commercial spreadsheet package.