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Characterisation of shape of fine recycled crushed coloured glass and the effect on the properties of structural concrete when used as a fine aggregate replacement

In order to reduce the use of landfilling within waste management great emphasis is being placed on waste reduction and recycling. Each year in the UK approximately 2.5 Mt of waste glass is produced and approximately half of this waste is not recyclable. Therefore alternative ways need to be found for using waste glass and one possibility is to use it within concrete as a replacement for cement and/ or aggregate. In the research programme concrete mixes were tested which had 0%, 25%, 50% and 100% of the fine aggregate replaced by crushed waste glass. All glass was originally in bottle form and was crushed to produce ‘sand’ which had a grading curve more-orless identical to fine aggregate obtained from a commercial supplier. Three colours of glass were studied, i.e. flint (clear), amber and green. Concretes were also made which contained a mixture of colours (in proportion according to the weight of each type of waste glass produced annually within the UK) and also a mixture of unwashed waste glasses. The overall concrete mix adopted for investigation, i.e. 1:2:4, was selected because of its wide use within industry, and all concrete was made with a water:cement content of 0.6 without the addition of plasticiser or ASR-retarding agents. The suite of laboratory tests included; slump, flow, initial and final setting time, ultrasonic pulse velocity, water absorption by immersion and capillarity rise, ASR measurement (volumetric and linear), compression strength at ages from 7 days to 365 days. Techniques of developed digital imaging and processing have been applied to the glass aggregate to quantify various particle shape factors, i.e. aspect ratio, percentage concavity, Riley inscribed sphericity and surface texture index. Statistical analysis has been used to compare the distribution of particle forms present within the fine aggregate materials used in the experimental work. Dimensional changes (in three orthogonal directions) were measured as concrete cubes hardened over a period up to 365 days. The length changes of concrete prisms were also measured over the same period of time. The resultant data indicated that a fine aggregate which comprised 25% glass and 75% sand would be categorised as “non-expansive”, i.e. the same as the sand on its own. As the proportion of glass in the fine aggregate became greater than the aggregate became more expansive but it did not exceed recommended limits.

Identiferoai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:659044
Date January 2014
CreatorsKoh, Chon Jin
PublisherUniversity of Wolverhampton
Source SetsEthos UK
Detected LanguageEnglish
TypeElectronic Thesis or Dissertation
Sourcehttp://hdl.handle.net/2436/561256

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