A study on low energy demand materials used in glasscrete to counteract alkali-silica reactions

The potential of waste glass use in concrete as an alternative outlet to landfilling is excellent; however glasscrete (i.e. concrete with glass aggregate) suffers from durability problems caused by alkali-silica reactions (ASR). The use of pozzolanic materials to counteract ASR has been increasingly studied. This paper investigates the ability of selected low-energy demand binders/pozzolans to counteract ASR in glasscrete: these include paper sludge ash (PSA), a by-product of the paper making industry, used together with a standardised pozzolanic material for concrete, i.e. Pulverised Fly Ash (PFA) an industrial byproduct of electric power stations. A number of laboratory tests were performed on the different glasscrete mixes to assess properties (workability, compressive and tensile strengths and elasticity moduli and water absorption). Mortars were also tested for alkali-silica reaction (ASR) using the accelerated mortar bar test, which showed that ASR was effectively counteracted, towards better glasscrete durability. Glasscrete mixes were identified, with similar strengths as the respective control mixes with natural aggregates. Workability was however affected in all mixes and should be addressed in further research.