Title: Performance Of Recycled Aggregate Concrete Aggregate Quality And Durability Requirements

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Publication: CIA

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Date: 2/13/2011

Abstract:
Combined laboratory and field trials have been conducted to assess the effects of aggregate properties on the performance and durability of recycled aggregate concrete (RC). Inclusive in this investigation are the impacts of chloride conductivity, carbonation and water sorptivity of a 25 MPa recycled aggregate concrete. Several other critical parameters for satisfactory performance of recycled aggregate have been assessed. It is observed that the water absorption values of recycled aggregate concrete samples were typically over 25% higher than equivalent strength reference concretes. Corresponding carbonation rates of RC and reference concrete specimens were however comparable, but the abrasion loss of RC samples increased by about 12% compared to the reference mix. A parabolic rate law for carbonation was observed for RC as with reference mixtures, suggesting a direct correlation between concrete quality and transport of fluids. The permeability measurements correlate well with the characteristic strengths of fully cured RC specimens exposed under service conditions, enabling inferences to be made between recycled aggregate properties, concrete mix design parameters and deterioration processes.