Author:

Keywords:

Concrete, Recycled, Frost/Thaw, Durability

Abstract:

Literature often concludes that the lower mechanical properties of recycled concrete, compared to standard concrete, is unfavourable for the durability in aggressive environments. One of these aggressive environments is frost. Belgium, with a temperate maritime climate, is a country that experiences many annual frost/thaw-cycles. Before recycled concrete can be used in outside environments, more experimental research is needed. This investigation was set up to determine the resistance of concrete made with coarse recycled concrete aggregates (0-40%), against these frost/thaw-cycles. In this research recycled concrete aggregates originating from mixed demolition containing mainly limestone aggregates and aggregates from road demolition, containing porphyry were used. A second parameter of this research was the influence of different concentrations of air entrainer. In total three reference concrete mixture and twelve different recycled concrete mixtures were made. All fifteen concretes mixtures were exposed to frost-thaw cycles in a 3% NaCl solution. Beside the frost/thaw resistance tests, the hardened density, dynamic modus of elasticity and compressive strength were tested before and after 30 frost-thaw cycles.