On the effect of ASR cracking on the mechanical behaviour of concrete in tension and compression

BATIC, O; GIACCIO, G.; ZERBINO, R.

Beijing, China

Congreso; 12nd ICAAR; 2004

ICAAR

Many examples of degradation of concrete structures produced by alkali silica reaction (ASR) have been reported. The internal crack pattern generated by ASR affects both transport and mechanical properties. This paper compares the mechanical response of a reference concrete (without reactive aggregates) and a reactive concrete prepared with the same mixture proportions and component materials. Natural siliceous sand (non reactive) and a high alkali OPC were used (total alkali in concrete: 5.25 kg/m3 Na2Oe). In reference concrete coarse aggregate was a granitic crushed stone. Reactive concrete incorporated 10 % of a highly reactive siliceous orthoquarzite as a part of the coarse aggregate. Coarse aggregate particle gradation range between 5 and 19 mm. Concretes were moist cured at 38 °C. Linear expansions were periodically measured, achieving values of 0.099 and 0.143 % in concrete prepared with reactive aggregates at the ages of 60 and 120 days. Microscopic observations were performed on thin slides in order to analyse concrete microstructure. The effects of the presence of ASR cracking on the behaviour of concrete in tension and compression are discussed. The results of compressive strength, elastic modulus, Poisson´s ratio and the load-displacement curves are included.