Volume 3, Issue 3 (March 2006)
Mechanical Properties of ASR-Affected Concrete Containing Fine or Coarse Reactive Aggregates
This experimental study was conducted to investigate the effects of the alkali-silica reactivity (ASR) on the mechanical properties of concrete, and in particular the strength and the modulus of elasticity under direct tension. Two highly reactive aggregates, a coarse (Québec City limestone) and a fine (Texas sand) were used. The results suggest that the effects of ASR on the mechanical properties of concrete may vary with the reactive aggregate involved. At least, they depend on the particle size and/or the degree of reactivity of this aggregate. The direct tensile strength was the mechanical property of concrete, the most affected and the most-rapidly affected by ASR. At 0.1 % expansion, for instance, concrete cylinders cast with the Québec City limestone showed moderate losses of 16 % in compressive strength and in splitting strength (Brazilian test), but as high as 48 % in direct tensile strength. The modulus of elasticity presented similar values in compression and in direct tension, and its reduction also gives a very good idea of the progress of the damage due to ASR. At 0.1 % expansion, for instance, concrete cylinders containing the Québec City limestone showed a loss in modulus of 19 % in direct tension and 23 % in compression.