Showing papers by "Marc-André Bérubé published in 1987"

Le barrage Sartigan dans la Beauce (Québec), Canada : un cas-type de détérioration du béton par des réactions alcalis–granulats

Abstract: The Sartigan dam, a concrete ice-retention dam built in 1967 along the Chaudiere River, near Saint-Georges de Beauce, Quebec, Canada, shows numerous megascopic and microscopic signs of alkali–aggregate reactivity of the alkali–silica type (expansion, polygonal map cracking, silico-alkaline gels, looseness of cement paste – aggregate bonds, characteristic rims on fracture surfaces through coarse reactive aggregate particles, etc.). Besides, the three conditions considered as essential to promote these reactions in concrete have been satisfied in this case: the use of a high-alkali cement, conditions of high humidity reinforced by frequent wetting–drying cycles, and aggregates considered as potentially alkali-reactive in concrete (rhyolitic tuffs with a devitrified matrix rich in microcrystalline quartz).

Condition survey of concrete structures built with potentially alkali-reactive limestone aggregates from the quebec city area (quebec, canada). concrete durability. katherine and bryant mather international conference, held at atlanta, georgia, usa, 27 april-may 1987

Abstract: This paper reports the results from the condition survey of about 300 concrete structures of the Quebec city area, with a significant proportion of them showing signs of deterioration commonly associated with alkali-aggregate reactions. Each component of these structures has been described according to the more common defects affecting concrete structures and to exposure conditions. Core samples have been taken in about 70 structures and investigated for physico-mechanical properties, air and chloride contents. Each sample has also suffered a petrographic examination. This study has been done to determine the present condition of these structures, to recognize the occurrence and the severity of the major defects affecting them and mainly to establish the influence of the alkali-aggregate reactivity on deteriorations. (Author/TRRL)