Review of Expansive Alkali-Aggregate Reactions in Concrete
| Autor: | J. E. Gillott |
|---|---|
| Rok vydání: | 1995 |
| Předmět: |
Aggregate (composite)
Materials science Young's modulus Building and Construction Durability law.invention Portland cement symbols.namesake Cracking Prestressed concrete Mechanics of Materials law symbols General Materials Science Geotechnical engineering Composite material Joint (geology) Alkali–aggregate reaction Civil and Structural Engineering |
| Zdroj: | Journal of Materials in Civil Engineering. 7:278-282 |
| ISSN: | 1943-5533 0899-1561 |
| DOI: | 10.1061/(asce)0899-1561(1995)7:4(278) |
| Popis: | Expansive alkali-aggregate reactions (AAR) are a frequent and worldwide cause of poor durability in Portland cement concrete. In plain concrete, deleterious AAR generally results in expansion and map-cracking, but in reinforced or prestressed concrete cracks may show a linear relationship to reinforcement. Expansion may lead to buckling, extrusion of joint filler, and displacement of equipment set in concrete. White deposits of silica gel, rims surrounding aggregate particles, pop outs, loss of strength, and decrease in modulus of elasticity may occur. Damage may be so severe that concrete has to be replaced, but less drastic remedial measures have been tried when the damage is less severe. Aggregates likely to cause expansive AAR may be identified by petrographic methods, length-change tests, and examination of deteriorated concrete made with similar materials and exposed to similar conditions. Potential expansion due to AAR may be minimized by reduction of the available supply of alkalies in concrete, use of mineral and chemical admixtures, design to limit wetting and the beneficiation of aggregates. Classification of the types of reaction and mechanisms of expansion are reviewed. |
| Databáze: | OpenAIRE |
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