00637653

Monograph

http://onlinepubs.trb.org...nepubs/shrp/SHRP-C-342.pdf

Part I of this report is a synthesis of knowledge of mechanisms of damage to concrete by alkali-silica reactivity. The details of the alkali silica reaction are discussed, and it is noted that the process is complicated by the effects of drying and growth of shrinkage cracks in exposed surfaces. The presence of chloride salts accelerates alkali-silica reactions. Formation of Friedel's salt and other complex chloride containing salts complicates test results. Part II of the report identifies 10 specific gaps in knowledege of alkali-silica reactions in concrete that limit the ability to control these reactions or to predict performance of concrete with reactive aggregates. These involve rapid and reliable test methods; moisture conditions in highway structures; effects of salts, role of sulfate reactions accompanying expansions caused by reactivity; measurement of aggregate reactivities; effect of restraint on kinetics; mechanisms by which pozzolans prevent expansion; test methods and specifications for pozzolans; and inhibition of reactivity by chemical agents.

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SHRP-C-342

English

105 p.

1993-5

0309056020

Figures; References; Tables

Aggregates; Alkali silica reactions; Concrete; Pozzolan; Research; Specifications; Sulfates; Test procedures

Strategic Highway Research Program

Geotechnology; Highways; Materials; Research; I32: Concrete

TRIS, TRB, ATRI

Oct 25 1993 12:00AM