The Freezing And Thawing Resistance Of Concrete As Affected By Method Of Test

This study, aimed at improving the freeze-thaw resistance of concrete, consists of three parts. Part I evaluates parameters affecting the freeze-thaw durability of concrete. A modification of the existing standard of method for determining the durability factor of concrete specimens is proposed, and a new procedure for fundamental transverse frequency (used in durability factor calculations) has been developed. Part II focuses on developing better methods for identifying nondurable aggregates, and has resulted in a rapid new test based on the hydraulic fracture of aggregates. Part III describes field experiments to evaluate the freeze-thaw resistance of a number of specified concrete mixes and the use of sealants to mitigate D-cracking. Preliminary field performance results are presented.

This investigation studied the effect of interrupted testing combined with prolonged freezing on the freeze-thaw resistance of concretes containing fly ash as part of the cementitious fraction, using ASTM Test Method for Resistance of Concrete to Rapid Freezing and Thawing (C 666-84, Method A). Also studied was the effect of "marginal" air contents on the above test parameters. Test results indicate that for fly ash concretes with air contents in excess of 5%, interrupted and/or prolonged periods of freezing do not affect the freeze-thaw resistance of the concrete. Early age freezing (14 days) of fly ash concretes did not appear to be detrimental to the performance of the fly ash concretes tested.

This book forms the proceedings of the international workshop to be held in Essen, Germany. This workshop summarises the conclusion of the technical committee's investigations into the resistance of concrete to freeze-thaw attack, specific in this to resistance with or without de-icing chemicals. It presents the RILEM recommendations on testing the freeze-thaw and de-icing salt resistance of concrete.

Concrete durability in climates where freezing and thawing occurs is a continuing problem. It is particularly acute for highway and bridge structures, where de-icing salts are used to combat the effects of frost, snow and ice. These salts can cause damage to concrete and accelerate corrosion of reinforcements. This book presents the latest international research on this area, with contributions from North America and Europe which were presented at an international RILEM workshop.