Freeze-thaw durability of non-air entrained concrete with normal and lightweight aggregates.

摘要

Concrete failure is generally assumed by the public to be the result of a design error or excessive loading of a specimen. Conversely, durability related issues are the overwhelming cause of concrete failure. These durability issues range in size and exposure to the public. One of the most prevalent durability issues is that of damage caused by repeated freezing and thawing. Conventionally, employing air entrainment prevents this damage. However, with an ever-increasing emphasis on cost saving decision-making, prevention of failure by traditional means may not be acceptable.;In this research the use of porous lightweight aggregates (LWA), high performance concrete (HPC), and employing proper curing time and methods are analyzed in freezing and thawing damage prevention. In exposed conditions today, one or more of these methods are already in place and could avoid the cost of air entraining admixtures.;Shown in this research are HPC mixes that experienced different curing times and methods prior to freezing and thawing. Concrete with varying replacements of normal weight aggregates for LWA also experienced different curing times and methods prior to freezing and thawing. Split tensile and flexural testing occurred to see if there is a correlation of strength to freeze thaw resistance.;Proper combinations of HPC and curing method passed freezing and thawing testing. Also, proper combinations of LWA replacements and curing method passed freezing and thawing testing. On the other hand, most combinations failed the current freezing and thawing test method. No correlation is apparent in this research between split tensile or flexural strength and freezing and thawing resistance.