COLD REGIONS RESEARCH AND ENGINEERING LAB HANOVER NH
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For many years winter concreting has been an expensive as well as a difficult operation and it is becoming even more so with current accelerated building schedules. The primary techniques commonly practiced for placing concrete in the winter include heating the mix materials and providing a suitable protective environment such as extensive, heated canvas or plastic shelters, or adding an insulating material to the form work. An additive of 2 calcium chloride is permitted by most building codes to accelerate the growth of strength and allow faster removal of protection and forms. Most building codes permit the addition of 1 or 2 by weight of cement of calcium chloride. Another method developed in the USSR, is the use of cold concrete. This involves the greater use of calcium chloride and sodium chloride as accelerators, and freezing point depressants. Most of the cold concrete research has been reported in the Russian literature and little has been translated. The purpose of this study was to verify some of the translated data to determine whether this method is practicable and worthy of further investigation. A comparison of USSR compression test results and those of this study showed similarities in the watercement ratios, strengths, and curing temperatures. Salt contents were 1 12 to 2 times those reported in the Russian literature. When cold concrete is more thoroughly investigated it may become competitive winter concreting technique for some purposes.
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