Winter concreting in Canada

Abstract

This paper deals with the pros and cons of concreting in sub-zero weather and the practice and theory behind the requirements of the Canadian standards for cold weather concreting. It gives the minimum protection period for initial curing to prevent frost damage and the amount of insulation required to meet the standards for various weather conditions. The problem of the thermal stress produced as the concrete cools under various degrees of restraint is dealt with in detail, and the cooling period required to avoid thermal stress cracks for various thicknesses of structures and weather conditions is given in graphical form. Examples of the use of insulation in slip forming and problems encountered in varying weather conditions are also included. Keywords: winter construction, concrete, insulation, curing, form work (construction), form removal, temperature, thermal shock, water–cement ratio.