INTRODUCTIONGeneralHot weather may create problems in mixing@ placing@ and curing hydraulic cement concrete. These problems can adversely affect the properties and serviceability of the concrete. Most of these problems relate to the increased rate of cement hydration at higher temperature and increased evaporation rate of moisture from the freshly mixed concrete. The rate of cement hydration is dependent on concrete temperature@ cement composition and fineness@ and admixtures used. This report will identify problems created by hot weather concreting and describe practices that will alleviate these potential adverse effects. These practices include suggested preparations and procedures for use in general types of hot weather construction@ such as pavements@ bridges@ and buildings. Temperature@ volume changes@ and cracking problems associated with mass concrete are treated more thoroughly in ACI 207.1R and ACI 224R.