Importance of W/C ratio on compressive strength of concrete in hot climate conditions

Under standard conditions, an increase in W/C ratio would generally lead to a fall in the concrete strength. However, in hot weather, water addition would not give the same result. This quantity of additional water can offer sufficient moisture to the hydration process to evolve under more or less valid conditions. It would also consist in maintaining workability and compensating at the same time the mixing water lost by evaporation. This can be considered at the mix design of the concrete. The addition of water can be estimated starting from the ACI abacuses, which can rather precisely calculate the flow of evaporation of the surface moisture of a freshly placed concrete according to the local climatic conditions. This study, indeed, showed that under severe conditions in a hot climate, the introduction of this supplementing quantity of water, in other words, the increase in the W/C ratio, until a certain limit, has no marked influence on the strength of concrete.