Evaluation of Laboratory Drying Procedures Relevant to Field Conditions for Concrete Sorptivity Measurements

The surface humidities of a limited set of field concretes during summer conditions in Ontario were measured prior to water absorption (sorptivity) testing. A series of alternative laboratory curing conditions was carried out on cores prior to laboratory sorptivity tests, to determine which would best mimic average field conditions (surface humidities greater than 40% and moisture contents greater than 1%). It was found that three days' oven drying at 50°C followed by sealed drying for four days at 50°C as suggested by Parrott worked well. In addition, the moisture content at test was calibrated to measured sorptivity results.