ANOMALOUS EFFECTS OF DRYING AND WETTING ON THE FLEXURAL AND COMPRESSIVE STRENGTHS OF AUTOCLAVED CALCIUM SILICATES

The flexural and compressive strengths of a series of autoclaved OPC s ilica pastes are compared in the oven-dried, as-autoclaved and saturat ed conditions. The silica particle size was varied in the range 3-50 m u m and the water/solids ratio from 0.24 to 0.65. The effects on stren gth and dimensional changes of prolonged exposure to both drying and w etting environments were also studied. A number of anomalous strength changes were observed following both drying and wetting, associated wi th the very fine silicas and the lower water/solids ratios. Possible e xplanations are proposed.