Trend, displayed as a function of curing time, of compressive strength (solid lines, left axis) and water absorption (dashed lines, right axis) of three sets of materials: (a) superplasticizer free; (b) with a superplasticizer content of 1%; (c) with superplasticizer content of 2%. Error bars are, for clarity, not displayed due to their overlapping and the possible confusion on reading.