Figure 5: Variation of porosity with Depth of concrete slabs cured using different methods

It is apparent that the ranking order of the different curing methods is the same as that observed with the previous two tests. However, it can also be seen that the differences decrease with increasing depth and that at depths greater than about 50 mm the differences become insignificant. This infers that the concrete more than 50 mm from an exposed surface will be little affected by the curing conditions at the surface. The results in Fig. 5 show that at 10 mm depth the concrete which had not been cured had a porosity approximately 30% more than that cured by ponding for 3 days.