the cumulative flow
of water into the concrete at a pressure of 500 mbar was recorded
every minute for a duration of 15 min.
Fig. 10 shows the volume of water plotted against the square
root of time according to the recommendations of The Concrete
Society (2008). A regression equation for each specimen was
determined, and the gradients of the lines between the 5th and
15th reading, which is known as the water permeability index, are