A series of small size RC beams were introduced with different crack widths and then treated with silane-based water repellent on the surface and inside the concrete.Their water absorption properties were then evaluated.The results indicate that a linear function of square root of time could describe well the water absorption for cracked concrete within 4 h of the test,the coefficient of water absorption increases with the increase of crack width following an S shape.For the cracked concrete with surface wa...