Assessing the Portion of the Crack Length Contributing to Water Sorption in Concrete Using X-ray Absorption

While it is generally known that cracks accelerate fluid movements, there is a need to quantify how cracks influence the controlling transport mechanism(s) for more accurate service life modeling. This paper describes an experimental approach using x-ray absorption measurements to quantify the influence of cracks with varying width and length on water sorption in concrete. Concrete wedge splitting specimens, conditioned to 50% relative humidity, were loaded to varying crack openings. Water sorption was monitored for ponded specimens with varying crack widths and lengths by taking multiple x-ray absorption measurements over time. The effect cracks have on sorption is discussed and compared to the behavior of pristine concrete. In addition, the maximum water sorption depth after one hour of exposure is compared to crack lengths determined by the cracked hinge model.