2018 Volume 29 Pages 33-40
This paper presents the results of the investigation of a new method for evaluating the quality of the upper surface of concrete slabs with a surface water absorption test (SWAT) developed by the authors. Methods to measure the moisture content of concrete at the depth of 5mm from the surface were investigated considering parameters such as W/C, type of cement and curing conditions. It was found that the moisture content of concrete at the depth of 5 mm from the casting surface can be detected by the HI-100 moisture tester (manufactured by Kett) and the concrete can be judged to be sufficiently dry when the count value of the device is below 120. When the count value was below 120, the quality of the concrete at the upper surface of the slab could be evaluated by using the cumulative water absorption amount over a duration of 100 seconds. In conclusion, the count value of 120 can be used as an index for detecting the decrease in scaling resistance of concrete due to micro-cracking at the surface.
