MEASURING METHOD FOR VOID RATIO OF POROUS CONCRETE APPLYING PRESSURE METHOD

Accurate measurement of void ratio is essential for porous concrete, since its attractive performances are mainly determined by the continuous void. Measurement methods of air void ratio of porous concrete are prepared in the technical committee report of Japan Concrete Institute i.e. volumetric method and weighing method. In order to measure the void ratio of various types of porous concrete with wide range of aggregate size, however, it is sometimes difficult to apply them when a high accuracy is required. Especially, when small size aggregates are used for porous concrete, the error of measurement is not negligible because the amount of retained water in the pore during a measurement procedure is not expected to be very small. In the present study, in order to solve this problem, the authors have proposed a new method using an air meter, which realizes a clear separation of the sort of voids i.e. continuous, semicontinuous, and independent voids. Also, rather high accuracy can be expected and the required time for the measurement can be reasonably shortened.