Experimental determination of intrinsic permeability of limestone and concrete: Comparison between in situ and laboratory results

The study is concerned with development of the method of in situ measurement of air permeability of porous media. The method applied consists of creating a vacuum in a drilled hole and then studying the increase in pressure over time. The dimensions of the hole are small enough to consider the test as being nondestructive. The paper is composed of three parts. The first one develops the theoretical background used for interpretation of experimental results. The second part describes experimental procedure and device for in situ measurements. The parametric studies of principal factors which may influence the measurements such as the sampling frequency, the observation time and the boundary conditions were performed. The last part includes a discussion of results of the measurements of air permeability performed on large blocks of limestone and concrete. These blocks simulate in situ conditions. On the other hand, from these blocks, cylindrical samples were cored and standard gas and liquid laboratory tests were carried out. The results obtained show good agreement between intrinsic permeability obtained with the in situ device and laboratory tests, confirming the usefulness of the proposed tool.