Cylindrical Chamber: A New In Situ Method for Measuring Permeability of Concrete with and without Admixtures

Because the permeation of water through concrete causes both physical and chemical deterioration, the durability of concrete structures is mainly dependent on the concrete permeability. According to the literature surveyed by the authors, the only reliable test that measures the water permeability of concrete is the laboratory standard test of BS EN 12390-8, Testing Hardened Concrete. Depth of Penetration of Water under Pressure. Therefore, having realized the need for an in situ method for measuring the water permeability of concrete, this article introduces the newly developed method of "cylindrical chamber," which is proposed and developed by M Naderi. In order to be able to prove the acceptability of this new method, a total of 102 concrete cubes with dimensions of 150 mm and different compressive strengths and mixtures were prepared, and their water permeability were measured using both the laboratory standard test of BS EN 12390-8 and the cylindrical chamber method. The concrete mixtures employed contained 5, 10, 15, and 20 % of silica fume, plus fly ash, zeolite, and limestone powder. The results obtained tend to show a very good agreement between the corresponding water penetration depths associated with the two methods. In this regard, a linear relationship is seen to exist between the two comparative sets of results with a determination coefficient of 0.9489. It is also seen that the addition of the previously mentioned admixtures decreases the water permeability of the concrete when compared with the permeability of concrete containing portland cement alone. The optimum replacement level of zeolite and limestone powder was also found to be around 10 %. Meanwhile, no optimum content was seen for silica fume and fly ash.