Measuring the Permeability and Compressive Strength of Concretes Containing Additives in Freeze–Thaw Conditions without Breaking the Sample

Abstract

One of the most important factors influencing concrete durability is permeability. Permeability testing is conducted according to certain standards to measure the water permeation in concrete. After the test, the concrete specimens should be positioned under the concrete breaker jack and split into two sections to measure the permeability. In general, it is difficult to use the majority of permeability tests to determine concrete permeability in situ. As a result, the permeability and compressive strength of concrete with various strength classes were measured in this study by using the novel “cylindrical chamber” and “friction transfer” tests. Permeability-reducing admixtures, including Fibrous microsilica gel and waterproof, were used in several specimens that were subjected to 0, 50, 100, and 150 freezing and thawing cycles. A cylindrical chamber device can quantitatively display the permeation volume and rate of any liquid into concrete. By comparing the results of the nondestructive cylindrical chamber test with the standard destructive test, it was observed that there is a 97.6% correlation coefficient between the results. This correlation coefficient demonstrates the high accuracy of the cylindrical chamber test in measuring water permeability within concrete without the need for sample breakage. Furthermore, by comparing the results of the friction transfer test with the standard destructive test, a 94.2% correlation coefficient was observed. This correlation coefficient indicates the high accuracy of the friction transfer test in assessing the compressive strength of concrete without the need to break the concrete. In addition, the process of rising permeability rate has a greater value for low cycles. However, it progressively becomes smoother for higher cycles, in such a way that, on average, the permeation volume increased by 71% in the first 50 cycles, 21% in the second 50 cycles, and only 8% during the third 50 cycles. In concrete specimens without additives, the value of permeability rate increases under freezing and thawing cycles by approximately 36% and 19%–22% in specimens containing permeability-reducing admixture.