As construction in urban centers increases internationally, many concrete infrastructures are being built at 100 m or more underground, and the influence of groundwater on these facilities is also increasing. Accordingly, the importance of waterproofing and leak-proofing technology for securing long-term durability and safety of underground concrete facilities has been greatly emphasized. The most important required performance of such leak repair technology is to withstand structural behavior and groundwater pressure well. Currently, as a leak repair material for underground concrete facilities, a synthetic rubber-based polymer rubber gel with adhesive flexibility is used internationally. However, quantitative data on how deep the material can perform underground are lacking. In general, the water pressure resistance evaluation of leak repair materials only checks whether it withstands the water pressure of 30 m (0.3 MPa) underground. Therefore, in this study, the toughness of the synthetic rubber polymerized gel (SPRG) leak repair material was calculated using three factors: viscosity, cohesive strength (adhesion strength), and elongation, and an analysis method that can be replaced with water pressure resistance was proposed. In addition, in the correlation between toughness and underground water pressure, it was possible to find out the thickness of the leak repair material used by the underground depth. As a result, it was possible to know the required thickness of the leak repair material according to the depth of the structure to be built underground.

In the field of waterproofing concrete structures, the use of self-adhesive waterproofing sheets has become a popular technique for ensuring long-term waterproofing performance. One important characteristic of such sheet materials is maintaining their stable adhesion strength over an extended period. Adhesion testing serves as a crucial method for assessing the long-term adhesion performance. However, a standardized test method, including equipment and criteria, for directly measuring the adhesion strength of waterproofing sheets applied to onsite concrete walls has not yet been established. Therefore, reliance on laboratory evaluation results has been the only option thus far. In this study, a field-applicable adhesion measurement device was developed in an effort to provide a quality control method for self-adhesive waterproofing sheets and to demonstrate the validity of a standardized evaluation method utilizing this device. The developed adhesion measurement device was designed based on the principle of the peel-out test in compliance with the requirements outlined KS F 4934, where the test specimen backing plate can slide into a 1:1 ratio at the same distance as the rise of the tension jig when the tension jig is raised at a 45° angle. By utilizing this device, the adhesion strength values of self-adhesive waterproofing materials applied in the field were compared with those obtained using a laboratory universal testing machine (Salem, MA, USA) (UTM) on the test specimens. Comparative analysis yielded that the standard deviation of the results varied for the tested waterproofing materials, and the overall standard deviation for the UTM measurements was 0.17, while it was 0.18 for the portable field measurement equipment. The results of the comparison indicated that when limited to the scope of the KS measurement method specifications, the possibility for a wider scope of usage can be made possible with more data and studies.