Artificial-Crack-Behavior Test Evaluation of the Water-Leakage Repair Materials Used for the Repair of Water-Leakage Cracks in Concrete Structures
There are no existing standard test methods at home and abroad that can verify the performance of water leakage repair materials, and it is thus very difficult to perform quality control checks in the field of water leakage repair. This study determined that the key factors that have the greatest impact on the water leakage repair materials are the micro-behaviors of cracks, and proposed an artificial-crack-behavior test method for the performance verification of the repair materials. The performance of the 15 kinds of repair materials that are currently being used in the field of water leakage repair was evaluated by applying the proposed test method. The main aim of such a test method is to determine if there is water leakage by injecting water leakage repair materials into a crack behavior test specimen with an artificial 5-mm crack width, applying a 2.5 mm vertical behavior load at 100 cycles, and applying 0.3 N/mm2 constant water pressure. The test results showed that of the 15 kinds of repair materials, only two effectively sealed the crack and thus stopped the water leakage. The findings of this study confirmed the effectiveness of the proposed artificial-crack-behavior test method and suggest that it can be used as a performance verification method for checking the responsiveness of the repair materials being used in the field of water leakage repair to the repetitive water leakage behaviors that occur in concrete structures. The study findings further suggest that the use of the proposed test method makes it possible to quantify the water leakage repair quality control in the field.
A Study on the Construction Methods of Sealer of Injection Type for Leakage Maintenance for Water Leakage and Cracks in Concrete
Since water leakage and cracks are not the source of serious problems such as long-term lowering of performance and durability of a stricture, including damages to operating facilities of a structure, damages to internal finishing materials, exhibition, and goods, and pollution of residential environment, they might have led to development of positive coping skills; however, an instant loss of lives or property due to earthquake, explosion, typhoon, or a fire was indeed neglected. In these days, repair materials for leakage cannot help but being taken in temporary way without any noticeable countermeasure. This kind of repair is socially criticized many times that is defective construction even if this costs a lot. It was not arrange the standard for construction methods of sealer of injection type for leakage maintenance, even it has been used various type of construction methods for leakage part. In conclusion, we suggest that the construction methods of sealer of injection type for leakage maintenance for leakage to establish the leakage repairing technology as increase of structure demand. Therefore, it would be possible to provide a stage-by-stage solution by developing systematic research activities among the industry, schools, and research institutes to spread maintenance management techniques globally through technical solution to water leakage and cracks, acquisition of structural safety with prolonged durability for life cycle, reduction of water leakage repair expense s, and so on.
IMPROVED DESIGN OF TUNNEL SUPPORTS. VOLUME I: SIMPLIFIED ANALYSIS FOR GROUND-STRUCTURE INTERACTION IN TUNNELING
The purpose of this report is to provide the tunneling profession with improved practical tools in the technical or design area, which provide more accurate representations of the ground-structure interaction in tunneling. The design methods range from simple analytical and empirical methods to sophisticated finite element techniques as well as an evaluation of tunneling practices in Austria and Germany. Volume 1 describes a simplified analysis method for ground structure interaction in tunneling, which is necessary because of the indeterminate relationships which describe the realm of tunneling parameters. The method is geared toward hand calculations that incorporate the effects of three of the most significant factors influencing the ground structure behavior. The authors point out that it is doubtful that the complex interrelationships among the nearly countless variables in any real tunneling problem can ever be rigorously analyzed, even using the most sophisticated numerical techniques. As an alternative approach, the simplified method focuses on the essential elements of very complicated phenomena in order to isolate the three major factors that have an overriding influence on support loads. These factors are: (1) the relative stiffness of the support and ground mass; (2) the spatial lag or delay of support construction behind tunnel face; and (3) the yielding of ground mass as its shear strength is exceeded. Using these factors, the intent of Volume 1 is to provide an analysis in which accentuated computational ease, coupled with sufficient accuracy, makes the simplified method a valuable and effective design tool for use in preliminary design, for parametric studies in final design, and for updating the design during construction.