Seiya NITTA

Application of clinical methodology on diagnosis of concrete structures

Takumi SIMOMURA

In Japan, there are numerous researches on deterioration and deformation of concrete structures, various researches have been done on the various factors that greatly affects the deformation and deterioration of concrete structures. It is important to ascertain the cause of deterioration from the deformation generated in the structure, to judge the degree of progress of deterioration and to take appropriate measures.
The diagnostic procedure in medical treatment and that of concrete structures are similar, therefore, it is possible to produce a diagnostic method with reference to clinical methodology. This paper intends to produce a diagnostic maintenance and management system for concrete structures with reference to medical care diagnostic methodologies.The diagnostic methodology is inferred from the diagnostic measures applied in determining the cause of diseases in patient's based on the patientfs symptoms, which guides in the examinations and step of medical treatment for such patient disease.
In this research, in order to apply a diagnostic methodology to the diagnosis of concrete structures and to produce a diagnostic system capable of judging the deterioration phenomenon and soundness, it was important that the various conditions affecting the strength and soundness of concrete structures be duly documented, by creating a diagnostic system with a flow chart.  it is easy to judge whether the flow chart works by setting up a filter that organize the mechanisms of deterioration phenomenon that occurs in the structure and create a diagnostic system that can roughly estimate the deterioration progress in concrete. For judgment of soundness, crack width was used as quality factor, based on the appearance of concrete following standard specifications. The developed systems were tested and its results were compared with diagnosis of from engineerfs datafs in the field. It is assumed that the estimation of deterioration and soundness of concrete structures affected by one factor was possible by inputting crack width value in the flow chart developed. And given that results of the diagnosis system obtained the same diagnosis results from previous works, the practicability of the system was confirmed. Also, eight masterfs students from the concrete laboratory of Nagaoka University also evaluated the system obtained a similar judgment on the same structure diagnosis, hence the efficacy of the flowchart was confirmed.In addition, when multiple factors act simultaneously, the estimation of deterioration mechanism becomes complex, so there is a need of re-evaluating the flow chart to compensate for such simultaneous actions. This study should be conducted as further assignment in the nearest future.