Application of Fuzzy Concepts to the Visual Assessment of Deteriorating Reinforced Concrete Structures

摘要

Data obtained using visual inspection are qualitative and subjective in nature. Reported methodology utilizes fuzzy sets foi modeling qualitative data. Characteristic distress manifestations corresponding to various deterioration mechanisms in RC structure; and associated repair priorities (conditions) are first classified. To deal with the subjective nature of associated data, independent response: on applicable repair priorities for different distress manifestations are obtained from experts through questionnaire survey. Data obtained frorr questionnaire responses are subsequently used for the development of corresponding fuzzy membership functions (MFs). Visual-inspectior data for various characteristic distress manifestations (on the basis of deterioration mechanism) are recorded individually for every deterio rating element of the structure as per the prepared guidelines. Recorded data are used for the selection of corresponding MFs. Selected MFf are combined according to the proposed fuzzy rule using vertex method to obtain the element MFs individually for all specific deterioration; and for collective effect of all the deteriorations. Defuzzification using area-centroid method provides condition indices. These indices pro vide quantified measure of condition and repair needs of the elements. Element indices are further aggregated to obtain the indices for the structure as a whole. To explain the developed methodology, a brief case study on the assessment of a section of an industrial building i; illustrated.