|Budget Amount *help
¥3,400,000 (Direct Cost : ¥3,400,000)
Fiscal Year 1998 : ¥700,000 (Direct Cost : ¥700,000)
Fiscal Year 1997 : ¥2,700,000 (Direct Cost : ¥2,700,000)
In this study, the influence of concrete deterioration and/or reinforcement corrosion on performances of concrete structure, such as bearing capacity, seismic capacity, fatigue property esthetics et al., was mainly examined, and the decline processes of these performances were quantified. The main results of this study are as follows ;
1. Development of computer simulation method for chloride induced reinforcement corrosion :
A computer simulation method for the chloride induced reinforcement corrosion in concrete has been developed in consideration of the effects of micro and macro pores in concrete, on the diffusion processes of chloride and oxygen. This method is useful for evaluating the influence of concrete quality, water content and crack existing in concrete on the corrosion process of reinforcing steel quantitatively.
2. Influence of the reinforcement corrosion on the fatigue property of concrete structure :
An equation predicting the decline of fatigue property of concrete struct
ure due to reinforcement corrosion was proposed. In this equation, the pitting corrosion was introduced as a main factor causing the micro crack propagation into cross section of steel bar. Accuracy of the equation was confirmed by the fatigue test of reinforced concrete beams deteriorated due to the reinforcement corrosion.
3. Influence of defects built up by the inferior construction on the mechanical properties of concrete structures :
When some defects, such as honeycomb, large void and the irregular materials, exist in concrete due to the inferior construction, the mechanical properties of concrete structure would be affected by them. Some experimental study was done for clarifying the influences of the defects on the bearing capacity, toughness and fatigue property of reinforced concrete beams. From the results, it was confirmed that the fatigue property of the beams clearly declined on account of existing the defects in concrete even if no declination sign was appeared on the static bearing capacity.
4. Deterioration prediction of concrete under hot spring water :
Quantitative equations to predict the deterioration of concrete in the hot spring water were provided on the basis of analyzing the data obtained from the exposure tests under the several hot spring areas in Japan. Adequacy of the equations was checked by the results of the exposure test carried out newly in this study. Less