Quantification of environmental aggressiveness towards reinforced concrete structural elements
- Proposed environmental aggressiveness factor (EAF)
- Quantifies the environmental aggressiveness
- Uses the concept of additive fuzzy system
- Takes into account:
- ambiguities in selection of exposure condition
- effect of temperature
Proposed method for determination of environmental aggressiveness factor for characterizing the aggressiveness of the environment
Markov chain modelling of crackwidths in RC flexural members subjected to fatigue loading
- Nonhomogeneous Markov chain model for evolution of maximum crackwidth with applied load cycles
- Useful for computing reliability of system, against the limit state of maximum crackwidth under fatigue loading
- Proposed equation for characteristic maximum crackwidth (w*)
Unconditional probabilities of different states of beam at different load cycles (x – experimentally observed state)
Virtual aging concept for maintenance scheduling of corrosion affected RC structural elements
- Integrates the concepts of:
- virtual aging
- failure rate
- time-variant reliability
- Helps in selecting the optimal time and degree of repair at the design stage
Time variant reliability analysis as a tool for maintenance scheduling
Durability-based service life estimation of reinforced concrete structural elements
- Methodology for durability-based service life estimation of reinforced concrete flexural elements
- Degradation mechanism – chloride-induced corrosion of reinforcement
- takes into consideration the fuzzy and random uncertainties
Proposed methodology for service life design
Recommendations to BIS
Based on the studies carried out at CSIR-SERC, recommendations, which improve upon the existing durability- and serviceability-related provisions for the design of reinforced concrete structural elements in IS 456, are proposed. These recommendations will be useful while standardising of the Indian codes to meet international safety requirements.
- Durability-based service life design
- Service lives for different types of structures
- Quantification of environmental aggressiveness
- Detailed exposure classification
- Critical chloride content value
- Minimum cover for reinforced concrete slabs
- Reliability-based design of concrete cover thickness
- Reliability analysis for the selection of type of surface coating
- Serviceability limit state