Study On The Durability Design Of Concrete Structures

Durability problems of reinforced concrete structures are being more and more urgent now. Too much money have to be spent to repair damaged structures. In China, massive civil works are proceeding now. To avoid durability problems, the same as that in deveoped contries, more studies shall be conducted to present a resonable durability design system.Based on existing researches, the author conducted full researches on the durability design system for reinforced concrete structure. The main works are as below:1. The damage concept for concrete structures under both environmental and load effections is defined, and a durability design system is established. This new system aims at the control of ultimate damage state of concrete, including environmental effection, life design, status control, material design, repairable design, constitution design and monitoring design. Besides, profound studies on life design, status control and repairable design are carried out.2. Damage is the main performance index for concrete durability. Based on this concept and analysis of service ability limit state, durability limit state and test results, the limit state can be determined according to different damage state.3. Based on the three limit states in damage form, the reasonability of using law equation for life design of concrete structures is discussed.4. The anti-measures towards damage extention is studied and design method is followed aiming at different damage limit state. Design method and analysis equation for damage inhibition are presented corresponding with FRP and stirrup methods.5. Based on whole-life and phased design idea for concrete strucutre, repairable design method for concrete structure durability is presented. Additional safety factor is attached to the calculation formula. Factor values for different members are suggested also. Besides, the fomula for repairable design of structures is brought out.6. A series of tests were conduted aiming at the anti-damage measures of FRP and stirrups. The damage inhibition effection and influence on member performance are analyzed.7. Test of compressed columns were conducted to certify the repairable design method...