FRC Segments Design Research And Project Application

FRC (Fibre Reinforced Concrete) as a new type of composite building materials has excellent physical and mechanical properties. Compared with ordinary concrete, FRC's tensile strength, flexural strength, abrasion resistance, impact resistance, corrosion resistance, fatigue resistance, toughness and cracking resistance, antiknock properties can be increased. It has been conducted the deep research and the widespread project practice on overseas. However, the current domestic research in this area is less. Because of lack of complete and reliable test data for the design of the segments, its application was limited.Based on the "precast FRC shield segments of a comprehensive study and application "topics, I analysed FRC shield segments strength enhancing and cracking resistance mechanism. Through numerical simulation, analysed the linear relationship between the volume of steel fiber content and Anti-crack effect and gained the minimum volume of steel fiber content.According to the subject early research results, proposed the FRC shield segments mixing design, material parameters and design parameters, has done the system research about FRC shield segments capacity design methods and further improved the design methods of the FRC ramp section capacity on off-center compression. Through FRC early age anti-shrinkage test and resistivity test etc various durability test, reached FRC shield segments durability design basis and gained the steel fiber content control standards.Based on FRC shield segments application test, FRC shield segments internal forces met the design capacity and had sufficient security reserves, also can significantly reduce the cracks in construction process. The results confirmed FRC shield segments anti-cracking etc safety performance is better than conventional concrete segments. Through the practical application, we verified that FRC shield segments mixing, material index, design strength, design parameters and other research results were correct.Through the stress of bolt on the joint, joint opening displacement, the ends of stress measurement, analysed some laws about longitudinal, toroidal joint mechanical effect and influence of stress transfer about staggered joint to linking segments, gained a moment transfer coefficient. Thereby simplified the staggered linking numerical simulation model and ve?ified the moment transfer coefficient reasonable from the measured data.Through jack thrust simulation, analysed pattern and cause of damaged segments. The simulation results coincided with the field tes and showed FRC shield segments can effectively control cracking damaged in the construction phaseSo far, results of this study confirmed FRC shield segments for the subway tunnel project is feasible. A large number of test data in Practical application will play a certain guiding role to improve the design methods. Meanwhile it also can provide significance guiding for similar projects.