Application of Fracture Mechanics to Design of SFRC Tunnel Linings and Development of Strain-Hardening Cementitious Composites

The application of fracture mechanics to the design of steel-fiber-reinforced concrete (SFRC) tunnel linings and the development of strain-hardening cementitious composites is presented. In the first part of the paper, a recently established design provision on the estimation of the load carrying capacity of SFRC tunnel linings is briefly introduced. The design method is based on the fracture mechanics of concrete. Existence of a crack and transmission of stress by fibers are considered in the estimation of the maximum resultant forces of the critical cross-section. this study, validity of the current design method is verified, and possible improvements of the design method are proposed. the second part of the paper, we present an analytical model for fracture analysis of strain-hardening cementitious composites. Such an analytical tool is necessary for the evaluation of the performance of new materials used in structural members. Both multiple and localized cracking, which are characteristic of this class materials, are represented in the model. A plasticity-based modeling 1345 method is distributed multiple cracking, discrete modeling is the localized cracks. Fracture tests strain-hardening composites are analyzed, and fracture energy is compared with reported experimental results. 1 ._,.JL...,...., ............ ,L/I..,.,.., of concrete has been extensively more to understand the fracture behavior of concrete loads. The governing mechanisms have been mode one crack growth phenomena. mechanisms, their modeling, methods has to some extent -t-... ,..,,,.~,.,,.°' mechanics of concrete have now entered second such as, establishment of the analysis tools concrete structures including tensile and compressive of fracture mechanics for design and development new cementitious materials based on fracture mechanics and micromechanics. The paper is devoted to the application design of steel-fiber-reinforced concrete (SFRC) tunnel linings. A established Japanese design provision for SFRC linings, which is based on the fracture mechanics of concrete, is briefly introduced, and to be improved are shown. Finally, a modified design method proposed. The second part of the paper is devoted to a new class of - pseudo strain-hardening cement-based composites. Noting that modeling is an essential part of the development of new materials, we a fracture mechanics-based model for the .. , ......... TL. hardening composites. The model is used to effect and specimen size on fracture energy reported experimental data.