New amendment to the Code of Practice on the design of fiber-reinforced concrete structures with non-steel fibers

Abstract

Introduction. The acting version of the Code of Practice on the design of fiber-reinforced concrete structures with non-steel fibers SP 297.1325800.2017 “Fiber-reinforced concrete structures and precast products with non-steel fibers. Design rules” contain no instructions for the strength calculation of circular cross-sections with and without reinforcement under the action of bending moments and longitudinal forces. In addition, the current version provides no instructions for determining the subclass index of fiber-reinforced concrete with non-steel fibers using the residual axial tensile strength, as well as those for calculating the fire resistance of fiber-reinforced concrete structures. The absence of these provisions leads to significant difficulties in the design of individual structures made of fiber-reinforced concrete, which increases material and time expenditures.Aim. To improve the system of urban planning activities in terms of clarifying and supplementing the current regulatory documents for the design of fiber-reinforced concrete structures with non-steel fibers.Methods and materials. A draft of amendment No. 2 to SP 297.1325800.2017 was developed taking into account contemporary requirements, as well as the latest scientific research. In particular, the results of the research work concerning the fire resistance of structures made of fiber-reinforced concrete with non-steel fibers, performed by the Research Institute of Concrete and Reinforced Concrete (NIIZHB) named after A.A. Gvozdev in 2020, were taken into account. In addition, the experience of the authors and design organizations, gained during the practical application of this Code of Practice, was analyzed in order to clarify its provisions for the convenience of users.Results. The results of the work involve the draft of the amendment No. 2 to SP 297.1325800.2017, whose positions include new calculation techniques, as well as the refinements of existing calculation and construction methods. The developed amendment has passed public discussions, as well as the necessary expertise, and is being prepared for approval and enactment.Conclusion. Positions of amendment No. 2 to SP 297.1325800.2017 “Fiber-reinforced concrete structures and precast products with non-steel fibers. Design rules” can be used to develop reliable design solutions for these structures, including the achievement of a certain economic effect.