Experimental study on mechanical properties of novel truss-type steel fiber reinforced concrete prefabricated plate

Traditional prefabricated concrete plates commonly exhibit several inherent deficiencies that severely restrict their practical application, including low cracking resistance under tensile stress, insufficient ductility to accommodate large deformations, pronounced stress concentration at critical connection zones, and an over-reliance on temporary supports during on-site erection, all of which collectively undermine both structural safety and construction efficiency. In response to these persistent challenges, this study proposes a Novel Truss Steel Fiber-Reinforced Concrete prefabricated plate (N-SFRC plate), which is developed through a material-structure integrated design strategy that systematically optimizes both constituent materials and internal configuration. The core innovation lies in two complementary modifications: firstly, the conventional steel bar trusses are replaced by a novel truss system consisting of upper concrete top chord plates and steel pipe web members, which provides more efficient load transfer and enhanced spatial stability; secondly, the ordinary C30 concrete is substituted with steel fiber-reinforced concrete, which substantially improves tensile strength and post-cracking behavior. This synergistic design is intended to significantly improve the mechanical performance of the prefabricated plates throughout the construction phase, particularly by reducing the need for temporary props. To validate the proposed concept, monotonic static loading tests were carried out on four full-scale specimens, with careful monitoring of load-displacement responses, strain distributions, and crack propagation patterns to comprehensively assess their mechanical response and failure characteristics. The experimental results demonstrate that the N-SFRC plate exhibits markedly superior bearing capacity, enhanced ductility, and better damage controllability when compared with conventional counterparts. More importantly, the failure mode transitions from the typical brittle crushing of ordinary concrete to a progressive gradient release-multi-core energy dissipation mechanism, which effectively postpones catastrophic collapse and greatly improves both the ductility and damage tolerance of the top chord under severe loading. Consequently, the proposed design substantially enhances the support-free capacity of the prefabricated plates during assembly, thereby streamlining the construction process and reducing labor and equipment costs, and it offers a promising new direction for the development of high-performance prefabricated components suitable for modern accelerated bridge construction and similar applications.