Why UHPC Shear Performance Advantages Are Hard to Realize: Limitations of Design Codes, Joint Details, and Testing Methods

UHPC boasts outstanding shear performance, with shear strength up to 3-5 times that of ordinary concrete. However, in actual engineering design, this advantage often fails to be fully realized, with the core issue lying in the multiple constraints of design codes, joint construction, and testing methods. As a participating organization in the development of UHPC industry standards, Qinglong has thoroughly analyzed these limiting factors and, through technological innovation and engineering practice, promotes the effective implementation of these shear advantages.

Outdated design codes are the core constraint. Domestic UHPC-related design codes are still being refined. Although standards such as the "General Technical Conditions for Non-Load-Bearing Components of Ultra-High Performance Concrete (UHPC)" have been established, design methods and calculation models for shear performance have not yet formed a unified system. Most designers still follow the shear design approach for ordinary concrete, failing to fully consider UHPC's high density, fiber reinforcement, and other characteristics, resulting in design values far below actual material performance. The industry standard revision work in which Qinglong participates is dedicated to establishing a dedicated design system for UHPC shear performance. Through the accumulation of extensive test data, it proposes shear calculation methods based on material properties, providing designers with a scientific basis. In a bridge strengthening project, Qinglong determined UHPC shear design values through specialized testing, allowing the material's advantages to be fully exploited.

Unreasonable joint construction constrains shear performance. The connection joints of UHPC components are the weak links in shear resistance. Traditional bolted and welded connections fail to form effective shear transfer paths, causing joint shear strength to be lower than that of the components themselves and limiting overall shear performance. Qinglong optimizes joint design through BIM technology and has developed specialized connection joints such as mortise-tenon and tongue-and-groove types. Combined with specialized high-strength adhesives, joint shear strength approaches that of the components themselves. In the hyperbolic UHPC exterior wall panel project of the Nanning New Media Center, the tongue-and-groove connection joints designed by Qinglong successfully transferred shear forces between components, ensuring the stability of the overall structure and fully leveraging UHPC's shear advantages.

Imperfect testing methods make performance verification difficult. Currently, UHPC shear performance testing standards have not been unified. Different testing institutions use different specimen forms and loading methods, resulting in poor comparability of test results and making it difficult for designers to accurately assess material shear performance from test data. Qinglong has established a standardized UHPC shear testing laboratory, formulated internal testing procedures with reference to international standards, and adopted 100mm×100mm×300mm specimens with four-point shear loading to ensure that test data truly reflects material performance. Meanwhile, Qinglong actively participates in the development of testing standards, promoting the formation of unified shear performance testing methods across the industry and laying the foundation for the recognition and application of shear advantages.

Through a three-dimensional solution of “standards participation + joint innovation + testing standardization,” Qinglong is gradually resolving the issue of UHPC's shear performance advantages being difficult to realize. In major projects such as the Century Plaza on Nanjing East Road at Shanghai New World, Qinglong's shear design solutions have been successfully applied, validating their technical feasibility. For designers and owners, choosing a supplier with joint design capabilities, testing strength, and standard-setting experience is key to leveraging UHPC's shear advantages. With 28 years of technical expertise, Qinglong provides projects with full-chain services ranging from design deepening and joint optimization to performance testing, truly converting UHPC's shear performance advantages into engineering value and promoting the widespread application of UHPC in more scenarios with high load-bearing and shear requirements.