Why UHPC's Shear Performance Advantages Are Difficult to Reflect in Design: Cause Analysis and Discussion of Solution Paths

Amid the wave of technological innovation in building materials, ultra-high performance concrete (UHPC) has become an industry focus for its outstanding mechanical properties. In particular, its shear strength—3 to 5 times higher than that of traditional concrete—gives it the theoretical potential to change engineering design logic. In actual projects, however, this performance advantage often remains stuck "on paper": designers hesitate, contractors struggle with execution, and owners harbor cost concerns—together forming barriers to the application of UHPC's shear performance. As an industry participant with 28 years of deep engagement in the UHPC/GRC/GRG/GRP materials field, Qinglong Group has gradually revealed, through whole-chain practical experience, the underlying logic behind this contradiction and the path to breaking the impasse.

### 1. Cognitive Gap: From Laboratory Data to Engineering Practice UHPC's shear performance advantage is remarkable in laboratory settings: its three-dimensional reinforcement system, formed by randomly distributed steel fibers, effectively suppresses crack propagation and transfers shear forces. In actual engineering, however, the primary obstacle designers face is the dual dilemma of missing standards and insufficient case studies. Current concrete structure design codes have not yet established a unified standard for UHPC shear calculation models, and most design institutes still follow traditional concrete design thinking, making it hard to translate technical advantages into design language. In a provincial convention and exhibition center project, the original design adopted a traditional concrete deep beam scheme; even though it was known that UHPC could reduce cross-section thickness by 40%, the lack of mature design precedents led to a conservative option being chosen in the end. This phenomenon of "knowing the advantage yet not daring to use it" reflects the industry's lagging awareness of new materials.

### 2. Technical Bottleneck: The Tug-of-War Between Process Complexity and Cost Sensitivity The realization of UHPC's shear performance depends heavily on precise control of material proportions and construction techniques. Its steel fiber content must be strictly controlled within the 2-5% range: insufficient vibration easily causes fibers to clump, while excessive vibration results in oriented fiber distribution—both weaken the shear effect. During the construction of UHPC curtain wall connectors for a landmark project, deviations in on-site mixing parameters caused the shear strength dispersion of the first batch of components to reach 15%, forcing rework. Meanwhile, UHPC raw material costs are 3-4 times those of ordinary concrete. Although comprehensive benefits can be optimized by reducing structural self-weight and shortening construction periods, owners tend to focus more on initial investment, and this cost sensitivity further narrows the application space of the shear advantage.

### 3. Lack of Coordination: The Information Asymmetry Dilemma Along the Industry Chain In UHPC applications, the disconnect among designers, contractors, and material suppliers is a widespread pain point. Designers lack a deep understanding of UHPC construction techniques and often propose shear detailing requirements beyond current processing capabilities; contractors have insufficient command of new material properties, and traditional construction habits lead to performance losses; material suppliers, with limited engineering experience, struggle to provide targeted shear solutions. In a commercial complex project, Qinglong Group found that by establishing a tripartite joint technical team of "design-production-construction" and using BIM technology for digital simulation of shear joints, the compliance rate of the actual shear performance of UHPC components could be raised to 98%, an improvement of 23 percentage points over traditional collaboration modes.

### 4. The Path to Breaking Through: Building an Ecosystem for Applying UHPC Shear Performance Solving the application challenges of UHPC's shear performance requires systematic change across the entire industry chain. At the technical level, industry standard-setting should be accelerated and performance-based design methods established; for example, the "General Technical Conditions for Ultra-High Performance Concrete (UHPC) Non-Load-Bearing Components," compiled with Qinglong's participation, has incorporated shear performance grading indicators. At the practical level, an integrated service model of "material supplier + design consultation" should be promoted, optimizing shear detailing through in-depth design to reduce construction difficulty. A municipal bridge project adopted the UHPC shear connector system provided by Qinglong, reducing joint dimensions by 50% while raising construction efficiency by 40% through standardized production. In terms of cost control, a "local UHPC reinforcement" strategy can be adopted, using UHPC material only in high-stress zones to balance performance and cost.

The release of UHPC's shear performance value is essentially a dual breakthrough—a material revolution combined with a shift in industry thinking. As the standards system improves, technical processes mature, and industry chain collaboration deepens, this "advantage hidden in the laboratory" will surely be transformed into core momentum driving the upgrading of the construction industry. Qinglong Group's 28 years of technical accumulation show that only by forming a closed loop of material performance, design logic, and construction techniques can UHPC's shear potential be truly activated, injecting new possibilities into the structural safety and form innovation of buildings.