What Problems and Potential Risks Can Non-Standard Reinforcement Around Screw Hole Edges in Precast Components Cause

The Invisible Killer of Building Safety: A Millimeter-Level Difference in Screw Hole Edge Reinforcement Technology Can Determine a Project's Century-Long Foundation.

In the application of new decorative building materials such as UHPC/GRC/GRG/GRP, the treatment of component connection joints is often the critical factor determining project quality. As an industry leader with 28 years of experience in detailed design, manufacturing, and construction, Qinglong Group has found, while undertaking landmark projects at home and abroad, that non-standard screw hole edge reinforcement has become a core hidden danger affecting component safety and durability. From an engineering practice perspective, this article provides an in-depth analysis of the chain reactions and systemic risks that this concealed defect may trigger.

### I. Structural Load-Bearing Failure: The Chain Reaction from Local Cracking to Overall Collapse

In application scenarios such as curtain walls and decorative lines, the screw hole areas of UHPC/GRC components must withstand multiple forces including wind loads, self-weight, and thermal stress. If the reinforcement process is non-standard—for example, if fiberglass mesh or steel rebar frameworks are not installed as required by the design—the tensile strength of stress concentration areas will drop by more than 40%. In a commercial complex project, because the screw holes of a GRG ceiling were not given rounded corner treatment, radial cracks appeared just 3 months after installation, and the ceiling ultimately had to be demolished and rebuilt. During the detailed design stage, Qinglong Group used BIM technology to simulate stress distribution and adopted a “bell mouth + ring reinforcement” process, improving the crack resistance of similar components by 200%.

### II. Durability Degradation: Accelerated Aging Mechanisms Under Environmental Erosion

If screw holes in the GRP daylighting roofs of seaside buildings are not properly sealed, “capillary water absorption channels” will form, causing oxidation and corrosion of the internal glass fibers. Testing by Qinglong's technical team on a hotel project in Malaysia found that screw holes without reinforcement treatment showed fiber exposure after just 18 months in a salt spray environment. However, using Qinglong's patented “ternary sealing reinforcement system” (UHPC embedded sleeve + butyl rubber + stainless steel washer), the weather-resistance life of components can be extended to more than 50 years—a process that has been incorporated into the Technical Standard for Building Applications of Glass Fiber Reinforced Cement (GRC) (JGJ/T423-2018).

### III. Loss of Installation Precision: Triggering Systemic Construction Errors

The installation precision of special-shaped UHPC exterior wall panels for museums must reach ±2mm; if screw hole positioning deviation exceeds 5mm, assembly stress will develop in adjacent panels. In the Nanjing East Road Century Plaza renovation project, Qinglong controlled on-site installation errors to within 1mm through 3D laser scanning pre-positioning combined with factory-prefabricated reinforcement inserts—a technology that won the AALBORG WHITE Cup UHPC Construction Engineering Innovation Award. In contrast, at an exhibition center project, displacement of screw hole reinforcement inserts caused 300 GRC cladding panels to be reworked, resulting in direct economic losses of over one million yuan.

### IV. Surging Life-Cycle Costs: A Quantitative Analysis of Hidden Costs

According to statistics from Qinglong's corporate database, after-sales maintenance costs caused by screw hole edge process defects account for an average of 8-12% of total project cost. Repairs to an airport GRG ceiling caused by screw hole corrosion cost as much as 480 yuan per square meter—six times the cost of the standard process. As a national “Specialized, Refined, Distinctive, and Innovative” enterprise, Qinglong has compressed such risk costs to below 2% through full-chain quality control of “design-production-installation.” The industry standard it led in compiling, General Technical Conditions for Non-Load-Bearing Components of Ultra-High Performance Concrete (UHPC), is establishing stricter reinforcement process specifications.

The safety defenses of architectural decoration are often hidden in invisible details. Qinglong Group's 28 years of engineering practice show that standardized treatment of screw hole edge reinforcement is not only a reflection of material performance, but also a testament to the company's commitment to its mission of “creating beautiful architecture.” For designers and owners pursuing century-long projects, choosing UHPC/GRC/GRG/GRP suppliers with full-chain technical capabilities is the fundamental way to avoid risks at the source. After all, on the scale of building safety, no technical detail can be compromised.