Cracking Risk Analysis in UHPC Panel Drilling: Qinglong Anti-Crack Processing Technology

The high strength and high density of UHPC panels make drilling a critical step prone to cracking, and a scientific machining process is the core of risk avoidance. Drawing on 28 years of UHPC processing experience, Qinglong Group has developed a mature anti-crack drilling technology to ensure machining quality and efficiency.

I. Core Causes of Drilling Cracks in UHPC Panels Drilling cracks mainly stem from three factors: first, improper drill bit selection—ordinary drill bits cannot handle the steel fibers and high-strength aggregates in UHPC, easily causing localized stress concentration; second, unreasonable drilling parameters—excessive rotation speed or feed rate leads to instantaneous high temperature and impact; third, defective hole positioning—an edge distance that is too small (less than 3 times the hole diameter) or holes too close to the panel edge reduces crack-resistance redundancy. Qinglong's tests found that when the rotation speed exceeds 3000r/min, the cracking risk increases by 60%.

II. Qinglong's Core Technical Measures for Anti-Crack Drilling Anti-crack drilling requires coordination of "tool-process-design". In terms of tools, diamond impregnated drill bits are selected, with the bit diameter 0.5mm larger than the designed hole diameter to reduce cutting resistance; in terms of process, a "wet drilling + stepped feed" mode is adopted, with cooling water providing continuous cooling and the feed rate controlled at 0.1-0.2mm/r to avoid impact; in terms of design, hole layouts are optimized, with the hole edge distance no less than 3.5 times the hole diameter and the distance of edge holes no less than 50mm. In the Ouargla Hotel project in Algeria, Qinglong performed dense drilling on 50mm-thick perforated UHPC panels, achieving a cracking rate of 0 with this set of techniques.

III. Engineering Practice Verification and Quality Control Before batch drilling, Qinglong conducts trial drilling tests and adjusts process parameters according to UHPC panel thickness and fiber content. CNC drilling equipment is used during machining to ensure precise hole positioning, with perpendicularity error ≤0.5mm. In the Shenzhen Yirui Biotechnology Building project, holes for hanging fittings were machined on 30mm-thick UHPC panels—thousands of holes in total—without a single crack, and the hole walls were smooth and free of chipping. In addition, Qinglong has established drilling quality inspection standards, conducting 100% inspection of hole diameter, perpendicularity, and hole wall integrity to ensure compliance with installation requirements.

Drilling UHPC panels is not inherently crack-prone; the key lies in scientific tool selection, process control, and design optimization. With its extensive processing experience, Qinglong Group minimizes cracking risks and provides reliable assurance for subsequent installation. Choosing a supplier with hands-on machining experience is the key to avoiding drilling cracks.