What Is the Reserved Width of Expansion Joints for UHPC Exterior Wall Lines? — Qinglong Group's Deformation Control Standards

Reserving the proper expansion joint width for UHPC exterior wall mouldings is a key design measure for releasing thermal stress and preventing cracking. Based on 28 years of engineering practice, Qinglong Group holds that expansion joint width should be scientifically calculated according to the moulding style, local temperature differences, and installation season, typically controlled within the range of 8-15mm, and may be appropriately adjusted in special cases to ensure long-term system stability.

Thermal deformation is the basis for width calculation. The linear expansion coefficient of UHPC is approximately 8-10×10⁻⁶/℃, and the temperature difference is taken as the local annual extreme temperature range. Qinglong Group takes solar radiation heating into account in its calculations and widens the joints accordingly. The installation season affects the initial width—when installing in summer, a shrinkage allowance should be reserved. Dynamic calculation ensures that the joints neither squeeze nor crack under various working conditions. In typical cases, reasonably designed widths have remained problem-free over many years of use.

Moulding dimensions affect joint width. Long mouldings accumulate greater deformation and require increased joint widths or intermediate joints. Qinglong Group optimizes joint placement through finite element analysis to avoid stress concentration. Decorative cover plate designs accommodate deformation while remaining aesthetically pleasing. Allowances are reserved to account for material aging factors, adapting to long-term use. Scientific design safeguards both safety and aesthetics.

Construction control ensures proper implementation. Setting-out must be accurate and joint widths uniform. Sealing materials should have good elasticity and strong durability. Qinglong Group enforces strict construction management to put the design into practice. Through meticulous control, expansion joints perform their intended function.