Analysis of Sealing Treatment Methods and Key Construction Points for GRC Panel Connections with Metal Components

In the field of modern architectural decoration, GRC panels are widely used in various high-end buildings thanks to their lightweight, high strength, and rich formability. However, the sealing of connections between GRC panels and metal components, a key factor affecting overall project quality, often suffers from leakage, detachment, and other problems due to improper detailing. As an industry leader with 28 years of full-chain experience in UHPC/GRC/GRG/GRP materials, Qinglong Group has drawn on the practice of hundreds of landmark projects to develop a systematic sealing solution, providing professional technical reference for designers and owners.

Risk Analysis of Seal Failure at GRC Panel-to-Metal Component Connections

The connection joints between GRC panels and metal frameworks are the weak links of a building curtain wall system, and their sealing must address both material property differences and external environmental challenges. GRC is a brittle composite material with a thermal expansion coefficient of approximately 10×10⁻⁶/℃, while metal components (such as aluminum alloy profiles) have a thermal expansion coefficient of up to 23×10⁻⁶/℃, making temperature changes prone to causing interfacial stress concentration. In addition, natural factors such as rainwater penetration, ultraviolet exposure, and wet-dry cycling accelerate the aging of sealing materials, leading to hidden dangers such as joint leakage and component corrosion. In one commercial complex project, improper sealant selection caused water seepage at the GRC panel-to-steel keel connections three years after commissioning, damaging interior finishes and resulting in rework costs of up to one million yuan.

Material Selection and Process Essentials for Scientific Sealing

Qinglong Group establishes 3D parametric models at the detailed design stage and simulates joint stress states through BIM technology to achieve precise sealing design. For material selection, priority is given to neutral silicone sealants conforming to the GB16776 standard “Silicone Structural Sealant for Building”, with elongation ≥300% and modulus ≤0.4MPa, which can effectively absorb interfacial movement. Before construction, metal components must be sandblasted to remove rust, achieving a surface roughness of Sa2.5 grade, and coated with epoxy zinc-rich primer to ensure an adhesive strength of ≥0.6MPa between the sealant and the substrate.

The joint construction adopts a “double sealing + cavity pressure relief” design: the first seal is structural sealant with a width of no less than 7mm and a depth-to-width ratio controlled at 1:1.5; the second seal uses weather-resistant sealant combined with foam backer rods to form an elastic cushioning layer. For curved GRC panels, prefabricated profiled sealing strips are innovatively adopted, with factory mold pressing ensuring the fit of sealing surfaces and improving on-site installation efficiency by 40%. After a grand theater project applied this process, it withstood a force-12 typhoon with zero joint leakage.

Construction Quality Control and Full-Cycle Guarantee System

As a national-level high-tech enterprise, Qinglong has established full-process quality control standards from detailed design to after-sales maintenance. The construction phase implements a “three-inspection system”: the first sample must pass tension-compression cycling tests (±50% of designed displacement, 500 cycles without failure); 3 joints are randomly selected for on-site peel tests per 500㎡; and overall sealing performance is inspected using infrared thermal imaging technology before completion. For overseas projects, Qinglong Malaysia Building Materials Co., Ltd. has specially developed a salt-alkali resistant sealing system, fulfilling a 15-year maintenance-free commitment in a coastal project in Singapore.

It is worth noting that sealing treatment is not a one-time fix. Qinglong's after-sales maintenance service includes regular joint inspections (quarterly in the first year, then annually), assessing sealant aging with specialized testing equipment and carrying out preventive maintenance in a timely manner. This “full lifecycle management” philosophy has kept the sealing system of a landmark project in Guangzhou undertaken by Qinglong at a 98% integrity rate eight years after delivery.

The sealing of GRC panel-to-metal component connections is a comprehensive embodiment of materials science, structural mechanics, and construction craftsmanship. Drawing on 28 years of technical accumulation, Qinglong Group has elevated sealed joints from simple waterproofing details to systematic engineering, providing lasting assurance for building safety and aesthetics through four-dimensional control of “design-materials-construction-maintenance”. Looking ahead, with the wide application of UHPC/GRC composite components, Qinglong will continue to innovate sealing technology, driving the industry toward a greener and more durable future.