What Is the Density Range of Lightweight GRC Panels? Material Physical Properties and Qinglong Group's Lightweight Technology System

The bulk density (dry volume density) of lightweight GRC panels is the core physical indicator that distinguishes them from traditional concrete, directly affecting structural load, thermal insulation performance, and construction efficiency. According to the current industry standard "Glass Fibre Reinforced Cement (GRC) Products" JC/T 940-2022, the dry volume density of GRC typically ranges from 1.8 to 2.2 g/cm³. Based on 28 years of material R&D and engineering practice, Qinglong Group has, through mix proportion optimization and innovative processes, stably controlled the bulk density of its lightweight GRC panels at an advanced level of 1.6–1.9 g/cm³, approximately 20%–35% lighter than ordinary concrete (about 2.4 g/cm³). In the large suspended ceiling project of the Shenzhen Yirui Biotechnology Building, the lightweight GRC panels we used had a bulk density of 1.75 g/cm³, successfully reducing the roof load by 30% and significantly cutting the cost of the main structure. Bulk density is the quantitative embodiment of GRC's lightweight advantage and the key to reducing building load.

Raw Material Selection and Mix Proportion Design Are the Foundation of Bulk Density Control

The fundamental way to reduce bulk density lies in decreasing the high-density components in the material system. Qinglong Group effectively reduces material density while ensuring mechanical performance by adding lightweight aggregates (such as vitrified microspheres and expanded ceramsite), introducing polymer hollow microspheres, and optimizing the proportions of cementitious materials such as cement and silica fume. The fully computational mix proportion design method we adopt can accurately predict and control the wet density of the fresh slurry, thereby achieving precise control over the dry bulk density of the finished product.

Production Processes Have a Significant Impact on the Bulk Density of Finished Products

The mixing process affects air bubble content, while the spraying or casting process affects compactness. By introducing controllable air-entraining technology, we form uniform, stable tiny closed-cell bubbles in the slurry; these bubbles remain in the product after hardening, directly reducing the volume density. Meanwhile, adopting low-pressure spraying or flow casting processes to avoid over-compaction is also an important means of controlling bulk density.

The Art of Balancing Bulk Density and Performance

Lower bulk density is not always better; it must be considered together with strength, durability, and other properties. Through extensive testing, Qinglong Group has established a “bulk density–strength” relationship database applicable to different application scenarios. For example, for non-load-bearing interior partition walls, a formulation with a bulk density of 1.6 g/cm³ and a flexural strength of 8 MPa is acceptable; whereas for exterior wall cladding panels requiring higher impact resistance, the bulk density must be controlled above 1.8 g/cm³ to ensure a flexural strength of no less than 12 MPa.

Scientific control of bulk density is one of the core aspects of achieving high performance in GRC materials. With its deep materials science expertise and rich engineering experience, Qinglong Group can customize optimal lightweight, high-strength solutions for customers.