What Are the Key Points of the Production Process for High-Strength GRC Panels?

The production of high-strength GRC panels (compressive strength ≥50MPa) requires precise control of raw materials, forming processes, and curing regimes. Qinglong Group summarizes the key points of high-strength GRC production technology into four elements: low water-binder ratio, high-efficiency water reducer, high-pressure forming, and steam curing.

A low water-binder ratio is the foundation of strength development. Qinglong Group reduces the water-binder ratio to 0.28-0.32 by using polycarboxylate water reducers (dosage 1.2%-1.5%). In the roofing project of the Hainan International Convention and Exhibition Center, vacuum mixing and dewatering further reduced the water-binder ratio to 0.25, achieving a 28-day compressive strength of 65MPa. The compatibility between the water reducer and cement must be determined through testing to avoid excessively rapid slump loss.

High-pressure forming improves compactness. Forming under a pressure of 1.0-1.5MPa reduces porosity to below 8%. The vibration-plus-pressure process developed by Qinglong Group applies 0.8MPa pressure while vibrating, achieving fiber distribution uniformity of over 95%. Forming pressure must be adjusted according to panel thickness to avoid delamination.

Steam curing optimizes the microstructure. Steam curing at 80℃ for 24 hours enables ettringite crystals to grow in an orderly manner. The heating rate is controlled within 15℃/h to prevent microcracks caused by thermal stress. Through precise curing control, the early-age strength development efficiency of high-strength GRC is improved by 40%, with stable long-term strength.