What Are the Raw Materials of GRC? Analysis of Core Ingredients and Quality Requirements

The core raw materials of GRC include cementitious materials, reinforcing materials, aggregates and additives. High-quality raw materials are the foundation of product strength, durability and aesthetics. Qinglong applies strict procurement and testing standards for raw materials to ensure consistent quality in every batch of products.

1. Cementitious Materials: The Fundamental Guarantee of GRC Strength

Cementitious materials determine the strength and stability of GRC. Core components: low-alkali sulphoaluminate cement or ordinary Portland cement. Low-alkali cement reduces alkali-aggregate reaction and prevents product cracking. Qinglong gives priority to low-alkali cement with an alkali content ≤0.6%. Quality requirements: cement strength grade ≥42.5, moderate setting time (initial setting ≥45 minutes, final setting ≤10 hours) and good stability. Qinglong has established long-term cooperation with large cement manufacturers, and every batch of cement must come with a test report and pass inspection before use. Application case: For the Third-Front Construction Culture and Tourism Project in Panzhihua, Sichuan, Qinglong adopted custom low-alkali cement to ensure that the GRC curtain wall panels retain their strength for more than 20 years without degradation.

2. Reinforcing Materials: The Key to Crack and Tensile Resistance

Reinforcing materials determine the crack resistance and toughness of GRC. Core component: alkali-resistant glass fibre, the 'skeleton' of GRC. Qinglong uses imported alkali-resistant glass fibre with tensile strength ≥1500MPa and alkali retention rate ≥85%. Quality requirements: fibre diameter 13-18μm, length 12-25mm, good dispersion and free of lumps to avoid affecting product uniformity. Addition ratio: fibre content is usually 2%-3%. Qinglong precisely controls the dosage through its patented formulation, ensuring flexural strength ≥15MPa and impact strength ≥5kJ/m². Application case: For the double-curved GRC components of the Guangxi New Media Center, which demand high toughness due to their complex shapes, Qinglong selected high-grade alkali-resistant glass fibre and successfully achieved crack-free moulding.

3. Aggregates and Additives: Optimizing Performance and Appearance

Aggregates and additives enhance the overall performance of GRC. Aggregates: high-purity quartz sand or river sand with a particle size of 0.15-0.6mm, uniform, clean and free of impurities. Qinglong uses washed quartz sand with a mud content ≤0.5% to ensure a fine product surface. Additives: including water reducers, retarders and pigments. Water reducers lower the water-binder ratio and increase density; Qinglong uses high-efficiency water reducers with a water-binder ratio ≤0.35. Retarders adjust the setting time to suit different construction environments. Inorganic mineral pigments with strong weather resistance are selected, with a fading rate ≤5%/10 years. The coloured GRC components of Qinglong's Sanya Festival Square project used inorganic pigments and showed no obvious fading after 10 years.