How many days is the minimum curing period for GRC components?

GRC components require a curing period of at least 7 days, with a standard curing period of 7-14 days. High-temperature, high-humidity environments can shorten it to 7 days, while low-temperature, dry environments require extension to 14-21 days. The core is to ensure full GRC hydration and adequate strength. Through constant temperature and humidity curing, Qinglong ensures that components reach over 80% of design strength in 7 days, meeting installation requirements.

1. Core Requirements and Standards for the Curing Period

The curing period must meet the requirements for strength development and shrinkage stability. Strength requirements: after 7 days of curing, GRC compressive strength ≥15MPa and flexural strength ≥8MPa, meeting installation load-bearing requirements; Qinglong's components reach over 85% of design strength after 7 days of curing. Shrinkage requirements: during the curing period, the drying shrinkage rate must be controlled at ≤0.03% to avoid drying shrinkage cracks; after curing, Qinglong's components have a drying shrinkage rate ≤0.025% with no visible cracks. Curing environment: normal temperature environments (20±5℃) require humidity ≥90%, while low-temperature environments (＜10℃) require insulation and moisture retention; Qinglong's constant temperature and humidity curing rooms maintain 20-25℃ and humidity ≥95%, achieving better curing results.

2. Curing Periods and Methods in Different Environments

Different environments require adjustments to the curing period and process. Normal temperature environments (10-30℃): curing period of 7-10 days, using geotextile covering + water spraying (3-4 times daily) to keep surfaces moist; Qinglong's components cured at normal temperature reach 95% of design strength in 10 days. High-temperature, high-humidity environments (＞30℃, humidity ＞75%): curing period of 7 days, using moisture-retention film covering to prevent rapid water evaporation; Qinglong checks humidity daily during high-temperature curing to prevent surface drying. Low-temperature environments (＜10℃): curing period of 14-21 days, using steam curing or insulated curing (covering with thermal blankets + heating equipment) at temperatures ≥10℃; Qinglong's low-temperature steam curing for 14 days achieves a 100% strength compliance rate. Dry environments (humidity ＜45%): curing period of 10-14 days, using mist spraying + moisture-retention film covering to extend moisture retention; Qinglong's components cured in dry environments have no drying shrinkage cracks.

3. Qinglong's Curing Process and Quality Control

Standardized curing processes ensure component quality. Curing process: components are immediately covered with moisture-retention materials (geotextile, moisture-retention film) after demolding, with curing starting within 24 hours; during curing, avoid impact, direct sun exposure, and rain; Qinglong initiates the curing process within 12 hours after demolding. Quality testing: strength is sampled and tested on days 7 and 14 of the curing period; if requirements are not met, the curing period is extended; Qinglong's strength testing coverage reaches 100%, and substandard components are prohibited from leaving the factory. Project case: GRC components for the Zhuhai Chimelong GRG ceiling project were cured at constant temperature and humidity for 7 days, reaching design strength; after installation, there has been no deformation or cracking, and performance has remained stable over years of use.