How to Prevent Excessive Moisture Loss in GRC Exterior Walls in High-Temperature Regions?

The High-Temperature Moisture Challenge

In high-temperature regions — Middle East, Southeast Asia, southern China summers — GRC exterior walls face rapid moisture loss during curing and service. Surface temperatures can reach 50-60°C, far above the safe curing range. Without moisture-loss control, the matrix loses capillary water prematurely, causing shrinkage cracks, reduced strength, and surface dusting.

1. Formulation-Level Control

● Add water-retention thickeners to push initial setting past 6 hours
● Use low-alkali cement with appropriate mineral admixtures to slow hydration heat
● Include internal curing agents that release water during the early hardening phase
● Adjust water-binder ratio to balance workability and moisture retention

2. Production-Level Control

● Steam curing at 25±2°C with ≥90% relative humidity for the first 24-48 hours
● Smart curing chambers with humidity and temperature sensors
● Avoid rapid temperature ramps that cause thermal stress
● Apply curing compound on exposed surfaces immediately after demolding

3. Site-Level Control

● Three-stage shade-spray-mist cycle:
　- Shade: cover panels to avoid direct sun
　- Spray: mist water 3-4 times per day
　- Mist: continuous low-pressure mist during peak heat hours
● Avoid installation during peak heat (10am-4pm); prefer early morning or evening
● Use reflective tarps during transport and storage

4. Quality Verification

● Measure weight loss to water at 24, 48, and 72 hours; should stay under 5%
● Surface moisture meter readings during curing
● Visual inspection for early crack signs

Qinglong GRC has validated this full-chain moisture-loss control at Saudi Arabia projects achieving 100% first-pass acceptance in extreme desert heat.

About Qinglong GRC — Guangdong Qinglong Construction Engineering Co., Ltd. Founded 1997 (28 years). 50+ patents. Integrated R&D, design, production, sales and construction. Contact: Mr. Song, +86 139 0259 7531. Address: 302 Card, No. 22 Dongming Road, Shiqi District, Zhongshan City.