How to Prevent Rapid Moisture Evaporation in GRC Exterior Walls in High-Temperature Regions: Key Technologies and Practical Measures

In construction projects in high-temperature regions, GRC exterior wall materials are widely used for their combined decorative and structural advantages, but excessively rapid moisture evaporation often leads to problems such as component cracking and reduced strength. As an industry leader with 28 years of full-chain experience in UHPC/GRC/GRG/GRP materials, Qinglong Group, drawing on project practice in high-temperature regions such as South China and Southeast Asia, has formed a systematic solution covering material formulation optimization, construction process innovation, and intelligent curing system construction, providing professional technical support for designers and owners.

I. Core Challenges of Moisture Evaporation in GRC Materials under High-Temperature Environments

High-temperature environments with intense radiation accelerate the dual loss of free water and bound water in GRC substrates. When the moisture evaporation rate exceeds the demands of cement hydration, three major problems are likely to arise: first, rapid surface drying forms shrinkage cracks, affecting appearance and durability; second, insufficient hydration leads to inadequate strength development, reducing structural load-bearing capacity; third, increased defects in the interfacial transition zone weaken the bond between glass fibers and the cement matrix. Taking a commercial complex project in Saudi Arabia as an example, surface temperatures during summer construction can reach 65°C, and the cracking rate of GRC components under traditional processes was as high as 12%, while the adoption of Qinglong's specialized technology reduced it to below 1.5%.

II. Material System Optimization: Controlling the Moisture Evaporation Rate at the Source

Qinglong achieves anti-evaporation design at the material level through three technical pathways: first, it developed a high-temperature-specific GRC formula incorporating a 0.03% nano calcium carbonate modifier to refine cement particle gradation, making hydration products denser and reducing the moisture evaporation rate by 20%; second, it adopts a composite fiber reinforcement system, mixing ordinary glass fibers with basalt fibers at a 3:1 ratio to enhance the crack resistance of the substrate, achieving flexural strength above 22MPa; finally, it optimizes the mixing water-cement ratio to the 0.38-0.42 range, combined with a specialized retarding water reducer, extending the initial setting time to over 4 hours and reserving ample operating windows for high-temperature construction. These technologies have been authoritatively certified under the Technical Standard for Building Application of Glass Fibre Reinforced Cement (GRC) (JGJ/T423-2018).

III. Construction Process Innovation: Dynamically Regulating On-Site Moisture Balance

For high-temperature construction scenarios, Qinglong has innovatively launched the "Three-Stage Temperature-Controlled Construction Method": in the prefabrication stage, constant temperature and humidity curing kilns are used to maintain a 25°C/85% humidity environment for 7 days of curing; in the transportation stage, special vehicles equipped with mist spraying systems ensure that the surface moisture content of components is not lower than 15%; in the installation stage, the "install in the morning, cure in the evening" operation mode is implemented—installation stops after 16:00 each day, components are immediately covered with water-retentive breathable film, and the intelligent spray system is activated to replenish water every 2 hours. In the Penang Airport expansion project in Malaysia, this process raised the first-pass acceptance rate of GRC exterior wall panel installation to 98% and shortened the construction period by 18 days compared with traditional methods.

IV. Intelligent Curing System: Full Life-Cycle Moisture Management

Qinglong's self-developed GRC intelligent curing system monitors data in real time through temperature and humidity sensors embedded in components, and combines BIM technology to dynamically adjust curing plans. The system has three built-in modules: the moisture evaporation prediction module provides early warning 48 hours in advance based on local meteorological data; the automatic water replenishment module precisely replenishes water through IoT-controlled misting nozzles; and the strength development tracking module predicts 28-day strength by correlating laboratory data. The system has been successfully applied in projects such as the Nanning ASEAN Culture and Art Center, raising the 28-day strength compliance rate of GRC components in high-temperature environments to 100%.

As a national high-tech enterprise and a participant in GRC industry standard-setting, Qinglong has always been committed to its mission of "creating beautiful architecture," transforming 28 years of engineering experience into technical advantages. Its full-chain service capability from material R&D to construction implementation has not only solved the moisture evaporation challenge of GRC exterior walls in high-temperature regions, but also driven the industry toward green and intelligent construction. Looking ahead, Qinglong will continue to focus on UHPC/GRC/GRG/GRP material innovation, providing more cost-effective solutions for building projects in high-temperature regions worldwide.