Recently, the National Standards Committee announcedGB/T 18445-2025 'Waterproof Materials Based on Cement and Reactive Chemicals', which will officially take effect on January 1, 2026. GB 18445, first issued in 2012, has been widely used for over a decade. This revision was conducted by the Building Materials Industry Technology Supervision Research Center, Tongji University, China Inspection Group, Suzhou Company, Dongfang Raincoat, Beixin Waterproof, Kexun, and many other enterprises. The new standard comprehensively optimizes terminology definitions, technical requirements, and testing methods to enhance product quality and test standardization, supporting high-quality industry development.

Cement-Based Reactive Chemical Waterproofing Materials
Product Description

Cement-based reactive chemical waterproofing materials are specially designedpowdered cementbased on cement, manufactured by adding special reactive additives to produce deep gray powder materials.

The core technology lies in its unique reactive crystallization mechanism. When this material contacts water, the reactive chemicals act as a medium, penetrating into the micro-pores and capillaries within the concrete structure.

During penetration, these reactive chemicals react with unhydrated cement particles in the concrete to form insoluble crystalline compounds such as calcium silicate hydrate (CSH) and calcium carbonate. These compounds not only fill internal voids and cracks but also effectively block further water infiltration, achieving long-lasting waterproofing results.

In addition, thiscement-based reactive chemical waterproofing materialemploys a multi-porous structural design, allowing reactive chemicals to penetrate deeper into the concrete interior. As water continues to infiltrate, more reactive chemicals continuously undergo reactions, generating additional crystalline substances, further increasing the concrete’s density and enhancing its anti-permeability performance.

In summary, cement-based reactive chemical waterproofing materials achieve effective waterproofing through their unique reactive crystallization technology, preventing water from penetrating concrete structures, protecting them from environmental degradation, and significantly extending their service life.

Working Principle

Cement-based reactive chemical waterproofing materials are high-performance waterproof materials composed of cement, reactive chemicals, and special additives. Their working principles mainly involve the following aspects:

Strong Permeability:The reactive chemicals in the material possess strong permeation capabilities, capable of deeply penetrating into the micro-pores and capillaries within concrete, forming tight bonds with the concrete matrix.

Crystallization Upon Contact with Water:When the reactive chemicals contact water, they undergo a chemical reaction, producing insoluble crystalline substances. These crystals effectively fill voids and micro-cracks within the concrete, blocking water pathways and achieving waterproofing goals.

High Water Pressure Resistance:The special additives in the material enhance the density and anti-permeability of the concrete, maintaining excellent waterproof performance even under high water pressure conditions.

Key Characteristics

Long-Term Durability:Due to the continuous reaction between reactive chemicals and water, new crystalline substances are formed over time. This ensures long-term stability of the waterproofing effect. Even in harsh environments, it maintains good waterproofing performance.

Environmental Friendliness:These materials are primarily based on cement, are non-toxic and harmless, and do not pollute the environment. Moreover, their production process complies with environmental standards, promoting sustainable development in the construction industry.

Easy Application:The material can be directly applied or sprayed onto the surface of concrete, making installation simple and fast, significantly shortening construction periods. It also provides excellent coverage and waterproofing performance on complex shapes and detailed joints.

Wide Applicability:Cement-based reactive chemical waterproofing materials are suitable for various concrete structures, including basements, water tanks, reservoirs, and tunnels. They offer excellent adaptability for both new construction and repair projects.

Application Areas
Applications

Cement-based reactive chemical waterproofing materials have widespread applications across multiple sectors. Their superior waterproofing performance and long-term durability make them the preferred choice fortunnel construction, dams, waterwaysand other major infrastructure projects. In modern industrial facilities such aspower plants, nuclear power stations, and closed cold storage facilities, these materials play a crucial role in ensuring safe and reliable operation.Cement-based reactive chemical waterproofing materialsalso perform vital functions, guaranteeing the long-term safety and stability of these facilities under extreme environmental conditions.

Furthermore, in transportation infrastructure such asunderground railways, elevated bridges, road overpasses, and retaining walls, these materials demonstrate their unique advantages. They effectively prevent water from damaging concrete structures, ensuring long-term stability and safety of these critical transport systems.

In the building sector—whether for industrial production facilities or residential buildings—basements, floors, and wet areas like bathrooms, these materials provide durable and reliable waterproof protection. Additionally, for repair and leak-sealing work on concrete structures, cement-based reactive chemical waterproofing materials offer an efficient and practical solution.

In conclusion, cement-based reactive chemical waterproofing materials, leveraging their outstanding waterproofing performance and wide-ranging applications, play an irreplaceable role in construction and infrastructure development. They not only enhance engineering quality and safety but also make significant contributions to modern society's construction and progress.

Advantages in Waterproof Engineering
Key Benefits:

✓ Significantly Enhanced Waterproofing Performance:Compared to traditional waterproofing methods, cement-based reactive chemical waterproofing materials can significantly improve the anti-permeability of concrete. Tests show that treated concrete specimens can see improvements in anti-permeability by several to even tenfold.

✓ Reduced Maintenance Costs:Due to their excellent durability and resistance to aging, these materials greatly extend the service life of waterproofing projects. This reduces maintenance frequency and costs over the long term.

✓ Improved Construction Quality:Beyond enhancing waterproofing performance, the use of these materials also improves other concrete properties such as strength and abrasion resistance, contributing significantly to overall project quality.

✓ Expanded Application Scope:With continuous technological advancement and ongoing improvements in material performance, the application scope of cement-based reactive chemical waterproofing materials continues to grow. Beyond traditional construction, they are now being applied in water conservancy, transportation, municipal infrastructure, and specialized environments such as marine engineering.

Final Summary and Outlook

Cement-based reactive chemical waterproofing materials demonstrate remarkable potential and advantages in construction waterproofing due to their unique characteristics—strong permeability, high water pressure resistance, and crystallization upon contact with water. With ongoing technological innovation and evolving market demands, we are confident that these high-performance materials will play an increasingly important role in the future. To further promote their development and application, the following areas merit deeper research and exploration:

✓ In-depth Study of the Relationship Between Composition and Performance:Through systematic research into how each component affects performance and their mutual interactions, we can optimize formulation design, improve product performance, and reduce manufacturing costs.

✓ Development of Multi-Functional Cement-Based Reactive Chemical Waterproofing Materials:To meet diverse application scenarios and market demands, develop composite materials with multiple functions such as enhanced durability, self-healing capability, and thermal insulation.

✓ Strengthen R&D on Construction Techniques and Quality Control:Addressing potential issues in real-world construction and optimizing construction techniques while establishing a comprehensive quality control system to ensure reliable construction quality and waterproofing effectiveness.

✓ Promote Green and Sustainable Development:Integrate environmental protection concepts throughout product R&D and production processes, promoting the use of renewable resources and eco-friendly raw materials, reducing energy consumption and emissions, and driving the construction industry toward green and sustainable development.

✓ Expand International Exchange and Cooperation:Strengthen collaboration with international peers to introduce advanced technologies and management experience, enhancing China’s global competitiveness and promoting the worldwide application and popularization of cement-based reactive chemical waterproofing materials.

Source: China Construction Waterproofing, Lianxi