Author: Site Editor Publish Time: 2025-09-26 Origin: Site
In critical infrastructure projects—from underground construction and rail transit to water conservancy—the waterproofing of structural joints is paramount to long-term durability and safety. Traditional sealing methods often struggle with dynamic structural movements, long-term durability, and complex joint geometries. Water swelling sealant has emerged as an innovative and intelligent solution to these challenges. This article provides a comprehensive analysis of this advanced material, explaining its unique dual-sealing mechanism, significant engineering benefits, and the superior performance of high-grade products like the TP640 series.
Stage 1: Elastic Sealing. After application, the sealant cures to form a flexible, durable rubber-like elastomer. This provides immediate initial sealing by adhering to the joint surfaces and resisting water penetration through its inherent elasticity (with elongation at break ≥400%).
Stage 2: Expansion Sealing. When water infiltrates the joint, the hydrophilic components within the sealant absorb water molecules. This causes the material to swell significantly, with volume expansion rates ranging from 220% to 400%. This expansion sealing creates tremendous pressure against the joint walls, forming a tight, impenetrable gel barrier that can resist water pressures up to 2.5MPa.
| Parameter | 220 Type | 400 Type |
|---|---|---|
| Volume Expansion Rate | ≥220% | ≥400% |
| 7-day Tensile Bond Strength | ≥0.4MPa | ≥0.2MPa |
| Low-Temperature Flexibility | No cracks at -20°C | No cracks at -20°C |
| Expansion Retention (Long-term immersion) | ≥90% | ≥90% |
Rubber Waterstops: Passive systems that cannot compensate for significant settlement or shrinkage.
Standard Caulks/Sealants: May have poor adhesion, low durability, and lack the ability to actively seal new cracks.
Metal Waterstops: Difficult to install, especially at complex joints, and prone to corrosion.
Self-Activating Seal: The expansion mechanism automatically seals new micro-cracks that may form after installation.
Superior Adhesion: Bonds effectively to various substrates including concrete, metal, and PVC, even on slightly damp or challenging surfaces.
Ease of Application: As a single-component material, it requires no on-site mixing, reducing error and allowing for easy application with standard equipment.
Long-Term Reliability: Designed to withstand prolonged water exposure and harsh environments, ensuring a service life that can exceed 30 years.
Tunnel and Subway Projects: Sealing segment joints and construction joints.
Basements and Underground Structures: Waterproofing expansion joints, concrete joints, and penetrations.
Water and Wastewater Treatment Plants: Sealing joints in tanks, reservoirs, and channels.
Civil Infrastructure: Waterproofing joints in bridges, dams, and utility tunnels.
The TP640 product range exemplifies the advanced capabilities of modern water swelling sealant technology.
High Expansion Rate: The TP-400 type offers a very high expansion rate (≥400%), providing a greater safety margin and sealing capacity.
High-Pressure Resistance: Its ability to withstand 2.5MPa of water pressure makes it suitable for deep underground applications and high-head water structures.
Water swelling sealant technology represents a significant leap forward in waterproofing science. By combining instant elastic sealing with proactive, water-activated expansion, it provides a robust and reliable solution for the most demanding structural joints. For engineers and project managers seeking a durable, effective, and easy-to-apply waterproofing method, high-performance products like the TP640 series offer a technically advanced answer, ensuring the long-term integrity and safety of critical infrastructure.
