Waterstops are core waterproof sealing elements embedded in concrete expansion joints, settlement joints and construction joints. By forming a continuous, elastic water-blocking section, they effectively cut off seepage paths of groundwater, surface water and other liquids, protecting structures from water damage, helping to maintain engineering safety and extending the design service life. Applications span tunnels, metro stations, utility tunnels, water treatment facilities, dams, locks, culverts, basements and various concrete structure joint waterproofing systems.
Based on differences in material, structure and waterproofing mechanism, waterstop products are grouped into four main categories. Each category offers specific engineering adaptability, installation characteristics and durability performance, allowing precise selection for different water pressures, movement ranges and chemical environments.
PVC Waterstop
Manufactured from polyvinyl chloride resin, it provides favorable flexibility and chemical inertness, with stable resistance to acids, alkalis and salts commonly found in groundwater. The lightweight material allows convenient handling and hot-wedge welding, helping to improve joint treatment efficiency. With notable cost-effectiveness, it is a commonly selected sealing solution for regular concrete construction joints and joints under general water pressure conditions.
Rubber Waterstop
Made from natural rubber or synthetic rubbers such as neoprene and EPDM, it is characterized by high elastic recovery and excellent tensile and compressive deformation capacity. It can continuously adhere to concrete interfaces during repeated joint opening and closing, offering reliable movement-following sealing performance under temperature variations, foundation settlement or vibration. Different rubber compounds provide options for weather resistance, oil resistance or broad temperature range suitability, making it suitable for critical movement joints in tunnels, culverts and hydraulic works.
Steel-Edged Rubber Waterstop
A composite structure where steel strips are firmly bonded on both sides of an elastic rubber core, creating a rigid-flexible combined seal. The steel edges deliver strong concrete anchorage, significantly reducing the risk of displacement or inversion during pouring and vibration, and ensuring accurate positioning. The rubber section accommodates joint movement elastically, allowing the system to handle high hydrostatic pressure, large settlement and pronounced expansion or contraction. It is frequently designated for key sealing joints in ultra-long diaphragm walls, immersed tube tunnel segments and high-grade hydraulic structures.
Water-Swellable Waterstop Strip
Prepared from hydrophilic polymer materials, it maintains a stable, compact size when dry for easy placement into designated joint grooves. Upon contact with water it actively absorbs moisture and expands, filling voids tightly and generating sustained sealing pressure. Installation does not require complex heating equipment; the strip accommodates irregular profiles and new-to-existing concrete interfaces. It is widely used for supplementary waterproofing of construction joints, sealing of precast element joints, and leak repair, serving as a flexible auxiliary water-sealing component.
