Waterstop plays an important role in waterproofing a concrete structure, especially joints, the weakest part which is liable to leakage of water or chemical liquids. So water stops are designed as a fluid-tight diaphragm embedded in or running along the joints to solve these problems. Manufactured from various materials in a range of shapes and sizes.
The water stops are perfect for various types of applications as shown below
1- Water and sewage disposal projects.
2- Liquid containments.
3- Dams, channels, tunnels and tanks.
4- Box culverts and locks.
5- Primary and secondary containment structures.
6- Bridges and decks abutments.
7- Wall and slabs.
8- Basements and foundations, etc.
Types
1- PVC Waterstops
PVC is used to waterproof construction joints by embedding it in both sides of the joint to create a physical barrier. A variety of widths, thicknesses, and sizes are available to suit almost any construction joint. The advantage of PVC water stops is that they can be installed in virtually any conditions, including rainy and wet conditions. They also tend to last for a long time. The challenge comes in the actual install process. It takes time to correctly position the PVC to embed it in the joint, and during the concrete pour, it can easily become damaged.
2- Bentonite
Falling under the category of a hydrophilic water stop system, bentonite is a swellable clay compound that expands up to 16-times when it contacts water. This helps it form a compression seal in concrete joints and fill small areas like cracks and voids in the concrete. However, as a hydrophilic water stop, this characteristic also means it’s extremely important to keep the bentonite dry and pour concrete immediately after it’s applied. If bentonite is prematurely exposed to moisture,
it can damage joints, and weaken the concrete around the joint. There’s also a limited number of times the bentonite water stop can expand and contract. Eventually, they wear out and have to be replaced. This makes them better suited for applications that aren’t often subjected to water and moisture, rather than extreme weather conditions.
3- Urethane
Another hydrophilic compound, urethane also swells to form a compression seal in concrete joints when exposed to water. It grows to about 350-percent its original volume. Urethane water stops can also be applied in strips or using a caulking gun, which makes them quicker to install. They also need to be kept dry prior to application but need an additional 24 hours to cure before the concrete is poured. Throughout the curing process, the urethane needs to remain dry. And, like bentonite, urethane water stops will eventually wear out after being exposed to water many times.
4- Metallic
Typically made from copper, bronze, lead or steel, metallic water stops are embedded similarly to PVC water stops, however, because they are stronger, they’re used in specialized applications like dams or heavy construction projects and also in projects where materials will be exposed to extreme temperatures or chemicals.
