Are you interested in learning more about curtain grouting? If so, don’t hit that back button because this short article covers the basics of curtain grouting. We’re going to cover what curtain grouting is, why you might need to use a grout curtain, the curtain grouting procedure, and more.
What Is Curtain Grouting?
Curtain grouting is a waterproofing technique used to stop multiple leaks in underground structures such as tunnels, parking garages, basements, manholes, and more. The rigid, hydrophobic grout is able to maintain its size, strength, and impermeable nature under most soil conditions.
Curtain grouting doesn’t require excavation, and it’s usually used in civil and industrial situations where excavation would be prohibitively expensive. Curtain grouting is able to stop water leaks that are flowing up to 15,000 gallons/minute.
Curtain Grouting Is Not The Same As Soil Stabilization
Although both curtain grouting and soil stabilization involve injecting something into the soil, curtain grouting is used for waterproofing. While it’s true that curtain grouting does strengthen the soil around a structure in that it compacts and binds the soil particles together, it’s primarily used for waterproofing. Soil stabilization is used to make the soil stronger.
Why You Might Need To Use A Grout Curtain
You might need to use a grout curtain if:
- You’ve tried other waterproofing methods without results.
- Excavation isn’t possible for some reason – This might be because of a high water table, the job site doesn’t allow for excavation or some other reason. Because excavation isn’t necessary for curtain grouting, this saves both time and money.
- When you need to fill voids underground – The voids might be caused by various things and curtain grouting will fill these voids in the soil outside the structure’s walls. Also, any water already there will be expelled, which will either reduce or eliminate hydrostatic pressure pushing against the structure.
- When you have active water leaks in underground structures like tunnels – The hydrophobic polyurethane grout is perfect for sealing active water leaks because it won’t dilute when it comes into contact with water. It repels water and pushes it back into the substrate.
- When you need to prevent erosion in structures built near bodies of water – For example, seawalls and underground tunnels.
- When you’re faced with water leaks flowing at 1000s of gallons/minute.
- When you need to stop multiple leaks at the same time.
- When you need to prevent multiple leaks through a brick or block wall – Crack injection in a block basement wall can be time-consuming and, ultimately, a never-ending process as new leaks pops up for every leak you fix. Curtain grouting allows you to seal multiple leaks simultaneously by creating an impenetrable waterproof barrier that stops water from coming into contact with the structure.
Keep in mind that when the concrete is damaged – cracks, etc. – a grout curtain behind the wall will keep water out. However, it doesn’t address the wall’s structural issues. Those will need to be fixed using another repair method.
Curtain Grouting Procedure To Stop Water Leaking Through A Wall
The curtain grouting procedure to stop water from leaking through a wall is as follows:
- Small holes – about 2-3 inches apart – are drilled in the wall where the water is leaking through. The holes go all the way through the wall and into the soil behind the wall.
- An injector is placed into each hole.
- An injection gun – attached to a pump – is inserted into each of the injectors placed into the holes.
- The chemical grout is injected through the holes and into the soil behind the wall, starting with one of the lowest holes.
- The grout expands and creates a solid mass that water cannot penetrate. No water will leak through the wall after curtain grouting because the wall is now isolated from groundwater.
Case Study: The Aswan High Dam in Egypt