How long does grouting a sewer main last?

[CivilEngineer401]

I am trying to figure out what is a reasonable life expectancy for grouting sewer main joints. The webinars that I see online state that grout (such as Avanti AV-100 Acrylamide Grout) will last forever. It is approved by the US Department of Energy to encapsulate radioactive waste and is rated to last 362 years (I loved the accuracy. Why not 363 years?)

On the other hand, I have heard from some municipalities that they only use grout sparingly or not at all since it only lasts 10 years in the field. I believe the problem is that the ground shifts and you have a leak again. What is everyone’s experience? Is it worth the money to grout sewer main joints and lateral connections?

 

[bimr]

It is definitely worth the money to grout sewer main joints and lateral connections. The lifetime of the repairs is difficult to estimate because you have different field conditions and as well as the ability of the people making the repairs. Work with the suppliers to obtain a guarantee on their work.

 

[swazimatt]

what material are your pipes?
is this grouting where the pipes enter the manholes?

 

[CivilEngineer401]

The pipes in question are made of terra cotta, and the grouting I'm referring to is not limited to where the pipes enter the manholes. Instead, it's the type of grouting that's injected into the joints of a pipe anywhere along the sewer main. This process is done from inside the pipe by a machine, aiming to seal the joints and prevent leaks.

 

[swazimatt]

I was not aware places still used terra cotta ww pipes, would have thought everyone had switched over to PVC. Is this new pipes or maintenance of existing pipes?
I believe there have been major advances in WW pipe lining with minimal loss of CS area

 

[CivilEngineer401]

It is maintenance of existing pipes that has groundwater coming in the joints and cracks in the pipe.

 

[bimr]

swazimatt

Most of the time, it is repair of existing clay pipes. Clay pipe is typically 3-4 feet long, so it has many joints which are potential leakage paths.

Modern vitrified clay sewer pipes are air-dried for 24 hours and then fired in a kiln for 50 hours, creating a ceramic-like end product. This material also referred to as terra cotta, is stronger and fits together more tightly than older clay plumbing. It’s still routinely used in public sewer systems today. Modern installations include encasing the clay pipes in concrete to protect against root intrusion and damage from ground shifting.

There are some still-functioning clay pipe systems in the United States that were installed over 100 years ago. There are even some ancient plumbing systems that continue to operate, like the one in Ephesus. Generally, whenever these pipes fail, they are replaced with other materials.

NCPI

 

[swazimatt]

I was enquiring if it was still used in new installations, i often come accross existing TC pipes. I am aware of terra cotta half-sections still being manufactured for use in manhole benching, but even this is slowly falling away.

the pipe lining that seems to be popping up a fair amount is this Link