When an underground pipe or structure is abandoned, the two basic options that are considered are (1) pipe abandonment, or (2) removal. The removal option is often not feasible or cost-effective.
A structure or pipeline that is abandoned in place without filling may deteriorate and lead to ground subsidence which in turn creates the potential for water erosion, impacting future land use and posing safety issues. It is extremely important these lines be filled if they are located beneath a road, railway or other areas sensitive to subsidence.
Deciding what to fill an abandoned pipe or structure with involves a variety of factors such as diameter, length and condition of the structure. Because it is highly flowable and can be pumped over long distances, Foam concrete (aka cellular concrete) is often the material of choice. Another commonly considered material is a sand/cement slurry, however, foam concrete has proven to have significant advantages:
- More flowable and will fill the pipe or structure more completely.
- Can be placed with lower pumping pressures which reduces risk of damage to pipe or structure.
- Requires fewer access points due to the fact that it can be pumped over 5,000 feet while sand/cement slurries are limited to under 500 feet: fewer access points mean lower costs and less disruption.
Every abandonment project involves its own unique set of challenges. Access is to the structure is often limited, requiring the fill material to be pumped long distances. MixOnSite offers a complete solution with its foam concrete products and complete installation services including mix design support, state of the art equipment and experienced crews.