The Job
This lightweight stem wall backfill work is part of the construction of a new academic building at a school in Lynchburg, Virginia.
The Challenge
There was up to an 8′ difference in elevation between the existing ground and the desired finish floor elevation. Various options for filling the CMU stem walls included soil, aggregates and EPS foam blocks. EPS foam blocks were chosen to reduce loads on the footings. Otherwise, which would have required deep foundations in the case of soil or aggregate backfilling.
Due to the extensive sub-slab plumbing, the design called for EPS blocks cut to fit the curved walls & uneven ground profile, and then backfilled with 18″ of stone dust, to allow for the plumbers to dig and install the plumbing.
The Solution
The goal was to speed construction and reduce costs. CJGeo worked with the general contractor, structural engineer and geotechnical engineer to design a self-consolidating backfill system as a geofoam alternative. The final design for the lightweight stem wall backfill was 25lb/cuft CJFill-Ultra Lightweight load reducing backfill.
Using the dry batch generation process, a single CJGeo crew made up to two hundred cubic yards per hour of CJFill-UL. Pouring in two foot lifts, the work took about four days onsite. Instead of having to install an 18″ thick sand layer, the plumbers hand dug through the CJFill-UL to install the plumbing. Plumbing trenches were backfilled with stone dust.
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Facing a similar challenge to this lightweight stem wall backfill project? Give us a shout or shoot us a text. Click the state marker for the location of your project for contact info for the appropriate rep.
