The Job
This Pittsburgh pipe abandonment project is located within the city of Pittsburgh, Pennsylvania. It is part of the Rising Mains No 3 & 4 replacement project. Plans call for filling with grout roughly 1575LF of 48″ water main.
The Challenge
The abandonment was specified for traditional controlled low strength material (flowable fill). However the contractor had doubts about being able to successfully perform the pipe abandonments with flowable fill. These concerns were based on access limitations, ready mix delivery limitations and the roughly 20′ of elevation change over the length of the pipe.
The Solution
The contractor reached out to CJGeo about using low density controlled low strength material (LD-CLSM). CJGeo evaluated the pipeline as-builts and recommended a CJGeo 25lb/cuft CJFill-Ultra Lightweight cellular concrete mix design. 25lb/cuft CJFill-Ultra Lightweight’s average 80psi compressive strength at 28 days (ASTM C495) is ideal for abandoning the pipes. The low density maximizes yield (finished volume per ton of cement), and provides adequate bearing capacity in most situations.
Using onsite dry batching, CJGeo generated and placed 730CY of grout to successfully fill the pipe, which was access near the middle to create two segments. The work took two days onsite to complete. Onsite batching directly from bulk cement was advantageous on this project for the following reasons:
- economical – it costs significantly less than ready mix flowable fill
- speed – CJGeo made more than 100CY of CJFill-UL per hour
- safety – peak placement pressures were less than ten psi
- logistics – it only took five loads of cement, whereas flowable fill would have taken 92 loads
Speak With An Expert
Facing a similar challenge to this Pittsburgh pipe abandonment project that CJGeo completed with CJFill-Ultra Lightweight cellular grout? 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.
