Backfill Between MSE Walls
Project: Exposition Light Rail
Owner: City of Los Angeles
Installed: 38,000 Cubic Yards
Approximately 38,000 cubic yards of foam concrete was placed between MSE walls. Densities ranged from 24 to 27 pcf with minimum strengths of 40 psi. This material requires no compaction, is re-excavatable and will not cause future settlement.
The initial plan called for a 40 PCF foam concrete material. Once the design/build team was shown the benefits of using an even lighter material without sacrificing strength, the engineers on the project recalculated the amount of materials and excavation needed on the project. The savings in money and time turned out to be substantial for both the owner and the design/build contractor.
Specialized equipment, included high speed colloidal mixers and progressive cavity pumps, was utilized to insure a high quality material. A lull was successfully used to control placement of the material. Daily production rates exceeded 1,000 cubic yards per 8 hour shift. This high production equipment is capable of placing 300+ cubic yards per hour.