The Jacksonville Utilities Authority contacted Alpha Foundations regarding a high-traffic bridge that was experiencing settlement. An 8 to 12 inch void had developed due to erosion and poor compaction of soils. Sleeper slabs were initially installed at the end of the approach slabs to aid in preventing settlement. The sleeper slabs added additional weight to the already compromised soils, which caused accelerated settlement of the slabs and consolidation of the soils.
The void under the bridge had caused the adjoining sidewalk and parts of the roadway to begin to settle. This, in turn, caused poor driving and walking conditions as well as safety concerns for pedestrians.
Alpha Foundations installed 1,300 pounds of PolyLEVEL™ 400 over the course of two days to completely fill the void and lift the road and walkways back to their normal elevation. The ease of access to the jobsite allowed us to keep one lane of traffic open during the installation. PolyLEVEL™ is the ideal application for void fill on roadways because it expands within 15 seconds and is 90% cured within 15 minutes which means minimal disruption for the client.
PolyLEVEL™ is a two-part urethane that expands into a rigid foam used to fill voids, stabilize slabs and lift concrete. Once injected through small 5/8-inch drilled “ports” in the slab, a chemical reaction converts the liquid urethane components to a strong, rapidly-setting foam material. In its foam state, PolyLEVEL™ is relatively light, weighing two to six pounds per cubic-foot (pcf). Other void-filling or lifting materials can weigh upwards of 120 pcf, adding significant weight to supporting soils or base materials and potentially contributing to further settlement issues, much like the sleeper slabs initially installed. With a compressive strength of 100 pounds per square-inch (psi), PolyLEVEL™ can provide the necessary resistance to support even heavy loads.