Cell-Crete Corporation has been contracted by Brosamer & Wall, Inc. to supply lightweight cellular concrete (LCC) backfill for the purpose of increasing roadway grade and widening this section of the highway. Cellular concrete allows for the design grade increase without excessive loading on sensitive delta soil, and saves costs on retaining the wall design.

This project was initiated in July of 2019. Starting near Grayson Creek, Cell-Crete is installing 63,000 CY (cubic units) of 27 PCF (pounds per cubic foot) of LCC over the course of two years. The first phase of this project increased the grade between and on the outside of the existing highway, developing the northbound I-680 to the westbound SR 4 ramp. Phase II traffic will reroute onto the new material while cellular concrete fills and increases elevation of the old highway lanes. This phase is focused on creating a two-lane connector ramp from the eastbound SR 4 to the southbound I-680.