Silver Award – I-376, Airport to Business 376, Alleghany, PA
Contractor: Golden Triangle Construction*
Owner/ Engineer: PennDOT, District 11
I-376 Airport Expressway is a limited access freeway that serves as the main access for high speed traffic traveling to Pittsburgh International Airport from the Metropolitan Pittsburgh Area. The average daily traffic on this highway is 50,000, but ADT is expected to climb to 70,000 vehicles.
Golden Triangle Construction won the alternate bid for the project, which included full-depth concrete replacement, minor structure improvements of four major bridges, and updates to the guide rail and median, along with some additional construction. The entire project included 20 lane miles of paving over a span of
4.7 miles. The project also included two major interchanges that serve airport cargo companies and other airport vendors, as well as other businesses in the area.
After being awarded the contract, Golden Triangle proposed three innovative cost-saving ideas:
- Using 12 in.-thick cement soil stabilization in lieu of traditional undercutting methods to stabilize the subgrade;
- Recycling existing concrete pavement and reusing it for the aggregate subbase vs. purchasing virgin aggregate; and
- Designing a new maintenance and protection-of-traffic scheme to allow for full 24 ft.-wide paving in lieu of single lane 12 ft. lane paving.
These recommendations allowed for expedited construction, safer access for construction and passenger vehicle traffic and a smoother pavement. In addition to Golden Triangle’s proactive strategies providing a better finished product, they also saved the PennDOT $1.4 million of the approximately $13.4 million allocated for paving.
Another innovation on the project was the pilot of Performance Engineer Mixtures for PennDOT. Applying the use of the formation factor test, box test, Super Air Meter and water/cement ratio calculation using the microwave test, provided feedback to PennDOT and the contractor, and may lead to the use of more PEM mixtures on future projects.
* ACPA member.