Downtown Courts Complex

Location:

Tucson, Arizona

Scope of Work:

  • Special Inspection
  • Materials Testing
  • Laboratory Testing
  • Written Report

Ninyo & Moore provided construction materials testing and inspection services for the Pima County Downtown Courts Complex (DCC). Pima County elected to utilize the Construction Manager at Risk (CMAR) delivery process for this project. The DCC includes construction of a 257,000 square foot, seven-story above grade structure with a basement level and partial mezzanine/penthouse level. A stand-alone Central Plant will also be constructed as part of Phase I. The DCC will be a steel-framed structure bearing on a combination of drilled piers and a mat foundation. The Central Plant will be a masonry-framed structure, also bearing on a mat foundation. Site work will include miscellaneous on-site and offsite utilities, asphalt and concrete paving, and associated appurtenances.

Project Challenge: The DCC was designed with a 6-foot mat foundation on a 1-acre foot print, placed 25 feet below grade in two separate placement events. The placements were accommodated by four concrete pumps and a tele-belt conveyor system at various locations around the site, which placed 300 to 500 cubic yards per hour. The specification for air content and slump was to be closely followed, and sampling was required for every 50 cubic yards. Due to the rapid placement, there would not be enough time to test the trucks at the pumps before they would be completely unloaded.

Innovative Solution: Ninyo & Moore dispatched 15 technicians for each of the mat foundation concrete placements. The technicians were divided into “street teams” and “pump teams”. Due to the speed of placement, as trucks queued in front of the two site portals, Ninyo & Moore street teams checked the slump and air of every 5th truck, and rejected out-of-specification trucks before entering the project site. The street teams also tagged the in-specification trucks with a neon sample tag on the driver door. As the trucks pulled up to the pump locations, the pump teams sampled each tagged truck for concrete cylinders. The cylinders were site cured in troughs located with each pump team.

Services: Ninyo & Moore's services included testing and inspection services associated with fill and backfill of soils and aggregate materials; field and laboratory sampling and testing of concrete, masonry, grout, and mortar materials; visual weld and bolt torque inspections; and inspection of spray-applied fireproofing materials.