"Neither snow, nor rain, nor heat, nor gloom of night, stays these couriers from the swift completion of their appointed rounds." These words, thought to be the motto of the U.S. Postal Service (USPS), are chiseled in granite over the entrance to the New York City Post Office. While the USPS has no official motto, its mission states that it shall provide prompt, reliable and efficient postal services to patrons in all communities.
Achieving this mission is an ever-evolving challenge, as the USPS delivers almost half of the world’s mail to more than 150 million addresses each year. To ensure that the USPS continues to deliver on its universal service commitment, it is critical that its vast network of mail-processing and distribution centers throughout the nation operate efficiently and reliably.
The truck docks at the Capitol Heights facility are in constant use and undergo a high degree of wear and tear. When it was time to rebuild the severely deteriorated pavement in front of the docks, it was imperative to get the new concrete pads completed and operational as quickly as possible.
To ensure full use of the concrete ramps, the concrete needed to achieve a specified strength of 5,000 psi. The project involved a complete full-depth removal of the old concrete and replacement with a new 10-inch-thick, 3,100-square-foot concrete pavement. The work was scheduled across five to six docks at a time, so truck fleets could continue to deliver mail during the construction process.
To meet the speed-of-construction requirements and need for rapid strength gain, Aggregate Industries supplied more than 1,500 cubic yards of Chronolia®, an advanced quick-setting concrete that allowed for easier placement and delivered a 5,000-psi compressive strength in only 24 hours. Workability of the product ranges from 90 to 120 minutes from batching with the benefit of high early strength, enabling improved turnaround time and productivity.
“The performance of the Chronolia® was outstanding,” said Juan Calderon, president of Chilar Construction. “It allowed us to accelerate our work schedules, improve productivity and meet expedited job completion schedules requested by our customer. Like clockwork, we were removing traffic cones from the new concrete pavement every 24 hours to allow the trucks to back up into the docks.”
Completion of all the concrete loading-dock ramps throughout the NDC facility took only 24 working days—one month ahead of schedule.