When replacing lighting that’s embedded in a runway, work must adhere to a strict schedule so it does not disrupt flight schedules. The construction is typically performed at night.
Centerline lighting at Reagan National Airport was replaced in 2011 and 2012. The scope of work included coring and cutting out each light can, with holes measuring approximately 2 ft. in diameter by 3 ft. deep. Lights are spaced approximately 50 ft. apart and trenches for new conduit between the lights measured approximately 6 in. to 8 in. wide by 2 ft. deep.
Each night, crews were tasked with completing a predetermined number of linear feet, with work that included removal of the existing lighting and placing new conduit and light cans. On average, 200 ft. to 300 ft. of production was accomplished per night. Once the new conduit and light cans were installed, Rapid Set® Cement was used to produce a pre-approved concrete mix design to fill trenches and cores. It exceeded the contract’s required strength of 3500 psi in four hours.
Rapid Set Cement was ideal for the project because it can achieve a strength of 3500 psi in two hours—half the specified requirement. This resulted in a longer production window for the contractor each night, a valuable benefit because contract penalties for construction delays on runways can be extremely punitive.
The Rapid Set concrete was produced by a volumetric mixer finished with hand trowels and wet cured. Rapid Set Cement offered reliable set times and strength gain, characteristics that were sampled and tested each night before the runway was approved for aircraft landing.