By Greg Argos

PHILADELPHIA (CBS) — With all the construction happening in Philadelphia, it’s obvious there is a building boom. At 500 Walnut Street, which will open as luxury condominiums, crews are hard at work laying more than 450,000 cubic yards of concrete.

“There is a pump truck on the ground that pumps the concrete up through the tube and up through this placement boom and then it comes down and out to the place you need it to be,” explained tower crane foreman Anthony DiMurcurio.

On the 500 Walnut Street project alone, enough concrete will be poured to fill more than five Olympic sized swimming pools and it all has to come from somewhere.

With 44 trucks and three manufacturing plants, Castor Materials provides the concrete for many of the jungle’s newer buildings.

Vice President Bill Hagstotz says the concrete is made to specific measurements based on the type of building, loaded into trucks where it’s then poured, molded and smoothed into whatever will change the Philly skyline. “We get the sand. We get the cement. We get the stone. We bring it together and add some mixture,” he explained.

“Obviously with the building boom, it’s just been phew!”