Contractors are constantly battling the elements to get their work done on their clients' schedules, but sometimes conditions are such that perhaps the job shouldn't be done. Or, even if it is done, the result will be a less-than-optimum job.
Still, sometimes that job must go on. It's the contractor's responsibility to make sure the customer understands the situation and the possible ramifications of working in less-than-ideal conditions. It's also the contractor's job to make sure the work and finished product is the best product possible given the circumstances. Sometimes that means bringing in a consultant to offer guidance, sometimes it means altering your typical paving operation, sometimes it means crossing your fingers - and sometimes it means doing all that and more.
Such was the case when Spokane Rock Products had contracted to overlay a 50,000-sq.-ft. parking lot at NorthTown Mall in Spokane, WA. The parking lot was being used as the staging area for materials during construction of an addition to the mall, and it experienced a lot of construction traffic throughout the construction process. The mall addition was scheduled to open in mid-September; work on the parking lot overlay couldn't begin until late October; and the hot mix plant (owned by the contractor) was scheduled for shutdown on Thanksgiving Day.
So the first challenge was scheduling pavement repair and preparation, followed by actual paving, in a constricted time frame that the contractor knew was going to be upset throughout by inclement weather.
The second challenge, and the biggest one, was how to get the paving done so the overlay was a quality and long-lasting job when who knows what the temperatures were going to be in Spokane in November. Average October temperatures range from 36°F to 59°F while average November temperatures range from 29°F to 41°F (rainfall averages just over an inch in October and just over 2 inches in November).
So the mall hired CHEC Management Systems, and through communication with Robert Vander Linden, operations manager for NorthTown Mall, the contractor decided on a plan.
"The main concern any time you're paving in cool weather is the amount of time from when you place the hot mix to when it gets too cool and you can't get anymore compaction," says James Curtis, president, CHEC Management Systems.
"So we worked with them, and we discussed that if they were going to pave in below 50°F conditions they're going to have to tighten up the whole process. The paver is going to have to slow down, and the rollers are going to have to be closer to the paver, and we're going to have to do whatever we can to keep the heat in the mat for as long as possible. And they fully understood the situation and worked with us to come up with ideas to provide the customer with the best product possible."
Cracksealing and patching
Curtis says work to prepare the 50,000-sq.-ft. area for an overlay was similar to any other job. The contractor handled more than 10 remove-and-replace repairs ranging from smaller patches to patches as large as 19 ft. x 19 ft. and 18 ft. x 28 ft. Curtis says shrinkage cracks are common in the northern Washington climate, and this job had its share at 10 feet apart and in 10 ft. x 10 ft. squares.
Spokane Rock Products started the repairs the last week of October, but because of rain the repairs weren't completed until early November. Eventually the pavement was ready: Cracks had been sealed, patches were done, and manhole risers had been installed throughout the area. It was time to pave - but Spokane Rock Products had only two weeks before its plant would shut down, and the last day it could get mix was the Wednesday before Thanksgiving.
Curtis says Spokane Rock Products was able to succeed on this job because it understood the challenges of the job, it was willing to adapt its paving practices to a new situation, and the crew was able to make the changes necessary and stick to them throughout the job.