Route 20, one of the major routes through western Massachusetts, will be undergoing a variety of construction jobs this summer in order to upgrade approximately 7 mi. (11.3 km) of highway between Lee and Becket. To do so, some of the latest techniques in construction technology will be utilized.
Approximately 8,000 ft. (2,426.7 m) of road in Lee will receive what is called a “white- topping,” an experimental process where the existing blacktop will be covered with 4 in. (10.2 cm) of concrete pavement. According to Doug Cope of the Massachusetts Department of Transportation (MassHighway), white-topping is not a typical way of treating highways that have deteriorated.
Man-made fabrics known as geotextiles also will play a large role in the plan. Erosion caused by spring runoff at nearby Green Water Pond will be inhibited through a process of slope stabilization. Geotextiles will be placed under a cover of gravel on a slope next to the highway and a pre-cast culvert installed to help prevent erosion.
“That will help keep the ground in place,” said Todd Andrews, an estimator for Petricca Construction Company, of Pittsfield, MA, the primary contractor for the project. “It [the project] encompasses a little bit of everything,” he added.
According to the American Concrete Pavement Association, concrete has a one-and-a-half to two times greater service life than those done with asphalt. To create the white-topping, workers core the existing asphalt to determine its depth, type and condition and then prepare it by blasting it with either water or an abrasive. Concrete is then poured on top of the old asphalt, followed by the traditional processes of finishing, texturing, curing and sawing the joints. It costs between $1.50 and $2.50 per square foot, not including the surface preparation, to use white-topping.
As for the slope stabilization, a geotextile will be placed over the soil and under several inches of gravel to help prevent it from being swept away by erosion. Although the fabric, which comes in both woven and nonwoven forms, will keep water moving over the area, the soil will remain in place, thus eliminating the threat of erosion.
Nonwoven fabrics are made entirely of polypropylene fibers that have been mechanically interlocked, making it both permeable and durable at the same time. It cannot decompose because it is made of a petrochemical-based polymer that is chemically and biologically inert. It can, however, decay from exposure to ultraviolet light.
The fabric is placed on top of the soil and then gravel spread over that, so all three levels are kept separate. For every 500 sq. yds. (400 sq m) of geotextile, it takes about 110 tons (99 tons) of gravel to cover it with a 6-in. (15.24 cm) layer. Water then can drip through the gravel and geotextile into the soil without the threat of it eroding, because the fabric holds the soil down.
Other parts of Route 20 will receive far more traditional treatment. For example, its intersection with Route 8 will be realigned to make it safer. Currently, it is laid out like an interstate on-ramp, but after the work is done, it will be a traditional “T” intersection set at a 90-degree angle.
Work also includes resurfacing and widening 7 mi. (11.3 km) of highway between the intersections with Route 102 in Lee and Route 8 South in Becket. “We are widening the shoulder because it is beginning to unravel in Becket,” Andrews explained.
There also will be isolated work along the road, by making repairs on the subgrade of the highway and adding new gravel. “We’ll be doing a large array of activities, such as drainage and guardrails. It is more than just an overlay,” Andrews said. No work is needed on any of the bridges along the length of highway, he added.
Andrews said that construction just started this spring and that the bulk of it will be finished this year. The completion date, however, is Spring 2003.
But this past winter was a mild one, so work was started earlier than it normally would have. Subsequently, workers started clearing brush in February. Because it is located in the western part of MA, far from the coast, projects usually do not start very early in the spring. But with mild temperatures and little snowfall this year, not much stood in the way of progress.
Petricca was awarded the contract by submitting the low bid of $6,248,789. The state is dedicating more than $700 million a year over the next five years to road and bridge reconstruction, a figure that is independent of Boston’s Central Artery project, otherwise known as “The Big Dig.”
Work on the road crossings will be done by Badger excavators, according to Andrews, along with Kubota 350s, which are much like Caterpillar 235s. By the time the work is finished, 28,000 cu. yds. (21,407 cu m) of earth will have been moved, Andrews said.
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