Soft aggregate, sound solution

This summer a four-mile stretch of the Dulles Connector Road became the first phase of a larger project in northern Virginia to include ground-mounted sound walls containing SoftSound, a sound FF-HwySnd1-300
absorptive technology. Approximately 277,000 square feet of precast concrete sound wall will be placed on the west side of the roadway between Chain Bridge Road/Route 123 and Interstate 66. The sound walls will mitigate noise from Dulles Connector Road traffic and the new Dulles Metrorail Silver Line extension, which has been constructed at-grade in the median and on elevated rail flyovers along the roadway.

Agencies in northern Virginia have adopted some of the latest in highway traffic management and sound abatement measures. Sound walls containing SoftSound—a proprietary material that is molded and compressed from highly-specialized mineralized wood-chip aggregate and cement—are being installed alongside Dulles Connector Road and the Metrorail Silver Line extension to create a quieter environment for area residents.

Midland, Va.-based Smith-Midland Corp. delivered up to 4,000 square feet of precast panels to the jobsite daily. The panels are made from precast concrete and include a sound-absorptive finish on the roadway side. SoftSound is a proprietary material that is molded and compressed to meet desired technical and aesthetic requirements. It combines a highly-specialized mineralized wood-chip aggregate using cement as a binder in a specific and exacting manufacturing process. Once installed, SoftSound surpasses other products for sound absorption, durability, strength, and moldability, Smith-Midland engineers contend.

The new structure will replace a deteriorating wooden wall that weaves through several residential neighborhoods. “The DOT wanted a new wall that was not only permanent, but that would also create a quieter environment for area residents,” says Matthew Smith, vice president of Sales and Marketing for Smith-Midland. Similar care has been taken during installation, with contractor Lane Construction of Cheshire, Conn., erecting the structure in a manner that minimizes noise intrusion on the adjoining neighborhoods.

Produced under stringent quality assurance standards, SoftSound has been extensively tested to meet or exceed all state DOT FF-HwySnd3-200
requirements. “By adopting a strict approach to quality, we can avoid some of the performance issues associated with other sound absorptive products,” says Moffette Tharpe, managing director for Easi-Set Worldwide, SoftSound’s developer and licensor, “and ensure more successful project outcomes for the long term.”

Managed by the Commonwealth of Virginia Department of Transportation, the Dulles Connector Road (Route 267) serves a 16-mile corridor between I-66 in Falls Church, Va., and Dulles International Airport in Chantilly, Va.