Masonry Magazine October 1981 Page. 12
This architectural rendering depicting a highway underpass treatment in Arizona features unit masonry retaining walls and flower boxes in the state's proposed highway beautification program.
MASONRY SOUND BARRIERS
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"Highway construction funds are as tight in Arizona as elsewhere, probably even tighter," Rosensteel observed. "Due to delays brought on by land acquisition procedures and legal mandates to conduct archeological digs along several proposed routes, the costs for right-of-way land have skyrocketed. As a result, little priority has been given for the comparatively small amount of monies required to provide the noise control and beautification features offered by baffle walls.
"The key will be public pressure for them," he concluded. "And when it comes, we have the plans, the materials and the manpower ready to go."
California Builds Concrete Block Walls
In California, where more than 75 miles of sound barriers have been constructed, 80 to 90 percent are built of concrete masonry, that is, concrete block rather than precast or poured-in-place concrete. A spokesman for the California Department of Transportation (DOT) attributes this great usage of concrete block, in part, to the unusually strong participation of California citizens in making decisions about their highway barriers.
This participation was augmented in 1974 when the state's Department of Transportation established the "Community Noise Program," which was undertaken to help people "severely impacted by noise" via an intensive retrofit of existing freeways. The California DOT official said that when given a choice among various materials for their barriers, community members chose concrete masonry because of its durability, low maintenance and attractive appearance.
They also preferred masonry sound baffles because they easily accommodate adjoining walls if extension of the barrier becomes necessary.
According to a report recently developed by the Office of Structures Design of the California DOT, the pricing of concrete block, compared to that of poured and precast concrete, was also very favorable. While a concrete block sound barrier averaged $5.70 per square foot installed, a precast concrete barrier (4 inches thick) was $9.50 per square foot, and a poured-in-place concrete barrier was $10 to $11 per square foot, depending on thickness.
The natural beauty of masonry baffle walls can be enhanced by the creative use of color, as shown in two recently constructed sound barriers in Philadelphia. Mosaic configurations of red, green, blue and yellow concrete block-pre-colored with mineral additives were used to create spectacular murals lining both sides of the city's busy 1-95.
The murals depict people, trees, large rising suns, the moon, colonial homes, boats on the Delaware, geodesic solar buildings and mass transit. The concrete block mosaic, conceived and created by three Phildelphia-area citizens, demonstrates what the public can achieve in concerted efforts to improve their environment.
Although community response to the aesthetics of a sound barrier is an important consideration, local highway authorities must still make cost-effectiveness a top priority.
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