Urban noise is unquestionably a real and significant problem in society today. From the residents who must live with it to those are faced with doing something about it, urban noise has become the subject of concerns and headlines in many urban areas.
Among those working the issue are federal, state and local agencies; other public officials; academia; and, of course, industry organizations, including the American Concrete Pavement Association (ACPA).
No discussion about tire/pavement noise would be complete without noting that the concrete pavement industry presently offers a number of solutions to address tire/pavement noise-both in new construction and existing pavements.
“Smooth, quiet pavements can be and are being built using quality design and construction practices,” said Gerald F. Voigt, P.E., ACPA President and CEO. “In addition, diamond grinding offers a practical solution for imparting a smooth, quiet pavement surface.”
Given the urgency and imperative to meet the demand for quieter pavements, however, ACPA has embarked on a major research initiative focused on surface characteristics—they primary attribute that determines a smooth, quiet pavement.
“There are two hallmarks of this research,” Voigt said, adding, “We will not trade off safety or long-term performance, and we will strive to avoid significantly increasing initial costs or life-cycle costs.”
A major milestone was achieved in September when the Federal Highway Administration (FHWA), encouraged by ACPA, altered its long-standing position on use of transverse-tined texture.
The FHWA’s original position was adopted in 1978 and stood until the change. ACPA pushed for a full spectrum of concrete pavement textures to be allowed. The new policy allows states to use a variety of textures, including the types used in Europe, as long as the states demonstrate that they meet the state’s safety requirements.
The path has been cleared at the FHWA policy level, but there is still much work to be done through research, outreach and technology transfer.
Intense situation
The industry is drawing from experience in European countries (including Belgium, England, France and Germany), with the goal of optimizing a texture for the U.S. We have studied noise-testing results from European countries and available U.S. research.
Considerable amounts of research data are available, but comparisons between European noise data and U.S. noise data are difficult because of a lack of a standard for measurement. Each European country uses a different device. In the U.S., there are only a few consultants and two states that have noise-testing equipment.
To address this barrier, ACPA research is advocating a single type of equipment—sound intensity, or SI—which experts have suggested will become the standard in the U.S. ACPA’s data will be comparable to the results from recent studies of European textures from a testing program called the Noise Intensity Testing Europe, or NITE program.
There are significant unanswered questions about even the quietest European concrete textures, exposed aggregate and porous concrete, that prevent immediate application in the U.S.
The latest information from Germany shows that there have been durability problems with porous materials. The durability of porous concrete is unproven in freezing environments and for highway traffic loads and volumes.
ACPA is either leading the charge or participating as a major stakeholder in a number of tire-pavement noise research and testing initiatives, according to Larry Scofield, P.E., ACPA’s Director of Environmental Engineering. Included within the range of research and testing are field experiments and laboratory testing.
A number of other noteworthy initiatives also will prove useful to the ongoing research and evaluation of surface characteristics and noise, Scofield said, noting the efforts of the Federal Highway Administration, the National Cooperative Highway Research Program, and others.
“We’re pleased to be working closely with many of the key stakeholders who are committed to understanding and solving this issue,” he said. “Our industry, with support from our members and affiliates, is both serious and focused on sharing current solutions while also exploring new technologies that address tire/pavement noise without trading off durability or increasing costs.”
In addition to current research initiatives, ACPA has made preliminary arrangements to work with representatives of 10 countries from Europe, Asia, South America and Australia. ACPA also will be participating in an international scanning tour and also will participate in the International Conference on Concrete Pavement in Brussels next year.
ACPA is confident that the answers to many of the questions and concerns about tire/pavement noise already exist for agencies and contractors. Still, the association is working to enhance the surface characteristics of concrete pavements.
“ACPA, along with other stakeholders, is addressing the issue of tire/pavement noise,” Voigt said. “We are well on our way to finding even more solutions to this issue, but it’s important not to overlook the technologies and practices that exist today. We encourage any state or local agency with questions to call ACPA or its local ACPA chapter or state paving association. Answers to questions about tire/pavement noise are certainly within reach.”
For questions or additional information about surface characteristics and tire/pavement noise, contact Larry Scofield at 480/775-0908.
