The document discusses the Next Generation Concrete Surface (NGCS), which provides a smoother, quieter ride compared to traditional concrete surfaces. NGCS has a predominantly negative texture created through diamond grinding that reduces tire/pavement noise by up to 75%. It has been installed successfully in several locations internationally, including Minnesota, Australia, South Korea, and Houston, Texas, where it has significantly reduced road noise levels. NGCS can be used for both new construction and rehabilitation of existing surfaces.
2. Quieter Travel on the World’s Highways
In the past, concrete
pavements were
associated with increased
tire/pavement noise. In
recent years, however,
the Next Generation
Concrete Surface (NGCS)
has provided quieter
travel, increased friction
and improved ride.
3. Benefits of NGCS
Smoother Ride: The innovative texture provides for a
smoother, more uniform ride.
Increased Safety: Diamond grinding provides increased
macro-texture, creating a safer road in wet weather
conditions.
Decreased Noise: Tests have shown a decrease in
tire/pavement noise by 75%.
4. How Does NGCS Work?
NGCS is a diamond saw-cut surface that is absent of positive or upward
texture, resulting in a uniform land profile design with a predominantly
negative texture. This profile is responsible for the lower overall noise level.
5. How Does NGCS Work (continued)?
Despite the flatter, smoother riding
surface, the NGCS still possesses
and maintains reliable microtexture
(friction) when constructed with
quality aggregates.
The longitudinal grooves provide
substantial macrotexure and
increase the resistance to
hydroplaning by providing escape
channels allowing water to move
out of the tire contact patch area.
6. How is NGCS Installed?
The NGCS is installed using conventional
diamond grinding equipment:
Concrete is flush ground using 1/8
inch wide blades with 0.035 inch
spacers.
1/8 inch wide longitudinal grooves
are saw-cut to a depth of 1/8 - 3/16
at 1/2 - 5/8 inch centers.
The grinding process can be
accomplished in single lane
operations and short lane closures
when necessary.
7. Versatility of NGCS
NGCS can be used for
both new construction
and rehabilitation of
existing surfaces. It can be
quickly and efficiently
constructed without
impacting other roadway
features such as
guardrails, barriers or
curbs.
8. NGCS History
The NGCS surface was developed at Purdue University in 2007, with the
support of the International Grooving & Grinding Association, the American
Concrete Pavement Association and the Portland Cement Association.
Tire Pavement Test Apparatus,
Herrick Lab, Purdue University
9. Testing NGCS
Three years of field testing and
evaluation were conducted by
the Minnesota Department of
Transportation (MnDOT) at
their MnROAD pavement
research facility. NGCS was
tested in both low and high
volume traffic.
Tests showed NGCS sound
levels at the sub-100 decibel
level, the quietest non-porous
concrete surface ever
measured.
10. Testing NGCS
Two of the largest quiet pavement research programs in the country both
evaluated NGCS:
Virginia Tech Transportation Institute reported:
“...a measurable and noticeable decrease of more than 5 dB(A)
for the NGCS.“
"NGCS is reliable in terms of noise variability between
different locations.“
U.C. Davis reported NGCS was: quieter than conventional diamond
grinding (CDG) and also offered improved smoothness (as
measured by the International Roughness Index, or IRI).
11. NGCS Track Record: Duluth, Minn. (2010)
Minnesota constructed the first large NGCS project on I-35 in downtown
Duluth. According to press coverage:
Noise was reduced by 6 decibels on the northernmost section of the I-35
megaproject. (6 decibels translates to an 80% reduction in the overall
sound of vehicle tire noise. )
One resort owner reported:
“The sound of I-35 traffic had been the number one complaint of
hotel guests…[After NGCS was installed] we haven’t fielded one
complaint.”
-- Justin Steinbach, general manager of the Edgewater Resort and Waterpark
13. NGCS Track Record: NSW, Australia (2014-ongoing)
By 2014, New South Wales (NSW) was experiencing increasing urbanization
along road corridors resulting in environmental noise legislation. After
constructing several test sections, Australia's Roads and Maritime Services
(RMS) slightly modified the NGCS, calling the adaptation Low Noise Diamond
Grinding (LNDG), finding it suitable to meet their needs.
This surface now serves as a lower cost alternative to asphalt surfacing
for noise reduction on their Continuously Reinforced Concrete Pavement.
The RMS constructed test pavements in which the savings gained from
using NGCS on jointed plain concrete pavement in comparison to their
current overlay practices is estimated to be $720,000 per kilometer of
dual carriageway.
15. NGCS Track Record: South Korea (2014-ongoing)
Korea has a network of state-of-the-art roadways, many of which involve
miles of tunnels.
In 2014, a pilot NGCS project was completed by the Korea Expressway
Corporation's Research Institute.
Preliminary tests of the NGCS during the pilot project demonstrated noise
reduction of 1.5-7.5 dB(A).
Pavement smoothness measurements indicate an IRI of 0.65 m/km.
Improvement of frictional forces, tested according to the ASTM E 501 sliding
friction test, was an average of 52.7 on the sliding resistance index.
16. NGCS Track Record: South Korea (2014-ongoing)
Today, NGCS is used throughout South Korea on all new expressway
tunnels that are 2 kilometers (1.24 miles) or more in length.
Use of the surface is expanding beyond roads owned by the Korea
Expressway Corporation to national highways and local roads.
There are nearly 1.5 million square yards 200 lane miles of NGCS in
South Korea.
18. NGCS Track Record: Houston, Texas (2011-ongoing)
TxDOT - Houston District (the largest DOT district in the state) incorporated NGCS
into several major highways, including I-10, Harris County’s U.S. 290, and the 610
Loop.
Houston has constructed approximately 3 million square yards of NGCS as of
2018.
19. NGCS Track Record: Houston, Texas (2011-ongoing)
Watch the 2016 TxDOT Best Practices Video Summary Report discussing NGCS.
20. NGCS Track Record: Katy Freeway, Houston, TX (2017)
After reconstruction in 2009, the Katy Freeway became the widest freeway in the
world and suffered major noise issues that affected residential villages along a
4-5 mile section of the freeway.
Concerned residents worked with their local mayors and elected officials, who in
turn worked with TxDOT, to install NGCS.
TxDOT has received positive feedback from both the driving public and elected
officials since constructing the NGCS in these areas.
In the years since we undertook noise abatement on I-10, NGCS has
become much more common in Texas. The cost and ineffectiveness of
sound walls is likely driving the adoption of NGCS as a solution that
addresses noise at its source."
- David A. Wegner, five-time mayor of Hunters Creek Village
21. Contact the IGGA today to learn more.
The IGGA provides a suite of resources on the NGCS here.