Noiseless Pavements

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ByJestin John

B110286CE

NOISELESSPAVEMENTS

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WHAT IS NOISE POLLUTION ?Sound that is unwanted or disrupts ones quality oflife is called as noise.

Sound becomes undesirable when it disturbs the

normal activities such as working, sleeping, andduring conversations.

It is an underrated environmental problem because of

the fact that we cant see, smell, or taste it.

World Health Organization stated that Noise must berecognized as a major threat to human well- being

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Health EffectsThere are direct links between noise and health. Also,noise pollution adversely affects the lives of millions of

people.

Noise pollution can damage physiological and psychological health.

High blood pressure, stress related illness, sleep

disruption, hearing loss, and productivity loss are the problems related to noise pollution.

It can also cause memory loss, severe depression, and panic attacks.3


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The noise level alongside a freeway might be in

the range of 70 to 80 db.

Exterior noise levels reach 65 to 70 db, people

living inside the building have to close window tohold conversation.

Noise levels in home should not exceed 40-45 db,levels that are often exceeded by traffic noise withthe windows closed .

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Do not reduce noise atsource.

Increasing the distance between the source and the

receiver.Inserting an obstruction (such as a noise barrier wall).

How to control noise?

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67 dB(A)

50 ft

A reduction of 3 dB(A) is like doublingthe distance from the noise.

67 dB(A)

100 ft

- 3 dB(A) = 64 dB(A)

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HIGHWAY TRAFFIC NOISEVehicle-generated noise comes from:

engine,exhaust system,

aerodynamic noisetire noise.

For > 50 mph, pavement/tire noise dominates.

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TIRE/PAVEMENT NOISEGENERATION

Source Generation MechanismsTread impact

At the interface between the tire and pavementan impact occurs as the tread hits the pavement.

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Within the contact patch, the passages and grooves in thetire are compressed anddistorted. The air entrained inthese passages will becompressed and pumped inand out. Because of aircompression effects and air

pumping, aerodynamicallygenerated sound is created.

Air pumping

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Slip-stickIf horizontal forces exceed the limits of friction, the

tread block will slip briefly and then re-stick to the pavement. This action of slipping and will generate both noise and vibration.

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Stick-snapThe contact between the tread block and the pavementcauses adhesion between the tread block and pavement.When the tread block exits the contact patch, theadhesive force holds the tread block. The release of the

tread block causes both sound energy and vibration ofthe tire carcass

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TIRE NOISE MEASUREMENTStatistical Passby : methods utilize a random sample of typical vehicles

measured one at a time.

The maximum sound pressure level is captured for each passby using a sound measurement system such as asound level meter (SLM).

The speed and vehicle type of each event is recorded. Astatistically significant sample of light and heavy vehiclesmust be collected. The data is used to compute a Statistical

Passby Index (SPBI)14


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The measurement site must be selected to avoid background noise, reflections, or terrain that mightaffect the measurement

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Close Proximity Methods (CPX):Close proximity methods (CPX) were developed toallow measurement to focus on tire/pavementinteraction noise.

The measurement is taken on a trailer, usingmicrophones located near the tire.The trailer includes a hood over the microphonessuch that wind noise is reduced and noise fromother traffic is reflected

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Asphalt mixtures1.Porous Asphalt Pavement

Porous pavements- constructed by reducing the amount ofsmall aggregate

Porosity reduces the strength of the air pumpingsource mechanism by preventing air compression

Porous pavements are capable of reducing

traffic noise, by absorbing sound .18


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Surface course: 50-100 mm porous or open-graded

asphalt mix.

Filter course: 50-75 mm opengraded crushed aggregate

provides filtering capabilitiesas well as a providing asuitable platform for paving

Reservoir course:50 75 mmsingle sized aggregates.

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2.Stone mastic asphalt (SMA) mixtures:

consist of a gap-graded aggregate with the upper sievesizes of 5.6 mmThe typical air void content of SMA mixtures is

between 1.5 and 3.0%, and the layer thickness is between 2 and 3 cm.The mixtures have both good mechanical performanceand friction properties, and are applicable for a normaltraffic load ;

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3.Portland cement porous pavement(PCPP)

sparse fine-aggregate content -void content in themixture can be as high as 15 30%.

This high void composition allows for noiseabsorption through the porous concrete.Pervious concrete Layer -12-25 cmBase coarse - min 15 cmSub-Base Layer - depends on infiltration rate

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Not for Heavy traffic Not for High speed road

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CONCLUSIONS

Quiet pavement that is safe, durable and economical has been demonstrated to be possible with current technology

The variation of available materials and constructiontechniques among the states mean that there is no generalguideline available yet for design of quiet pavement

The highway design engineer will need to select fromlocally available pavement type and texture that will

provide noise reduction using the principles described.24


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REFERENCE

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Tian, B., et. al., 2014, Reduction of Tire-PavementNoise by Porous Concrete Pavement, Journal ofMaterials in Civil Engineering, 26(1), 223-229.Rasmussen, R.O. and Sohaney, R.C., 2012, Tire-Pavement and Environmental Traffic Noise ResearchStudy, Colorado Department of Transportation Dtd

Applied Research and Innovation Branch, 20-40.Kandhal, P.S., 2004, Asphalt Pavement MitigateTire/Pavement noise, Hot Mix Asphalt Technology, 2-

8.Neithalath, N., Garcia, R. and Weiss, J., 2012, Tire-Pavement Interaction Noise: Recent Research onConcrete Pavement Surface Type and Texture, Journal of Materials in Civil Engineering, 6-18.


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Noiseless Pavements

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