Buloba is an urban area in Wakiso District in the Buganda Region of Uganda . The area is primarily a middle-class residential neighborhood.
56-405: Buloba is on the tarmacked Kampala–Mityana Road . It is approximately 22 kilometres (14 mi), by road, west of Kampala , Uganda's capital and largest city. The coordinates of Buloba Main, immediately north of Buloba Police Station are 0°19'30.0"N, 32°27'26.0"E (Latitude:0.325000; Longitude:32.457222). Buloba lies at an average elevation of 1,170 metres (3,839 ft), above sea level. Buloba
112-402: A binder. The abbreviation, AC , is sometimes used for asphalt concrete but can also denote asphalt content or asphalt cement , referring to the liquid asphalt portion of the composite material. Mixing of asphalt and aggregate is accomplished in one of several ways: In addition to the asphalt and aggregate, additives, such as polymers , and antistripping agents may be added to improve
168-581: A campus of Africa Renewal University . Kasero Church of Uganda and St. Peter Catholic Church are also located here. Asphalt concrete Asphalt concrete (commonly called asphalt , blacktop , or pavement in North America, and tarmac or bitumen macadam in the United Kingdom and the Republic of Ireland) is a composite material commonly used to surface roads , parking lots , airports , and
224-438: A disproportionate amount of noise not only because of their large engines, but also the height of the diesel stack and the aerodynamic drag . Significant interior noise is usually present inside moving motor vehicles; in fact, passengers are generally not aware that these levels are high, because experience has led motorists to expect levels commonly exceeding 65 dBA . Roadway surface types contribute to different noise levels. Of
280-482: A few older noisier vehicles can dominate the soundscape. Small reductions in vehicle noise occurred in the 1970s as states and provinces enforced unmuffled vehicle ordinances. The vehicle fleet noise has not changed very much over the last three decades; however, if the trend in hybrid vehicle use continues, substantial noise reduction will occur, especially in the regime of traffic flow below 35 miles per hour. Hybrid vehicles are so quiet at low speeds that they create
336-487: A pedestrian safety issue when reversing or maneuvering when parking etc. (but not when travelling forward), and so are typically fitted with electric vehicle warning sounds . Traffic operations noise is affected significantly by vehicle speeds, since sound energy roughly doubles for each increment of ten miles an hour in vehicle velocity; an exception to this rule occurs at very low speeds where braking and acceleration noise dominate over aerodynamic noise. Trucks contribute
392-561: A range of strategies for incorporating waste materials into asphalt concrete. The strategies presented in the study include the use of plastics, particularly high-density polyethylene, in asphalt binders, and the use of glass, brick, ceramic, and marble quarry waste in place of traditional aggregate. Rejuvenators may also be produced from recycled materials, including waste engine oil, waste vegetable oil, and waste vegetable grease. Recently, discarded face masks have been incorporated into stone mastic. Roadway noise Roadway noise
448-400: A statistical manner allowing for actual wind rose and wind speed statistics (along with thermocline data). Recent models have also attempted to predict levels of local air pollution based on an analysis of specific frequencies that are related to tire and engine noise. An interesting early case where two of the leading models were pitted against each other involved a proposed widening of
504-454: Is a maintenance measure that helps keep water and petroleum products out of the pavement. Maintaining and cleaning ditches and storm drains will extend the life of the road at low cost. Sealing small cracks with bituminous crack sealer prevents water from enlarging cracks through frost weathering, or percolating down to the subbase and softening it. For somewhat more distressed roads, a chip seal or similar surface treatment may be applied. As
560-772: Is a research program by the FHWA , which is specifically focusing on long-term pavement behaviour. Asphalt deterioration can include crocodile cracking , potholes , upheaval, raveling , bleeding , rutting , shoving, stripping , and grade depressions. In cold climates, frost heaves can crack asphalt even in one winter. Filling the cracks with bitumen is a temporary fix, but only proper compaction and drainage can slow this process. Factors that cause asphalt concrete to deteriorate over time mostly fall into one of three categories: construction quality, environmental considerations, and traffic loads. Often, damage results from combinations of factors in all three categories. Construction quality
616-415: Is critical to pavement performance. This includes the construction of utility trenches and appurtenances that are placed in the pavement after construction. Lack of compaction in the surface of the asphalt, especially on the longitudinal joint, can reduce the life of a pavement by 30 to 40%. Service trenches in pavements after construction have been said to reduce the life of the pavement by 50%, mainly due to
SECTION 10
#1732876059321672-450: Is divided into four administrative zones, from east to west: (a) Buloba ku Mwenda ("Buloba Nine Miles"), approximately 9 miles (14 km) west of Kampala (b) Buloba Kasero, about 10.5 miles (17 km) west of Kampala (c) Buloba Main, about 12 miles (19 km) west of Kampala and (d) Buloba Kiweesa, about 14 miles (23 km) west of Kampala. The neighborhood of Buloba has an estimated size of 1,295 hectares (3,200 acres) or 13 km2. When
728-473: Is found on interstate highways where maintenance is highly crucial. Asphalt concrete generates less roadway noise than a Portland cement concrete surface, and is typically less noisy than chip seal surfaces. Because tire noise is generated through the conversion of kinetic energy to sound waves , more noise is produced as the speed of a vehicle increases. The notion that highway design might take into account acoustical engineering considerations, including
784-633: Is made by adding ground up tires to asphalt paving material. Studies have shown that cutting longitudinal grooves in the pavement reduces noise. Tire types can cause 10 dB(A) variations in noise, based on a 2001 sample of 100 commercially available tires. As of 2001, there was no correlation between grip and noise. Quieter tires may have slightly lower rolling resistance. Tire labeling for noise, grip, and rolling resistance has been widely introduced in Europe, with noisy tires being taxed. Roadway geometrics and surrounding terrain are interrelated, since
840-459: Is required for national and worldwide responses to road noise pollution - issues include road surface choices, the regulation and taxing of noisy designs, and the ongoing inspecting of individual vehicles. At the micro level of managing particular roads, because of the complexity of the variables discussed above, it is necessary to create a computer model that can analyze sound levels in the vicinity of roadways. The first meaningful models arose in
896-424: Is significant in that sound waves can be refracted by wind gradients or thermoclines , effectively dismissing the effect of some noise barriers or terrain intervention. Geometry of area structures is an important input, since the presence of buildings or walls can block sound under certain circumstances, but reflective properties can augment sound energy at other locations. At a macro level, ongoing research
952-420: Is the collective sound energy emanating from motor vehicles . It consists chiefly of road surface , tire, engine /transmission, aerodynamic, and braking elements. Noise of rolling tires driving on pavement is found to be the biggest contributor of highway noise and increases with higher vehicle speeds. In developed and developing countries , roadway noise contributes a proportionately large share of
1008-420: Is why some agencies place the priority on preventive maintenance of roads in good condition, rather than reconstructing roads in poor condition. Poor roads are upgraded as resources and budget allow. In terms of lifetime cost and long term pavement conditions, this will result in better system performance. Agencies that concentrate on restoring their bad roads often find that by the time they have repaired them all,
1064-713: The Uganda Oil Refinery is built, it is anticipated that Hoima–Kampala Petroleum Products Pipeline , the refined petroleum products will be piped to a location near Buloba, for distribution within Kampala and other towns such as Entebbe . Buloba Police Station, an establishment of the Uganda Police Force , is located in "Buloba Main". Health facilities include Buloba Health Centre and Lynaset Health Care Services. The neighborhood also hosts Buloba High School, Buloba Teacher's Training College, Buloba Vocational Institute and
1120-406: The subsoil to see how much load it can withstand. The pavement and subbase thicknesses are designed to withstand the wheel loads. Sometimes, geogrids are used to reinforce the subbase and further strengthen the roads. Drainage, including ditches , storm drains and underdrains are used to remove water from the roadbed, preventing it from weakening the subbase and subsoil. Sealcoating asphalt
1176-586: The Department of Transportation to incorporate crumb rubber into asphalt paving materials. Other recycled materials that are actively included in asphalt concrete mixes across the United States include steel slag, blast furnace slag, and cellulose fibers. Further research has been conducted to discover new forms of waste that may be recycled into asphalt mixes. A 2020 study conducted in Melbourne, Australia presented
SECTION 20
#17328760593211232-615: The New Jersey Turnpike from six to twelve lanes. The BBN and ESL models were on opposing sides of a matter decided in New Jersey Superior Court. This case in the early 1970s was one of the first U.S. examples of acoustical scientists playing a role in the design of a major highway. The models allowed the court to understand the effects of roadway geometry (width in this case), vehicle speeds, proposed noise barriers , residential setback and pavement types. The outcome
1288-449: The U.S. In developing countries, noise pollution from motor vehicles represents a significant impact, but technologies are not as advanced as in Western nations. For example, a recent paper from Iran illustrates a level of technology that the United States encountered in the 1960s. The European Union has recently proposed a set of vehicle tire requirements, similar to those introduced in
1344-496: The United States contained, on average, 21.1% RAP and 0.2% RAS. Recycled asphalt components may be reclaimed and transported to an asphalt plant for processing and use in new pavements, or the entire recycling process may be conducted in-place. While in-place recycling typically occurs on roadways and is specific to RAP, recycling in asphalt plants may utilize RAP, RAS, or both. In 2019, an estimated 97.0 million tons of RAP and 1.1 million tons of RAS were accepted by asphalt plants in
1400-534: The United States. RAP is typically received by plants after being milled on-site, but pavements may also be ripped out in larger sections and crushed in the plant. RAP millings are typically stockpiled at plants before being incorporated into new asphalt mixes. Prior to mixing, stockpiled millings may be dried and any that have agglomerated in storage may have to be crushed. RAS may be received by asphalt plants as post-manufacturer waste directly from shingle factories, or they may be received as post-consumer waste at
1456-416: The United States. Many roofing shingles also contain asphalt, and asphalt concrete mixes may contain reclaimed asphalt shingles (RAS). Research has demonstrated that RAP and RAS can replace the need for up to 100% of the virgin aggregate and asphalt binder in a mix, but this percentage is typically lower due to regulatory requirements and performance concerns. In 2019, new asphalt pavement mixtures produced in
1512-427: The accuracy of early models has had little change in 40 years. Generally the models trace sound ray bundles and calculate spreading loss along with ray bundle divergence (or convergence) from refractive phenomena. Diffraction is usually addressed by establishing secondary emitters at any points of topographic or anthropomorphic “sharpness” (such as noise barriers or building surfaces). Meteorology can be addressed in
1568-441: The asphalt to oxidize, becoming stiffer and less resilient, leading to crack formation. Cold temperatures can cause cracks as the asphalt contracts. Cold asphalt is also less resilient and more vulnerable to cracking. Water trapped under the pavement softens the subbase and subgrade, making the road more vulnerable to traffic loads. Water under the road freezes and expands in cold weather, causing and enlarging cracks. In spring thaw,
1624-465: The common types of surfaces in modern cities, there is a 4 dB difference between the loudest and the softest: chip seal type and grooved roads being the loudest , and concrete surfaces without spacers being the quietest, and asphaltic surfaces being about average. Rubberized asphalt (which uses recycled old tires) is much quieter and is already widely used. Experimental Porous Elastic Road Surfaces (PERS) might cut road noise in half. PERS
1680-413: The core of embankment dams . Asphalt mixtures have been used in pavement construction since the beginning of the twentieth century. It consists of mineral aggregate bound together with bitumen (a substance also independently known as asphalt), laid in layers, and compacted. The process was refined and enhanced by Belgian-American inventor Edward De Smedt . Edgar Purnell Hooley further enhanced
1736-508: The end of their service life. Processing of RAS includes grinding the shingles and sieving the grinds to remove oversized particles. The grinds may also be screened with a magnetic sieve to remove nails and other metal debris. The ground RAS is then dried, and the asphalt cement binder can be extracted. For further information on RAS processing, performance, and associated health and safety concerns, see Asphalt Shingles . In-place recycling methods allow roadways to be rehabilitated by reclaiming
Buloba - Misplaced Pages Continue
1792-691: The existing pavement, remixing, and repaving on-site. In-place recycling techniques include rubblizing , hot in-place recycling, cold in-place recycling, and full-depth reclamation . For further information on in-place methods, see Road Surface . During its service life, the asphalt cement binder, which makes up about 5–6% of a typical asphalt concrete mix, naturally hardens and becomes stiffer. This aging process primarily occurs due to oxidation, evaporation, exudation, and physical hardening. For this reason, asphalt mixes containing RAP and RAS are prone to exhibiting lower workability and increased susceptibility to fatigue cracking. These issues are avoidable if
1848-414: The friction course. In general, the viscosity of asphalt allows it to conveniently form a convex surface, and a central apex to streets and roads to drain water to the edges. This is not, however, in itself an advantage over concrete, which has various grades of viscosity and can be formed into a convex road surface. Rather, it is the economy of asphalt concrete that renders it more frequently used. Concrete
1904-400: The ground thaws from the top down, so water is trapped between the pavement above and the still-frozen soil underneath. This layer of saturated soil provides little support for the road above, leading to the formation of potholes. This is more of a problem for silty or clay soils than sandy or gravelly soils. Some jurisdictions pass frost laws to reduce the allowable weight of trucks during
1960-416: The lack of compaction in the trench, and also because of water intrusion through improperly sealed joints. Environmental factors include heat and cold, the presence of water in the subbase or subgrade soil underlying the pavement, and frost heaves. High temperatures soften the asphalt binder, allowing heavy tire loads to deform the pavement into ruts. Paradoxically, high heat and strong sunlight also cause
2016-536: The late 1960s and early 1970s addressing the noise line source (e.g. roadway). Two of the leading research teams were BBN in Boston and ESL of Sunnyvale, California . Both of these groups developed complex mathematical models to allow the study of alternate roadway designs, traffic operations and noise mitigation strategies in an arbitrary setting. Later model alterations have come into widespread use among state departments of transportation and city planners, but
2072-498: The mix's rutting resistance while maintaining adequate fatigue cracking resistance. In mixes with higher recycled content, the addition of virgin binder becomes less effective, and rejuvenators may be used. Rejuvenators are additives that restore the physical and chemical properties of the aged binder. When conventional mixing methods are used in asphalt plants, the upper limit for RAP content before rejuvenators become necessary has been estimated at 50%. Research has demonstrated that
2128-409: The number, width and length of cracks increases, more intensive repairs are needed. In order of generally increasing expense, these include thin asphalt overlays, multicourse overlays, grinding off the top course and overlaying, in-place recycling, or full-depth reconstruction of the roadway. It is far less expensive to keep a road in good condition than it is to repair it once it has deteriorated. This
2184-442: The other hand, individual owners of motorbikes, 'boom-box' cars (with very loud music systems), and 'muscle-cars' may prefer their vehicle to be louder (at least at idling or low speeds), and such noise (often from modified exhaust systems) can only be controlled by on-going inspection and sanctions. Several studies have concluded that reducing traffic noise pollution is low-cost or cost-effective. Such studies include consideration of
2240-404: The pavement for controlling storm water. Different types of asphalt concrete have different performance characteristics in roads in terms of surface durability, tire wear, braking efficiency and roadway noise . In principle, the determination of appropriate asphalt performance characteristics must take into account the volume of traffic in each vehicle category, and the performance requirements of
2296-401: The performance aspects of RAP and RAS is to combine the recycled components with virgin aggregate and virgin asphalt binder. This approach can be effective when the recycled content in the mix is relatively low, and has a tendency to work more effectively with soft virgin binders. A 2020 study found that the addition of 5% RAS to a mix with a soft, low-grade virgin binder significantly increased
Buloba - Misplaced Pages Continue
2352-593: The planning of new roadways and the design of noise mitigation . Partial bans on motor vehicles from urban areas have been shown to have minimal impacts upon reducing sound levels (as would become clear from later modeling studies); for example, the partial ban in Gothenburg, Sweden resulted in minuscule reduction of sound levels. Regulation in the EU and Japan of tire and power-train noise has only sought to reduce noise by approx 3 dB, and will only slowly take effect because
2408-557: The process in the UK where the term tar macadam, shortened to tarmac was coined, after the name of his company Tar Macadam (Purnell Hooley's Patent) Syndicate Limited derived from the combination of tar and Macadam gravel composite mixtures. The terms asphalt (or asphaltic ) concrete , bituminous asphalt concrete , and bituminous mixture are typically used only in engineering and construction documents, which define concrete as any composite material composed of mineral aggregate adhered with
2464-523: The propagation of sound is sensitive to the overall geometry and must consider diffraction (bending of sound waves around obstacles), reflection , ground wave attenuation, spreading loss and refraction . A simple discussion indicates that sound will be diminished when the path of sound is blocked by terrain, or will be enhanced if the roadway is elevated so as to broadcast; however, the complexities of variable interaction are so great, that there are many exceptions to this simple argument. Micrometeorology
2520-468: The properties of the final product. Areas paved with asphalt concrete—especially airport aprons —have been called "the tarmac" at times, despite not being constructed using the tarmacadam process. A variety of specialty asphalt concrete mixtures have been developed to meet specific needs, such as stone-matrix asphalt , which is designed to ensure a strong wearing surface, or porous asphalt pavements, which are permeable and allow water to drain through
2576-422: The recycled components are apportioned correctly in the mix. Practicing proper storage and handling, such as by keeping RAP stockpiles out of damp areas or direct sunlight, is also important in avoiding quality issues. The binder aging process may also produce some beneficial attributes, such as by contributing to higher levels of rutting resistance in asphalts containing RAP and RAS. One approach to balancing
2632-411: The reduced value of noise-affected real-estate, the costs of supporting a dispersed population 'trying to get away from all the noise', and the increased healthcare costs statistically attributable to a noisier environment. European technology began to emulate the United States treatment of roadway noise by the 1980s, although the national requirements of noise studies generally remain less stringent than
2688-446: The road over a longer period of time, increasing ruts, cracking, and corrugations in the asphalt pavement. Other causes of damage include heat damage from vehicle fires, or solvent action from chemical spills. The life of a road can be prolonged through good design, construction and maintenance practices. During design, engineers measure the traffic on a road, paying special attention to the number and types of trucks. They also evaluate
2744-421: The roads that were in good condition have deteriorated. Some agencies use a pavement management system to help prioritize maintenance and repairs. Asphalt concrete is a recyclable material that can be reclaimed and reused both on-site and in asphalt plants . The most common recycled component in asphalt concrete is reclaimed asphalt pavement (RAP). RAP is recycled at a greater rate than any other material in
2800-398: The selection of the type of surface paving, arose in the early 1970s. With regard to structural performance, the asphalt behaviour depends on a variety of factors including the material, loading and environmental condition. Furthermore, the performance of pavement varies over time. Therefore, the long-term behaviour of asphalt pavement is different from its short-term performance. The LTPP
2856-404: The spring thaw season and protect their roads. The damage a vehicle causes is roughly proportional to the axle load raised to the fourth power, so doubling the weight an axle carries actually causes 16 times as much damage. Wheels cause the road to flex slightly, resulting in fatigue cracking, which often leads to crocodile cracking. Vehicle speed also plays a role. Slowly moving vehicles stress
SECTION 50
#17328760593212912-559: The total societal noise pollution . In the U.S., it contributes more to environmental noise exposure than any other noise source. Roadway noise began to be measured in a widespread manner in the 1960s, as computer modeling of this phenomenon began to become meaningful. After passage of the National Environmental Policy Act and Noise Control Act , the demand for detailed analysis soared, and decision makers began to look to acoustical scientists for answers regarding
2968-527: The use of rejuvenators at optimal doses can allow for mixes with 100% recycled components to meet the performance requirements of conventional asphalt concrete. Beyond RAP and RAS, a range of waste materials can be re-used in place of virgin aggregate, or as rejuvenators. Crumb rubber, generated from recycled tires, has been demonstrated to improve the fatigue resistance and flexural strength of asphalt mixes that contain RAP. In California, legislative mandates require
3024-450: The value of acoustical science to provide useful insights to the roadway design process. Even without regulation, there are strong individual economic pressures for quieter vehicles, because owners and employers see quieter vehicles as more luxurious and less stressful. The tighter regulatory requirements of the EU and Japan encourage quieter design even in unregulated countries, because most car manufacturers aspire to international sales. On
3080-507: Was a compromise that involved substantial mitigation of noise pollution impacts. Another early case involved the proposed extension of Interstate 66 through Arlington, Virginia . The plaintiff , Arlington Coalition on Transportation sued the Virginia Department of Transportation on the grounds of air quality , noise and neighborhood disruption. To analyze roadway noise, the ESL model
3136-426: Was used by the plaintiff, who won this case partially due to the credibility of the computer model. The matter was revisited a decade later and a greatly reduced highway design with transit element and extensive noise mitigation was agreed to. Later cases have occurred in every state, both in contentious actions and in routine highway planning and design. The public as well as governmental agencies have become aware of
#320679