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57-667: The La Mesa Dam and Reservoir is an earth dam in Quezon City , Philippines . Its reservoir can hold up to 50.5 million cubic meters (1,780 million cubic feet), occupying an area of 27 square kilometers (10 sq mi). It is part of the Angat - Ipo -La Mesa water system, which supplies most of the water in Metro Manila . The La Mesa Dam was constructed in 1929 as the Novaliches Reservoir during

114-402: 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

171-418: A dam and the filling of the reservoir behind it places a new weight on the floor and sides of a valley. The stress of the water increases linearly with its depth. Water also pushes against the upstream face of the dam, a nonrigid structure that under stress behaves semiplastically, and causes greater need for adjustment (flexibility) near the base of the dam than at shallower water levels. Thus the stress level of

228-422: A drain layer to collect seep water. A zoned-earth dam has distinct parts or zones of dissimilar material, typically a shell of locally plentiful material with a watertight clay core. Modern zoned-earth embankments employ filter and drain zones to collect and remove seep water and preserve the integrity of the downstream shell zone. An outdated method of zoned earth dam construction used a hydraulic fill to produce

285-448: A rock-fill dam, rock-fill is blasted using explosives to break the rock. Additionally, the rock pieces may need to be crushed into smaller grades to get the right range of size for use in an embankment dam. Earth-fill dams, also called earthen dams, rolled-earth dams or earth dams, are constructed as a simple embankment of well-compacted earth. A homogeneous rolled-earth dam is entirely constructed of one type of material but may contain

342-404: A small sustained overtopping flow can remove thousands of tons of overburden soil from the mass of the dam within hours. The removal of this mass unbalances the forces that stabilize the dam against its reservoir as the mass of water still impounded behind the dam presses against the lightened mass of the embankment, made lighter by surface erosion. As the mass of the dam erodes, the force exerted by

399-686: A thick suspension of earth, rocks and water. Therefore, safety requirements for the spillway are high, and require it to be capable of containing a maximum flood stage. It is common for its specifications to be written such that it can contain at least a one-hundred-year flood. A number of embankment dam overtopping protection systems were developed in the early 21st century. These techniques include concrete overtopping protection systems, timber cribs , sheet-piles , riprap and gabions , Reinforced Earth , minimum energy loss weirs , embankment overflow stepped spillways , and precast concrete block protection systems. All dams are prone to seepage underneath

456-590: A watertight core. Rolled-earth dams may also employ a watertight facing or core in the manner of a rock-fill dam. The frozen-core dam is a temporary earth dam occasionally used in high latitudes by circulating a coolant through pipes inside the dam to maintain a watertight region of permafrost within it. Tarbela Dam is a large dam on the Indus River in Pakistan , about 50 km (31 mi) northwest of Islamabad . Its height of 485 ft (148 m) above

513-454: 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

570-776: 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

627-602: Is an earth dam or a terrain dam ( caldera alike) with a height of 24 meters (79 ft). The elevation at its crest is 82.5 meters (271 ft) while the elevation at its overflow section is 80.15 meters (263.0 ft). These elevations can be observed from SM Fairview Mall , the Basement Level and First Floor at the Round about going bayan. The La Mesa Reservoir has a maximum capacity of about 50.5 million cubic meters (1,780 million cubic feet). Water from

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684-415: 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

741-473: 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

798-420: 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,

855-792: The American colonial era in the Philippines . Sometime between 1920 and 1926, the Metropolitan Water District (a predecessor agency of the Metropolitan Waterworks and Sewerage System ) decided to build a replacement for the old Wawa Dam in Montalban , Rizal . The Wawa Dam which served Manila and surrounding locales had to be replaced due to the growing population of the Manila area. The La Mesa Dam

912-454: 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 the process in the UK where the term tar macadam, shortened to tarmac was coined, after

969-490: The earth-filled dam (also called an earthen dam or terrain dam ) made of compacted earth, and the rock-filled dam . A cross-section of an embankment dam shows a shape like a bank, or hill. Most have a central section or core composed of an impermeable material to stop water from seeping through the dam. The core can be of clay, concrete, or asphalt concrete . This type of dam is a good choice for sites with wide valleys. They can be built on hard rock or softer soils. For

1026-406: 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

1083-489: The (DENR) and the Metropolitan Waterworks and Sewerage System (MWSS). The La Mesa Dam is part of the Angat - Ipo -La Mesa water system which supplies water to Metro Manila and surrounding provinces. The water collected in the reservoir is treated at the La Mesa and Balara Treatment Plants . The La Mesa facility has a designed capacity of 2,400 million litres per day (mld) and serves the western half of Metro Manila, while

1140-701: The Balara facility has a capacity of 1,600 mld and handles the remaining eastern section. Whenever the dam’s water level drops below the critical mark of 69 meters (226 ft), the MWSS, Maynilad , and Manila Water begin regulating water dispensed to customers. Because the dam is designed to overflow into the Tullahan River, the locations affected by spills from the dam in cases of extreme weather are Fairview, Valenzuela, Navotas, Quezon City and Malabon. Earth dam Embankment dams come in two types:

1197-604: 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

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1254-608: The U.S. Bureau of Reclamation 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 the core of embankment dams . Asphalt mixtures have been used in pavement construction since

1311-496: 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

1368-534: 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

1425-416: 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

1482-637: The asphalt make such dams especially suited to earthquake regions. For the Moglicë Hydro Power Plant in Albania the Norwegian power company Statkraft built an asphalt-core rock-fill dam. Upon completion in 2018 the 320 m long, 150 m high and 460 m wide dam is anticipated to be the world's highest of its kind. A concrete-face rock-fill dam (CFRD) is a rock-fill dam with concrete slabs on its upstream face. This design provides

1539-441: 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,

1596-549: The concrete slab as an impervious wall to prevent leakage and also a structure without concern for uplift pressure. In addition, the CFRD design is flexible for topography, faster to construct and less costly than earth-fill dams. The CFRD concept originated during the California Gold Rush in the 1860s when miners constructed rock-fill timber-face dams for sluice operations . The timber was later replaced by concrete as

1653-406: The core is separated using a filter. Filters are specifically graded soil designed to prevent the migration of fine grain soil particles. When suitable building material is at hand, transport is minimized, leading to cost savings during construction. Rock-fill dams are resistant to damage from earthquakes . However, inadequate quality control during construction can lead to poor compaction and sand in

1710-406: The dam must be calculated in advance of building to ensure that its break level threshold is not exceeded. Overtopping or overflow of an embankment dam beyond its spillway capacity will cause its eventual failure . The erosion of the dam's material by overtopping runoff will remove masses of material whose weight holds the dam in place and against the hydraulic forces acting to move the dam. Even

1767-490: The dam, but embankment dams are prone to seepage through the dam as well; for example, the Usoi landslide dam leaks 35-80 cubic meters per second. Sufficiently fast seepage can dislodge a dam's component particles, which results in faster seepage, which turns into a runaway feedback loop that can destroy the dam in a piping-type failure. Seepage monitoring is therefore an essential safety consideration. gn and Construction in

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1824-456: The design was applied to irrigation and power schemes. As CFRD designs grew in height during the 1960s, the fill was compacted and the slab's horizontal and vertical joints were replaced with improved vertical joints. In the last few decades, design has become popular. The tallest CFRD in the world is the 233 m-tall (764 ft) Shuibuya Dam in China , completed in 2008. The building of

1881-578: The embankment which can lead to liquefaction of the rock-fill during an earthquake. Liquefaction potential can be reduced by keeping susceptible material from being saturated, and by providing adequate compaction during construction. An example of a rock-fill dam is New Melones Dam in California or the Fierza Dam in Albania . A core that is growing in popularity is asphalt concrete . The majority of such dams are built with rock and/or gravel as

1938-508: 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

1995-691: 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

2052-414: 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

2109-400: 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

2166-416: 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

2223-498: 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

2280-424: 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

2337-409: 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

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2394-404: 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

2451-401: 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

2508-424: The primary fill. Almost 100 dams of this design have now been built worldwide since the first such dam was completed in 1962. All asphalt-concrete core dams built so far have an excellent performance record. The type of asphalt used is a viscoelastic - plastic material that can adjust to the movements and deformations imposed on the embankment as a whole, and to settlement of the foundation. The flexible properties of

2565-468: 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

2622-422: 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

2679-501: The reservoir begins to move the entire structure. The embankment, having almost no elastic strength, would begin to break into separate pieces, allowing the impounded reservoir water to flow between them, eroding and removing even more material as it passes through. In the final stages of failure, the remaining pieces of the embankment would offer almost no resistance to the flow of the water and continue to fracture into smaller and smaller sections of earth or rock until they disintegrate into

2736-613: The reservoir spills into the Tullahan River that passes Brgy. Nova Proper (commonly called Bayan) which transports the water to Manila Bay . The La Mesa Watershed Reservation which hosts the dam and reservoir is jointly administered, supervised, and controlled by the Department of Environment and Natural Resources of the Philippine national government and the is under the joint administration, supervision and control of

2793-399: The river bed and 95 sq mi (250 km ) reservoir make it the largest earth-filled dam in the world. The principal element of the project is an embankment 9,000 feet (2,700 m) long with a maximum height of 465 feet (142 m). The dam used approximately 200 million cubic yards (152.8 million cu. meters) of fill, which makes it one of the largest man-made structures in

2850-446: 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

2907-421: 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

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2964-398: 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

3021-404: 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

3078-404: The upstream face and made of masonry , concrete , plastic membrane, steel sheet piles, timber or other material. The impervious zone may also be inside the embankment, in which case it is referred to as a "core". In the instances where clay is used as the impervious material, the dam is referred to as a "composite" dam. To prevent internal erosion of clay into the rock fill due to seepage forces,

3135-530: 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

3192-414: The world. Because earthen dams can be constructed from local materials, they can be cost-effective in regions where the cost of producing or bringing in concrete would be prohibitive. Rock -fill dams are embankments of compacted free-draining granular earth with an impervious zone. The earth used often contains a high percentage of large particles, hence the term "rock-fill". The impervious zone may be on

3249-533: Was built in Novaliches, which was then in the municipality of Caloocan due to the sloping topography of the watershed area from Bulacan. The dam later became part of a larger system with the opening of Ipo Dam in Norzagaray , Bulacan in 1936, and Angat Dam in the same locale in 1967. The La Mesa Dam was raised in 1959 to increase the reservoir's maximum capacity to its current level. The La Mesa Dam

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