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75-912: The stream rises on the grounds of the Chevy Chase Country Club and flows through Chevy Chase to the Somerset neighborhood, where it crosses through Vinton Park and the Willard Avenue Park. After crossing under the Little Falls Parkway it joins Willett Branch and then flows through the Little Falls Stream Valley Park to Brookmont, the Chesapeake and Ohio Canal and into the Potomac River . The name, "Powder Mill Branch"

150-411: A calcium aluminate cement or with Portland cement to form Portland cement concrete (named for its visual resemblance to Portland stone ). Many other non-cementitious types of concrete exist with other methods of binding aggregate together, including asphalt concrete with a bitumen binder, which is frequently used for road surfaces , and polymer concretes that use polymers as a binder. Concrete

225-589: A 20 acre purchase on both sides of Massachusetts avenue in 1946. In 1948, the Maryland-National Capital Park and Planning Commission was authorized to purchase parkland around Little Falls Branch and Willett Branch under the Capper-Cramton Act of 1930. The Little Falls Parkway was eventually built from Glenbrook Road to Massachusetts Avenue , but plans to extend the parkway south to MacArthur Boulevard were dropped in 1970 and

300-433: A French structural and civil engineer . Concrete components or structures are compressed by tendon cables during, or after, their fabrication in order to strengthen them against tensile forces developing when put in service. Freyssinet patented the technique on 2 October 1928. Concrete is an artificial composite material , comprising a matrix of cementitious binder (typically Portland cement paste or asphalt ) and

375-778: A campus in Chevy Chase. For decades, a six-block stretch of Wisconsin Avenue in Friendship Heights and Chevy Chase has been the only place partially or wholly in Washington, D.C., with multiple traditional department stores , namely, Bloomingdale's , Saks Fifth Avenue , Lord & Taylor and Neiman Marcus . The latter two closed in 2020, as did the indoor shopping center at the Chevy Chase Pavilion. As of 2022, two department stores remain, both on

450-452: A cementitious material forms a cement paste by the process of hydration. The cement paste glues the aggregate together, fills voids within it, and makes it flow more freely. As stated by Abrams' law , a lower water-to-cement ratio yields a stronger, more durable concrete, whereas more water gives a freer-flowing concrete with a higher slump . The hydration of cement involves many concurrent reactions. The process involves polymerization ,

525-400: A concrete component—and become a part of the binder for the aggregate. Fly ash and slag can enhance some properties of concrete such as fresh properties and durability. Alternatively, other materials can also be used as a concrete binder: the most prevalent substitute is asphalt , which is used as the binder in asphalt concrete . Admixtures are added to modify the cure rate or properties of

600-434: A dispersed phase or "filler" of aggregate (typically a rocky material, loose stones, and sand). The binder "glues" the filler together to form a synthetic conglomerate . Many types of concrete are available, determined by the formulations of binders and the types of aggregate used to suit the application of the engineered material. These variables determine strength and density, as well as chemical and thermal resistance of

675-452: A greater degree of fracture resistance even in seismically active environments. Roman concrete is significantly more resistant to erosion by seawater than modern concrete; it used pyroclastic materials which react with seawater to form Al- tobermorite crystals over time. The use of hot mixing and the presence of lime clasts are thought to give the concrete a self-healing ability, where cracks that form become filled with calcite that prevents

750-822: A hotel at 7100 Connecticut Avenue; it opened it in 1894 as the Chevy Chase Spring Hotel and was later renamed the Chevy Chase Inn. "The hotel failed to attract sufficient patrons, especially during the winter months," wrote the Chevy Chase Historical Society, and in 1895, the Land Company leased the property for a year to the Young Ladies Seminary. Part of the original Cheivy Chace patent had been sold to Abraham Bradley , who built an estate known as

825-415: A large aggregate that is too large for the size of the formwork, or which has too few smaller aggregate grades to serve to fill the gaps between the larger grades, or using too little or too much sand for the same reason, or using too little water, or too much cement, or even using jagged crushed stone instead of smoother round aggregate such as pebbles. Any combination of these factors and others may result in

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900-461: A large type of industrial facility called a concrete plant , or often a batch plant. The usual method of placement is casting in formwork , which holds the mix in shape until it has set enough to hold its shape unaided. Concrete plants come in two main types, ready-mix plants and central mix plants. A ready-mix plant blends all of the solid ingredients, while a central mix does the same but adds water. A central-mix plant offers more precise control of

975-480: A late-19th-century effort to create a new suburb that its developer dubbed Chevy Chase after a colonial land patent . Primarily residential, Chevy Chase adjoins Friendship Heights , a popular shopping district. It is the home of the Chevy Chase Club and Columbia Country Club , private clubs whose members include many prominent politicians and Washingtonians. The name is derived from Cheivy Chace ,

1050-469: A mixture of calcium silicates ( alite , belite ), aluminates and ferrites —compounds, which will react with water. Portland cement and similar materials are made by heating limestone (a source of calcium) with clay or shale (a source of silicon, aluminium and iron) and grinding this product (called clinker ) with a source of sulfate (most commonly gypsum ). Cement kilns are extremely large, complex, and inherently dusty industrial installations. Of

1125-405: A number of manufactured aggregates, including air-cooled blast furnace slag and bottom ash are also permitted. The size distribution of the aggregate determines how much binder is required. Aggregate with a very even size distribution has the biggest gaps whereas adding aggregate with smaller particles tends to fill these gaps. The binder must fill the gaps between the aggregate as well as paste

1200-424: A semi-liquid slurry (paste) that can be shaped, typically by pouring it into a form. The concrete solidifies and hardens through a chemical process called hydration . The water reacts with the cement, which bonds the other components together, creating a robust, stone-like material. Other cementitious materials, such as fly ash and slag cement , are sometimes added—either pre-blended with the cement or directly as

1275-493: A simple, fast way of getting a basic idea of the properties of the finished concrete without having to perform testing in advance. Various governing bodies (such as British Standards ) define nominal mix ratios into a number of grades, usually ranging from lower compressive strength to higher compressive strength. The grades usually indicate the 28-day cure strength. Thorough mixing is essential to produce uniform, high-quality concrete. Separate paste mixing has shown that

1350-406: A solid over time. Concrete is the second-most-used substance in the world after water , and is the most widely used building material. Its usage worldwide, ton for ton, is twice that of steel, wood, plastics, and aluminium combined. When aggregate is mixed with dry Portland cement and water , the mixture forms a fluid slurry that is easily poured and molded into shape. The cement reacts with

1425-511: Is distinct from mortar . Whereas concrete is itself a building material, mortar is a bonding agent that typically holds bricks , tiles and other masonry units together. Grout is another material associated with concrete and cement. It does not contain coarse aggregates and is usually either pourable or thixotropic , and is used to fill gaps between masonry components or coarse aggregate which has already been put in place. Some methods of concrete manufacture and repair involve pumping grout into

1500-519: Is served by the Montgomery County Public Schools . Residents of Chevy Chase are zoned to Somerset, Chevy Chase or North Chevy Chase Elementary School, which feed into Silver Creek Middle School, Westland Middle School and Bethesda-Chevy Chase High School . Private schools in Chevy Chase include Concord Hill School, Oneness-Family School , and Blessed Sacrament School. Rochambeau French International School formerly had

1575-559: Is then blended with aggregates and any remaining batch water and final mixing is completed in conventional concrete mixing equipment. Workability is the ability of a fresh (plastic) concrete mix to fill the form/mold properly with the desired work (pouring, pumping, spreading, tamping, vibration) and without reducing the concrete's quality. Workability depends on water content, aggregate (shape and size distribution), cementitious content and age (level of hydration ) and can be modified by adding chemical admixtures, like superplasticizer. Raising

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1650-399: Is usually reinforced with materials that are strong in tension, typically steel rebar . The mix design depends on the type of structure being built, how the concrete is mixed and delivered, and how it is placed to form the structure. Portland cement is the most common type of cement in general usage. It is a basic ingredient of concrete, mortar , and many plasters . It consists of

1725-633: The United States District Court for the District of Columbia . When the trail design was approved from Bradley Boulevard to Albemarle Street, the neighborhood group sued again. In 1980 the Washington Suburban Sanitary Commission built the sewer line through the park, replacing one that was leaking and in 1981 a bike trail was added on top of it. The bike trail was originally planned to follow

1800-480: The construction industry , whose demand is ever growing with greater impacts on raw material extraction, waste generation and landfill practices. Concrete production is the process of mixing together the various ingredients—water, aggregate, cement, and any additives—to produce concrete. Concrete production is time-sensitive. Once the ingredients are mixed, workers must put the concrete in place before it hardens. In modern usage, most concrete production takes place in

1875-495: The watershed . 38°56′08″N 77°07′11″W  /  38.935667°N 77.119701°W  / 38.935667; -77.119701 Chevy Chase, Maryland Chevy Chase ( / ˈ tʃ ɛ v iː tʃ eɪ s / ) is the colloquial name of an area that includes a town , several incorporated villages , and an unincorporated census-designated place in southern Montgomery County , Maryland ; and one adjoining neighborhood in northwest Washington, D.C. Most of these derive from

1950-558: The Bradley Farm. In 1892, Newlands and other members of the Metropolitan Club of Washington, D.C., founded a hunt club called Chevy Chase Hunt, which would later become Chevy Chase Club. In 1894, the club located itself on the former Bradley Farm property under a lease from its owners. The club introduced a six-hole golf course to its members in 1895, and purchased the 9.36-acre Bradley Farm tract in 1897. In 1906,

2025-563: The Chevy Chase Country Club barred "Negroes" and "one ethnic group of Caucasians" from membership. In response, Club president Randall H. Hagnar denied that the club excluded Black or Jewish people; he said that no members were African-Americans but that several were Jewish. In 1903, Lea M. Bouligny bought the old Chevy Chase Inn and founded the Chevy Chase College and Seminary . The name was changed to Chevy Chase Junior College in 1927. The National 4-H Club Foundation purchased

2100-501: The Chevy Chase Land Company blocked a proposed subdivision called Belmont after they learned its Black developers aimed to sell house lots to other African Americans. In subsequent litigation, the company and its affiliates argued that those developers had committed fraud by proposing "to sell lots...to negroes." By the 1920s, restrictive covenants were added to Chevy Chase real estate deeds. Some prohibited both

2175-561: The Dalecarlia drinking water treatment plant in Washington, D.C., and occasionally has received overflow discharges from the plant. According to a study conducted by the county government, the water quality of the stream and its tributaries is poor, due to water pollution from urban runoff , as well as the channelization described above. The county and the Town of Somerset have installed several stream restoration projects throughout

2250-595: The Dalecarlia Reservoir and the branch stopped providing water to the city. In 1897, the Department of Agriculture purchased a farm located along a tributary of Little Falls Branch from Henry Bradley Davidson for use by the Bureau of Animal Indusctry's animal disease station. It was used until the 1930s when sub-urbanization brought neighbors who complained about the smells. It was moved to Beltsville and

2325-658: The District of Columbia, for the purpose of developing a residential streetcar suburb for Washington, D.C. , during the expansion of the Washington streetcars system. Newlands and his partners founded The Chevy Chase Land Company in 1890, and its holdings of more than 1,700 acres (6.9 km ) eventually extended along the present-day Connecticut Avenue from Florida Avenue north to Jones Bridge Road. Newlands, an avowed white supremacist , and his development company took steps to ensure that residents of its new suburbs would be wealthy and white; for example, "requiring, in

Little Falls Branch (Potomac River tributary) - Misplaced Pages Continue

2400-464: The Maryland side: a freestanding Saks Fifth Avenue and a Bloomingdale's in a multiuse center that also includes a Whole Foods Market , boutiques, and residential and office space. Along the D.C. stretch of Wisconsin Avenue are: On the Maryland stretch are: Concrete Concrete is a composite material composed of aggregate bonded together with a fluid cement that cures to

2475-643: The absence of reinforcement, its tensile strength was far lower than modern reinforced concrete , and its mode of application also differed: Modern structural concrete differs from Roman concrete in two important details. First, its mix consistency is fluid and homogeneous, allowing it to be poured into forms rather than requiring hand-layering together with the placement of aggregate, which, in Roman practice, often consisted of rubble . Second, integral reinforcing steel gives modern concrete assemblies great strength in tension, whereas Roman concrete could depend only upon

2550-472: The area turned into a park. In 1951 it was transferred from the Department of Agriculture to the Maryland-National Capital Park and Planning Commission which first added it to the Little Falls Parkway, but then turned it into Norwood Park, named for the nearby St. John's Episcopal Church, Norwood Parish. Planning for the Little Falls parkway started in the mid-1940's and the county began buying land with

2625-630: The cisterns secret as these enabled the Nabataeans to thrive in the desert. Some of these structures survive to this day. In the Ancient Egyptian and later Roman eras, builders discovered that adding volcanic ash to lime allowed the mix to set underwater. They discovered the pozzolanic reaction . The Romans used concrete extensively from 300 BC to AD 476. During the Roman Empire, Roman concrete (or opus caementicium )

2700-604: The completion of the Washington Aqueduct , the Potomac River became the city's principal water source, instead of Little Falls Branch; however, muddy water from Little Falls Branch continued to flow into the reservoir, and a bypass pipe was built to channel the aqueduct water to another city reservoir, the Georgetown Reservoir . In 1895 construction was completed to fully divert the stream from

2775-526: The concrete at the time of batching/mixing. (See § Production below.) The common types of admixtures are as follows: Inorganic materials that have pozzolanic or latent hydraulic properties, these very fine-grained materials are added to the concrete mix to improve the properties of concrete (mineral admixtures), or as a replacement for Portland cement (blended cements). Products which incorporate limestone , fly ash , blast furnace slag , and other useful materials with pozzolanic properties into

2850-399: The concrete can cause the initially placed material to begin to set before the next batch is added on top. This creates a horizontal plane of weakness called a cold joint between the two batches. Once the mix is where it should be, the curing process must be controlled to ensure that the concrete attains the desired attributes. During concrete preparation, various technical details may affect

2925-461: The concrete quality. Central mix plants must be close to the work site where the concrete will be used, since hydration begins at the plant. A concrete plant consists of large hoppers for storage of various ingredients like cement, storage for bulk ingredients like aggregate and water, mechanisms for the addition of various additives and amendments, machinery to accurately weigh, move, and mix some or all of those ingredients, and facilities to dispense

3000-528: The crack from spreading. The widespread use of concrete in many Roman structures ensured that many survive to the present day. The Baths of Caracalla in Rome are just one example. Many Roman aqueducts and bridges, such as the magnificent Pont du Gard in southern France, have masonry cladding on a concrete core, as does the dome of the Pantheon . After the Roman Empire, the use of burned lime and pozzolana

3075-481: The deed to the land, that only a single-family detached house costing a large amount of money could be constructed. The Chevy Chase Land Company did not include explicit bars against non-white people, known as racial covenants, but the mandated cost of the house made it impractical for all but the wealthiest non-white people to buy the land." Houses were required to cost $ 5,000 and up on Connecticut Avenue and $ 3,000 and up on side streets. The company banned commerce from

Little Falls Branch (Potomac River tributary) - Misplaced Pages Continue

3150-431: The finished product. Construction aggregates consist of large chunks of material in a concrete mix, generally a coarse gravel or crushed rocks such as limestone , or granite , along with finer materials such as sand . Cement paste, most commonly made of Portland cement , is the most prevalent kind of concrete binder. For cementitious binders, water is mixed with the dry cement powder and aggregate, which produces

3225-681: The gaps to make up a solid mass in situ . The word concrete comes from the Latin word " concretus " (meaning compact or condensed), the perfect passive participle of " concrescere ", from " con -" (together) and " crescere " (to grow). Concrete floors were found in the royal palace of Tiryns , Greece, which dates roughly to 1400 to 1200 BC. Lime mortars were used in Greece, such as in Crete and Cyprus, in 800 BC. The Assyrian Jerwan Aqueduct (688 BC) made use of waterproof concrete . Concrete

3300-554: The interlinking of the silicates and aluminate components as well as their bonding to sand and gravel particles to form a solid mass. One illustrative conversion is the hydration of tricalcium silicate: The hydration (curing) of cement is irreversible. Fine and coarse aggregates make up the bulk of a concrete mixture. Sand , natural gravel, and crushed stone are used mainly for this purpose. Recycled aggregates (from construction, demolition, and excavation waste) are increasingly used as partial replacements for natural aggregates, while

3375-406: The making of mortar. In an English translation from 1397, it reads "lyme ... is a stone brent; by medlynge thereof with sonde and water sement is made". From the 14th century, the quality of mortar was again excellent, but only from the 17th century was pozzolana commonly added. The Canal du Midi was built using concrete in 1670. Perhaps the greatest step forward in the modern use of concrete

3450-531: The material. Mineral admixtures use recycled materials as concrete ingredients. Conspicuous materials include fly ash , a by-product of coal-fired power plants ; ground granulated blast furnace slag , a by-product of steelmaking ; and silica fume , a by-product of industrial electric arc furnaces . Structures employing Portland cement concrete usually include steel reinforcement because this type of concrete can be formulated with high compressive strength , but always has lower tensile strength . Therefore, it

3525-419: The mix, are being tested and used. These developments are ever growing in relevance to minimize the impacts caused by cement use, notorious for being one of the largest producers (at about 5 to 10%) of global greenhouse gas emissions . The use of alternative materials also is capable of lowering costs, improving concrete properties, and recycling wastes, the latest being relevant for circular economy aspects of

3600-478: The mixed concrete, often to a concrete mixer truck. Modern concrete is usually prepared as a viscous fluid, so that it may be poured into forms. The forms are containers that define the desired shape. Concrete formwork can be prepared in several ways, such as slip forming and steel plate construction . Alternatively, concrete can be mixed into dryer, non-fluid forms and used in factory settings to manufacture precast concrete products. Interruption in pouring

3675-441: The mixing of cement and water into a paste before combining these materials with aggregates can increase the compressive strength of the resulting concrete. The paste is generally mixed in a high-speed , shear-type mixer at a w/c (water to cement ratio) of 0.30 to 0.45 by mass. The cement paste premix may include admixtures such as accelerators or retarders, superplasticizers , pigments , or silica fume . The premixed paste

3750-441: The mixture to improve the physical properties of the wet mix, delay or accelerate the curing time, or otherwise change the finished material. Most concrete is poured with reinforcing materials (such as steel rebar ) embedded to provide tensile strength , yielding reinforced concrete . In the past, lime -based cement binders, such as lime putty, were often used but sometimes with other hydraulic cements , (water resistant) such as

3825-608: The name of the land patented to Colonel Joseph Belt from Charles Calvert, 5th Baron Baltimore , on July 10, 1725. It has historic associations with a 1388 chevauchée , a French word describing a border raid, fought by Lord Percy of England and Earl Douglas of Scotland over hunting grounds, or a " chace ", in the Cheviot Hills of Northumberland and Otterburn . The battle was memorialized in " The Ballad of Chevy Chase ". The area known as Chevy Chase includes several entities in southern Montgomery County : It also includes

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3900-645: The neighborhood of Chevy Chase in northwest Washington, D.C. The United States Postal Service also uses "Chevy Chase" for some postal addresses that lie outside these areas: the town of Somerset , the Village of Friendship Heights , and the part of the Rock Creek Forest neighborhood that lies east of Jones Mill Road and Beach Drive and west of Grubb Road. In the 1880s, Senator Francis G. Newlands of Nevada and his partners began acquiring farmland in unincorporated areas of Maryland and just inside

3975-428: The parkway to Bradley with a spur following Willett Branch to Hillandale Road and that road to a different point on Bradley, but the entire trail was never built. Instead the 3.5 miles (5.6 km) Little Falls hiker-biker paved trail is on road on the Little Falls Parkway between Massachusetts and Dorset. North of Dorset it follows Willett Branch north to Hillandale and east to Norwood Drive. In Little Falls Stream Valley

4050-506: The properties or increase the performance envelope of the mix. Design-mix concrete can have very broad specifications that cannot be met with more basic nominal mixes, but the involvement of the engineer often increases the cost of the concrete mix. Concrete mixes are primarily divided into nominal mix, standard mix and design mix. Nominal mix ratios are given in volume of Cement : Sand : Aggregate {\displaystyle {\text{Cement : Sand : Aggregate}}} . Nominal mixes are

4125-469: The property in 1951, turning it into the group's Youth Conference Center. For decades, the center hosted the National 4-H Conference, an event for 4-Hers throughout the nation to attend, and the annual National Science Bowl in late April or early May. The National 4-H Club Foundation sold the center in 2021 for $ 40 million; as of 2022, it is to be replaced by a senior living development. Chevy Chase

4200-468: The quality and nature of the product. Design mix ratios are decided by an engineer after analyzing the properties of the specific ingredients being used. Instead of using a 'nominal mix' of 1 part cement, 2 parts sand, and 4 parts aggregate (the second example from above), a civil engineer will custom-design a concrete mix to exactly meet the requirements of the site and conditions, setting material ratios and often designing an admixture package to fine-tune

4275-456: The residential neighborhoods. Leon E. Dessez was Chevy Chase's first resident. He and Lindley Johnson of Philadelphia designed the first four houses in the area. Toward the northern end of its holdings, the Land Company dammed Coquelin Run , a stream that crossed its land, to create the manmade Chevy Chase Lake . The body of water furnished water to the coal-fired generators that powered

4350-595: The sale or rental of homes to "a Negro or one of the African race." Others prohibited sales or rentals to "any persons of the Semetic [ sic ] race"—i.e., Jews . By World War II, such restrictive language had largely disappeared from real estate transactions, and all were voided by the 1948 Supreme Court decision in Shelley v. Kraemer . In 1964, Arthur Krock wrote an article for The New York Times alleging that

4425-514: The southern section became Little Falls Stream Valley Park. In 1978, the National Capital Planning Commission approved a trail to run the length of the park, along with a replacement sewer line to be built south of Massachusetts Avenue. This action prompted neighbors to go to court to attempt to stop construction of the trail. Later that year the southern part of the trail and the sewer project were approved by

4500-423: The streetcars of the Land Company's Rock Creek Railway . The streetcar soon became vital to the community; it connected workers to the city, and even ran errands for residents. The lake was also the centerpiece of the Land Company's Chevy Chase Lake trolley park , a venue for boating, swimming, and other activities meant to draw city dwellers to the new suburb. Similar considerations led the Land Company to build

4575-411: The strength of the concrete bonding to resist tension. The long-term durability of Roman concrete structures has been found to be due to its use of pyroclastic (volcanic) rock and ash, whereby the crystallization of strätlingite (a specific and complex calcium aluminosilicate hydrate) and the coalescence of this and similar calcium–aluminium-silicate–hydrate cementing binders helped give the concrete

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4650-497: The surface of concrete for a decorative "exposed aggregate" finish, popular among landscape designers. Admixtures are materials in the form of powder or fluids that are added to the concrete to give it certain characteristics not obtainable with plain concrete mixes. Admixtures are defined as additions "made as the concrete mix is being prepared". The most common admixtures are retarders and accelerators. In normal use, admixture dosages are less than 5% by mass of cement and are added to

4725-535: The surfaces of the aggregate together, and is typically the most expensive component. Thus, variation in sizes of the aggregate reduces the cost of concrete. The aggregate is nearly always stronger than the binder, so its use does not negatively affect the strength of the concrete. Redistribution of aggregates after compaction often creates non-homogeneity due to the influence of vibration. This can lead to strength gradients. Decorative stones such as quartzite , small river stones or crushed glass are sometimes added to

4800-508: The trail is next to the Capital Crescent Trail . Though opponents of the bike trail were concerned the trail would bring crime to the neighborhood, a later review showed that crime dropped after the trail was opened. Today Little Falls Branch flows through a highly urbanized area, and parts of the stream have been altered through construction of underground pipes, culverts and open concrete channels. The stream runs near

4875-655: The various ingredients used to produce a given quantity of concrete, the cement is the most energetically expensive. Even complex and efficient kilns require 3.3 to 3.6 gigajoules of energy to produce a ton of clinker and then grind it into cement . Many kilns can be fueled with difficult-to-dispose-of wastes, the most common being used tires. The extremely high temperatures and long periods of time at those temperatures allows cement kilns to efficiently and completely burn even difficult-to-use fuels. The five major compounds of calcium silicates and aluminates comprising Portland cement range from 5 to 50% in weight. Combining water with

4950-439: The water content or adding chemical admixtures increases concrete workability. Excessive water leads to increased bleeding or segregation of aggregates (when the cement and aggregates start to separate), with the resulting concrete having reduced quality. Changes in gradation can also affect workability of the concrete, although a wide range of gradation can be used for various applications. An undesirable gradation can mean using

5025-527: The water through a process called concrete hydration that hardens it over several hours to form a hard matrix that binds the materials together into a durable stone-like material that has many uses. This time allows concrete to not only be cast in forms, but also to have a variety of tooled processes performed. The hydration process is exothermic , which means ambient temperature plays a significant role in how long it takes concrete to set. Often, additives (such as pozzolans or superplasticizers ) are included in

5100-524: Was Smeaton's Tower , built by British engineer John Smeaton in Devon , England, between 1756 and 1759. This third Eddystone Lighthouse pioneered the use of hydraulic lime in concrete, using pebbles and powdered brick as aggregate. A method for producing Portland cement was developed in England and patented by Joseph Aspdin in 1824. Aspdin chose the name for its similarity to Portland stone , which

5175-626: Was built largely of concrete, and the Pantheon has the world's largest unreinforced concrete dome. Concrete, as the Romans knew it, was a new and revolutionary material. Laid in the shape of arches , vaults and domes , it quickly hardened into a rigid mass, free from many of the internal thrusts and strains that troubled the builders of similar structures in stone or brick. Modern tests show that opus caementicium had as much compressive strength as modern Portland-cement concrete (c. 200 kg/cm  [20 MPa; 2,800 psi]). However, due to

5250-492: Was derived from the Loughborough Mill, which was built and operated alongside the stream in the 19th century. In the mid-19th century, the stream served as an interim water source for Washington, D.C. The Dalecarlia Reservoir was built on the Washington, D.C.–Maryland border next to Little Falls Branchin 1858 and a dam was built on the stream with water diverted into the reservoir starting in 1859. In 1864, with

5325-602: Was greatly reduced. Low kiln temperatures in the burning of lime, lack of pozzolana, and poor mixing all contributed to a decline in the quality of concrete and mortar. From the 11th century, the increased use of stone in church and castle construction led to an increased demand for mortar. Quality began to improve in the 12th century through better grinding and sieving. Medieval lime mortars and concretes were non-hydraulic and were used for binding masonry, "hearting" (binding rubble masonry cores) and foundations. Bartholomaeus Anglicus in his De proprietatibus rerum (1240) describes

5400-452: Was made from quicklime , pozzolana and an aggregate of pumice . Its widespread use in many Roman structures , a key event in the history of architecture termed the Roman architectural revolution , freed Roman construction from the restrictions of stone and brick materials. It enabled revolutionary new designs in terms of both structural complexity and dimension. The Colosseum in Rome

5475-498: Was pioneered by the Nabatean traders who occupied and controlled a series of oases and developed a small empire in the regions of southern Syria and northern Jordan from the 4th century BC. They discovered the advantages of hydraulic lime , with some self-cementing properties, by 700 BC. They built kilns to supply mortar for the construction of rubble masonry houses, concrete floors, and underground waterproof cisterns . They kept

5550-622: Was quarried on the Isle of Portland in Dorset , England. His son William continued developments into the 1840s, earning him recognition for the development of "modern" Portland cement. Reinforced concrete was invented in 1849 by Joseph Monier . and the first reinforced concrete house was built by François Coignet in 1853. The first concrete reinforced bridge was designed and built by Joseph Monier in 1875. Prestressed concrete and post-tensioned concrete were pioneered by Eugène Freyssinet ,

5625-625: Was used for construction in many ancient structures. Mayan concrete at the ruins of Uxmal (AD 850–925) is referenced in Incidents of Travel in the Yucatán by John L. Stephens . "The roof is flat and had been covered with cement". "The floors were cement, in some places hard, but, by long exposure, broken, and now crumbling under the feet." "But throughout the wall was solid, and consisting of large stones imbedded in mortar, almost as hard as rock." Small-scale production of concrete-like materials

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