74-456: Henry Oloyede Fajemirokun , CON (26 July 1926 – 15 February 1978) was a trade unionist who later became a prominent Nigerian industrialist and businessman and one of the country's dynamic indigenous entrepreneurs who had established and built one of the foremost indigenous private sector business concerns in his time. He was a strong believer in, and promoted West Africa 's economic integration alongside Adebayo Adedeji which subsequently led to
148-554: A chemical reaction between the dry ingredients and water. The chemical reaction results in mineral hydrates that are not very water-soluble. This allows setting in wet conditions or under water and further protects the hardened material from chemical attack. The chemical process for hydraulic cement was found by ancient Romans who used volcanic ash ( pozzolana ) with added lime (calcium oxide). Non-hydraulic cement (less common) does not set in wet conditions or under water. Rather, it sets as it dries and reacts with carbon dioxide in
222-546: A mortar made of sand and roughly burnt gypsum (CaSO 4 · 2H 2 O), which is plaster of Paris, which often contained calcium carbonate (CaCO 3 ), Lime (calcium oxide) was used on Crete and by the Ancient Greeks . There is evidence that the Minoans of Crete used crushed potsherds as an artificial pozzolan for hydraulic cement. Nobody knows who first discovered that a combination of hydrated non-hydraulic lime and
296-571: A decade the Henry Stephens Group had managed to successfully build up a solid network trading with firms in foreign countries such as the United Kingdom , United States of America , Poland , Japan , Belgium , Egypt , Germany and Brazil ; and had built up strong relationships and business partnerships, representing or acquiring stakes in foreign owned firms in Nigeria prior to the euphoria of
370-459: A decision to in 1972, an indigenisation decree was promulgated by the Federal government to effect greater indigenous participation in different sectors of the economy. Although a strong proponent of greater indigenous participation, Fajemirokun was also cognizant of the need for continued foreign investment in the country and was vocal on maintaining a balance of both. Barring his failed bid to purchase
444-432: A fine powder. This product, made into a mortar with sand, set in 5–15 minutes. The success of "Roman cement" led other manufacturers to develop rival products by burning artificial hydraulic lime cements of clay and chalk . Roman cement quickly became popular but was largely replaced by Portland cement in the 1850s. Apparently unaware of Smeaton's work, the same principle was identified by Frenchman Louis Vicat in
518-432: A form of hydraulic cement, is by far the most common type of cement in general use around the world. This cement is made by heating limestone (calcium carbonate) with other materials (such as clay ) to 1,450 °C (2,640 °F) in a kiln , in a process known as calcination that liberates a molecule of carbon dioxide from the calcium carbonate to form calcium oxide , or quicklime, which then chemically combines with
592-669: A half-century. Technologies of waste cementation have been developed and deployed at industrial scale in many countries. Cementitious wasteforms require a careful selection and design process adapted to each specific type of waste to satisfy the strict waste acceptance criteria for long-term storage and disposal. Modern development of hydraulic cement began with the start of the Industrial Revolution (around 1800), driven by three main needs: Modern cements are often Portland cement or Portland cement blends, but other cement blends are used in some industrial settings. Portland cement,
666-656: A joint venture with the Anglo-American company Rank Xerox (itself a joint venture between Rank Organisation of the United Kingdom and the Xerox Corporation of the United States of America). Fajemirokun was a co-founder and played a key role in developing and promoting ECOWAS Bank what was to become Ecobank Transnational (ETI), however he passed away before its launch was finalized. As an active investor he became
740-669: A major shareholder in leading companies in Nigeria and abroad. He was denied the opportunity to acquire the Daily Times of Nigeria from the British International Publishing Corporation , ( IPC ) known as the " Daily Mirror Group " who owned the title by the Obasanjo junta . Henry Stephens also was a core investor in Johnson Wax and acquired stakes Fan Milk and two notable construction companies. Fajemirokun
814-787: A market for use in concrete. The use of concrete in construction grew rapidly from 1850 onward, and was soon the dominant use for cements. Thus Portland cement began its predominant role. Isaac Charles Johnson further refined the production of meso-Portland cement (middle stage of development) and claimed he was the real father of Portland cement. Setting time and "early strength" are important characteristics of cements. Hydraulic limes, "natural" cements, and "artificial" cements all rely on their belite (2 CaO · SiO 2 , abbreviated as C 2 S) content for strength development. Belite develops strength slowly. Because they were burned at temperatures below 1,250 °C (2,280 °F), they contained no alite (3 CaO · SiO 2 , abbreviated as C 3 S), which
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#1733093574073888-413: A month for Rosendale cement made it unpopular for constructing highways and bridges, and many states and construction firms turned to Portland cement. Because of the switch to Portland cement, by the end of the 1920s only one of the 15 Rosendale cement companies had survived. But in the early 1930s, builders discovered that, while Portland cement set faster, it was not as durable, especially for highways—to
962-682: A pozzolan produces a hydraulic mixture (see also: Pozzolanic reaction ), but such concrete was used by the Greeks, specifically the Ancient Macedonians , and three centuries later on a large scale by Roman engineers . There is... a kind of powder which from natural causes produces astonishing results. It is found in the neighborhood of Baiae and in the country belonging to the towns round about Mount Vesuvius . This substance when mixed with lime and rubble not only lends strength to buildings of other kinds but even when piers of it are constructed in
1036-515: A significant stake in the Daily Times. Fajemirokun did not participate in taking over any foreign concerns as a result of the indigenisation decrees in 1972 and 1977. Before 1972, he had already pioneered industries and expanded his business interests and was able to form partnerships and joint ventures with foreign firms. Fajemirokun's hard work and masterful timing served him well and enabled him to expand organically into other industries. For more than
1110-579: A trade mission he died in Abidjan , Cote d’Ivoire . Orders, decorations, and medals of Nigeria Nigerian National Honours are a set of orders and decorations conferred upon Nigerians and friends of Nigeria every year. They were instituted by the National Honors Act No. 5 of 1964, during the First Nigerian Republic , to honour Nigerians who have rendered service to the benefit of
1184-726: A very advanced civilisation in El Tajin near Mexico City, in Mexico. A detailed study of the composition of the aggregate and binder show that the aggregate was pumice and the binder was a pozzolanic cement made with volcanic ash and lime. Any preservation of this knowledge in literature from the Middle Ages is unknown, but medieval masons and some military engineers actively used hydraulic cement in structures such as canals , fortresses, harbors , and shipbuilding facilities . A mixture of lime mortar and aggregate with brick or stone facing material
1258-422: Is hydraulic cement , which hardens by hydration of the clinker minerals when water is added. Hydraulic cements (such as Portland cement) are made of a mixture of silicates and oxides, the four main mineral phases of the clinker, abbreviated in the cement chemist notation , being: The silicates are responsible for the cement's mechanical properties — the tricalcium aluminate and brownmillerite are essential for
1332-512: Is pozzolanic , so that ultimate strength is maintained. Because fly ash addition allows a lower concrete water content, early strength can also be maintained. Where good quality cheap fly ash is available, this can be an economic alternative to ordinary Portland cement. Portland pozzolan cement includes fly ash cement, since fly ash is a pozzolan , but also includes cements made from other natural or artificial pozzolans. In countries where volcanic ashes are available (e.g., Italy, Chile, Mexico,
1406-403: Is a binder , a chemical substance used for construction that sets , hardens, and adheres to other materials to bind them together. Cement is seldom used on its own, but rather to bind sand and gravel ( aggregate ) together. Cement mixed with fine aggregate produces mortar for masonry, or with sand and gravel , produces concrete . Concrete is the most widely used material in existence and
1480-520: Is a major emitter of global carbon dioxide emissions . The lime reacts with silicon dioxide to produce dicalcium silicate and tricalcium silicate. The lime also reacts with aluminium oxide to form tricalcium aluminate. In the last step, calcium oxide, aluminium oxide, and ferric oxide react together to form brownmillerite. A less common form of cement is non-hydraulic cement , such as slaked lime ( calcium oxide mixed with water), which hardens by carbonation in contact with carbon dioxide , which
1554-569: Is about 4.4 billion tonnes per year (2021, estimation), of which about half is made in China, followed by India and Vietnam. The cement production process is responsible for nearly 8% (2018) of global CO 2 emissions, which includes heating raw materials in a cement kiln by fuel combustion and release of CO 2 stored in the calcium carbonate (calcination process). Its hydrated products, such as concrete, gradually reabsorb atmospheric CO 2 (carbonation process), compensating for approximately 30% of
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#17330935740731628-424: Is behind only water as the planet's most-consumed resource. Cements used in construction are usually inorganic , often lime - or calcium silicate -based, and are either hydraulic or less commonly non-hydraulic , depending on the ability of the cement to set in the presence of water (see hydraulic and non-hydraulic lime plaster ). Hydraulic cements (e.g., Portland cement ) set and become adhesive through
1702-417: Is completely evaporated (this process is technically called setting ), the carbonation starts: This reaction is slow, because the partial pressure of carbon dioxide in the air is low (~ 0.4 millibar). The carbonation reaction requires that the dry cement be exposed to air, so the slaked lime is a non-hydraulic cement and cannot be used under water. This process is called the lime cycle . Perhaps
1776-555: Is constantly fed into a rotary kiln, it allowed a continuous manufacturing process to replace lower capacity batch production processes. Calcium aluminate cements were patented in 1908 in France by Jules Bied for better resistance to sulfates. Also in 1908, Thomas Edison experimented with pre-cast concrete in houses in Union, N.J. In the US, after World War One, the long curing time of at least
1850-667: Is more usually added to Portland cement at the concrete mixer. Masonry cements are used for preparing bricklaying mortars and stuccos , and must not be used in concrete. They are usually complex proprietary formulations containing Portland clinker and a number of other ingredients that may include limestone, hydrated lime, air entrainers, retarders, waterproofers, and coloring agents. They are formulated to yield workable mortars that allow rapid and consistent masonry work. Subtle variations of masonry cement in North America are plastic cements and stucco cements. These are designed to produce
1924-403: Is present in the air (~ 412 vol. ppm ≃ 0.04 vol. %). First calcium oxide (lime) is produced from calcium carbonate ( limestone or chalk ) by calcination at temperatures above 825 °C (1,517 °F) for about 10 hours at atmospheric pressure : The calcium oxide is then spent (slaked) by mixing it with water to make slaked lime ( calcium hydroxide ): Once the excess water
1998-483: Is responsible for early strength in modern cements. The first cement to consistently contain alite was made by William Aspdin in the early 1840s: This was what we call today "modern" Portland cement. Because of the air of mystery with which William Aspdin surrounded his product, others ( e.g., Vicat and Johnson) have claimed precedence in this invention, but recent analysis of both his concrete and raw cement have shown that William Aspdin's product made at Northfleet , Kent
2072-438: Is to make concrete. Portland cement may be grey or white . Portland cement blends are often available as inter-ground mixtures from cement producers, but similar formulations are often also mixed from the ground components at the concrete mixing plant. Portland blast-furnace slag cement , or blast furnace cement (ASTM C595 and EN 197-1 nomenclature respectively), contains up to 95% ground granulated blast furnace slag , with
2146-474: The Isle of Portland , Dorset, England. However, Aspdins' cement was nothing like modern Portland cement but was a first step in its development, called a proto-Portland cement . Joseph Aspdins' son William Aspdin had left his father's company and in his cement manufacturing apparently accidentally produced calcium silicates in the 1840s, a middle step in the development of Portland cement. William Aspdin's innovation
2220-582: The Royal West African Frontier Force at the age of 18 and served in India during World War II . After the war, he joined the Post and Telegraph Department as a clerk and studied privately for his Cambridge School Certificate. After serving during World War II, he began his career at the Post and Telegraph Department. He was a member of the workers' union in the department and rose to become President of
2294-517: The Art to Prepare a Good Mortar published in St. Petersburg . A few years later in 1825, he published another book, which described various methods of making cement and concrete, and the benefits of cement in the construction of buildings and embankments. Portland cement , the most common type of cement in general use around the world as a basic ingredient of concrete, mortar , stucco , and non-speciality grout ,
Henry Fajemirokun - Misplaced Pages Continue
2368-708: The Chamber of Commerce and industry Movement. He was the 4th President Archived 9 January 2021 at the Wayback Machine of the Nigerian Association of Chambers of Commerce, Industry, Mines and Agriculture (NACCIMA) , The 6th President Archived 22 April 2018 at the Wayback Machine of the Lagos Chamber of Commerce and Industry , the 1st President of the Federation of West African Chambers of Commerce (1972–1978) and
2442-574: The Far East. Fajemirokun also ventured into commodity brokerage and in 1969 he bought and held a seat on the London Stock Exchange . Fajemirokun's company Henry Stephens was a pioneer in Nigerian Oil industry as the first indigenous private oil company to get an offshore exploration license in the country's first ever offshore licensing round of oil prospecting licenses (OPL) in 1970. Bidding
2516-564: The Federal Military Government and foreign firms. The crowding out of the organized private sector by the FMG was vocally criticized because the belief was that the organized private sector was better suited to both manage the relationships with the foreign firms ensuring a longer-term commitment to the country rather than triggering an exodus and to negotiate a fair price for the value of the equity being sold down rather than capitulating to
2590-768: The Honorary Degree of Doctor of Science in Business Administration in recognition of his significant contributions to the academic and business communities. For his contributions to the development of Commerce and Industry in the country, five years after his death in 1983 the Federal Government honoured him with a posthumous national award of the Commander of the Order of the Niger (CON) . On 15 February 1978, whilst leading
2664-526: The New York Commissioner of Highways to construct an experimental section of highway near New Paltz, New York , using one sack of Rosendale to six sacks of Portland cement. It was a success, and for decades the Rosendale-Portland cement blend was used in concrete highway and concrete bridge construction. Cementitious materials have been used as a nuclear waste immobilizing matrix for more than
2738-855: The Nigerian civil war he was active in supporting the Red Cross and led other initiatives to help those in need. He made several donations to educational and community institutions. He gave and donated generously to individuals, communities, the Red Cross Movement, Religious Organizations, Universities, State Development Funds, Students’ Clubs, Youth Organizations and the Southern African Relief Fund to which he personally donated ₦110,000 (One Hundred and Ten Thousand Naira) in January 1977 . Fajemirokun contributions were recognised and in 1968, Fajemirokun
2812-457: The Philippines), these cements are often the most common form in use. The maximum replacement ratios are generally defined as for Portland-fly ash cement. Portland silica fume cement. Addition of silica fume can yield exceptionally high strengths, and cements containing 5–20% silica fume are occasionally produced, with 10% being the maximum allowed addition under EN 197–1. However, silica fume
2886-603: The absence of pozzolanic ash, the Romans used powdered brick or pottery as a substitute and they may have used crushed tiles for this purpose before discovering natural sources near Rome. The huge dome of the Pantheon in Rome and the massive Baths of Caracalla are examples of ancient structures made from these concretes, many of which still stand. The vast system of Roman aqueducts also made extensive use of hydraulic cement. Roman concrete
2960-623: The air. It is resistant to attack by chemicals after setting. The word "cement" can be traced back to the Ancient Roman term opus caementicium , used to describe masonry resembling modern concrete that was made from crushed rock with burnt lime as binder. The volcanic ash and pulverized brick supplements that were added to the burnt lime, to obtain a hydraulic binder , were later referred to as cementum , cimentum , cäment , and cement . In modern times, organic polymers are sometimes used as cements in concrete. World production of cement
3034-460: The available hydraulic limes, visiting their production sites, and noted that the "hydraulicity" of the lime was directly related to the clay content of the limestone used to make it. Smeaton was a civil engineer by profession, and took the idea no further. In the South Atlantic seaboard of the United States, tabby relying on the oyster-shell middens of earlier Native American populations
Henry Fajemirokun - Misplaced Pages Continue
3108-626: The co-founder and founding President of the Nigerian-British Chamber of Commerce Archived 2 November 2017 at the Wayback Machine (NBCC) alongside Sir Adam Thomson , the Chairman of British Caledonian Airways now part of British Airways). He was a member of the Board of Governors of and former President of Nigerian-American Chamber of Commerce (NACC). He was also the vice-president, Federation of Commonwealth Chambers of Commerce . Fajemirokun
3182-415: The contemporary nationalism at the time in form of the indigenisation decrees by the government. The Group was well positioned to expand into other industries and by 1977 was in the process of establishing hotels, truck assembly plants, breweries and other manufacturing concerns including the acquisition and development of mining quarries for cement. Groups such as his served to counter the competition from
3256-539: The demands of the FMG the time. Fajemirokun led the negotiations to establish the first private merchant bank in the country Nigerian-American Merchant Bank Limited (NAMBL) bringing in First Bank of Boston (later Bank of Boston ) alongside other indigenous investors. The bank was setup after his sudden death with the technical assistance and shareholding of Bank of Boston and Boston Overseas Financial Corporation (subsequently merged with Bank of America ). Fajemirokun
3330-414: The department's Ex-Servicemen's Union in 1948. In 1952, he became President of the Post and Telegraph's Clerical and Workers Allied Union. Fajemirokun started private business in 1955 from a loan he received from a maternal relative. He entered the agricultural export sector, exporting cattle bones first then hides and skin, cocoa, rubber , coffee and shea nuts and imported primarily cement. He earned
3404-420: The development of new cements. Most famous was Parker's " Roman cement ". This was developed by James Parker in the 1780s, and finally patented in 1796. It was, in fact, nothing like material used by the Romans, but was a "natural cement" made by burning septaria – nodules that are found in certain clay deposits, and that contain both clay minerals and calcium carbonate . The burnt nodules were ground to
3478-607: The earliest known occurrence of cement is from twelve million years ago. A deposit of cement was formed after an occurrence of oil shale located adjacent to a bed of limestone burned by natural causes. These ancient deposits were investigated in the 1960s and 1970s. Cement, chemically speaking, is a product that includes lime as the primary binding ingredient, but is far from the first material used for cementation. The Babylonians and Assyrians used bitumen (asphalt or pitch ) to bind together burnt brick or alabaster slabs. In Ancient Egypt , stone blocks were cemented together with
3552-461: The first decade of the nineteenth century. Vicat went on to devise a method of combining chalk and clay into an intimate mixture, and, burning this, produced an "artificial cement" in 1817 considered the "principal forerunner" of Portland cement and "...Edgar Dobbs of Southwark patented a cement of this kind in 1811." In Russia, Egor Cheliev created a new binder by mixing lime and clay. His results were published in 1822 in his book A Treatise on
3626-521: The formation of the Economic Community of West African States ( ECOWAS ). Fajemirokun saw the need for a well-organised private sector and was devoted to developing and strengthening the private sector, he expended considerable resources to advance the activities of the Chamber of Commerce and Industry Movement within Nigeria, West Africa and the Commonwealth. Fajemirokun held various positions in
3700-402: The formation of the liquid phase during the sintering ( firing ) process of clinker at high temperature in the kiln . The chemistry of these reactions is not completely clear and is still the object of research. First, the limestone (calcium carbonate) is burned to remove its carbon, producing lime (calcium oxide) in what is known as a calcination reaction. This single chemical reaction
3774-464: The founder, chairman and largest shareholder of the Henry Stephens Group of companies, under his direction the company grew rapidly and diversified into several spheres such as cement and building materials, engineering, banking, insurance, shipping, ship broking and oil prospecting. He was a leading voice in industry and championed greater participation by Nigerians in the economy which was still dominated by foreign concerns primarily in industry. Following
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#17330935740733848-426: The initial CO 2 emissions. Cement materials can be classified into two distinct categories: hydraulic cements and non-hydraulic cements according to their respective setting and hardening mechanisms. Hydraulic cement setting and hardening involves hydration reactions and therefore requires water, while non-hydraulic cements only react with a gas and can directly set under air. By far the most common type of cement
3922-404: The low pH (8.5–9.5) of its pore water) limited its use as reinforced concrete for building construction. The next development in the manufacture of Portland cement was the introduction of the rotary kiln . It produced a clinker mixture that was both stronger, because more alite (C 3 S) is formed at the higher temperature it achieved (1450 °C), and more homogeneous. Because raw material
3996-458: The nation. These honours are distinct from the honours that are part of the country's ancient chieftaincy system , which is a separate (but also legally defined) entity. National Honours are the highest honours or awards that a citizen can receive from his or her country for service to the country. The Nigerian National Honours, in descending order of importance, are: The GCFR and GCON are customarily respectively bestowed on former occupants of
4070-676: The office of President of Nigeria and Vice President of Nigeria including former military heads of state of Nigeria and Chiefs of General Staff. The GCON is also customarily bestowed on the Chief Justice of Nigeria and the President of the Nigerian Senate during their first year in office, while the CON is customarily bestowed on Justices of the Supreme Court of Nigeria Cement A cement
4144-426: The open area. The remaining blocks said to be the most prospective, were reserved for the proposed national oil company Nigerian National Oil Corporation (NNOC) which was established officially in 1972 .Other winners of the licensing round were Deminex a German Consortium, Occidental Petroleum , Japan Petroleum Company and Monsanto . The Group acquired the sole distributorship for Rank Xerox (now Xerox ), forming
4218-465: The other materials in the mix to form calcium silicates and other cementitious compounds. The resulting hard substance, called 'clinker', is then ground with a small amount of gypsum ( CaSO 4 ·2H 2 O ) into a powder to make ordinary Portland cement , the most commonly used type of cement (often referred to as OPC). Portland cement is a basic ingredient of concrete , mortar , and most non-specialty grout . The most common use for Portland cement
4292-467: The point that some states stopped building highways and roads with cement. Bertrain H. Wait, an engineer whose company had helped construct the New York City's Catskill Aqueduct , was impressed with the durability of Rosendale cement, and came up with a blend of both Rosendale and Portland cements that had the good attributes of both. It was highly durable and had a much faster setting time. Wait convinced
4366-447: The rest Portland clinker and a little gypsum. All compositions produce high ultimate strength, but as slag content is increased, early strength is reduced, while sulfate resistance increases and heat evolution diminishes. Used as an economic alternative to Portland sulfate-resisting and low-heat cements. Portland-fly ash cement contains up to 40% fly ash under ASTM standards (ASTM C595), or 35% under EN standards (EN 197–1). The fly ash
4440-407: The sea, they set hard underwater. The Greeks used volcanic tuff from the island of Thera as their pozzolan and the Romans used crushed volcanic ash (activated aluminium silicates ) with lime. This mixture could set under water, increasing its resistance to corrosion like rust. The material was called pozzolana from the town of Pozzuoli , west of Naples where volcanic ash was extracted. In
4514-452: The trust of buyers who extended letters of credit to finance his business. He added other ventures into his business activities, in 1962, he started a maritime services firm. By 1960 he had become one of the largest importers of cement from Egypt and Poland . He received funding for this particular venture from a credit facility that had been provided to him by a British bank in London . As
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#17330935740734588-652: Was a pioneer in the Nigerian maritime industry and was the first indigenous company to own an interest in a shipping line. He established Henry Stephens Shipping Company and the Nigeria Shipping Company with two lines: Nigeria-Far East Line and the Nigeria-South America Line and acquired three drybulk ships. The Nigeria- South America Line provided liner services between Brazil and the Nigerian Far East Line provided liner services to Japan and
4662-444: Was a true alite-based cement. However, Aspdin's methods were "rule-of-thumb": Vicat is responsible for establishing the chemical basis of these cements, and Johnson established the importance of sintering the mix in the kiln . In the US the first large-scale use of cement was Rosendale cement , a natural cement mined from a massive deposit of dolomite discovered in the early 19th century near Rosendale, New York . Rosendale cement
4736-514: Was also a director of First Bank Nigeria Limited, director Nigeria Krafts Bags Limited, non-executive director Nigerian Diversified Investments, director Nigeria Sewing Machine Manufacturing Company Limited. He was Chairman of the Lagos State Tourism Advisory Committee. Fajemirokun was an active philanthropist in the community and church, giving to charitable causes both in Nigeria and abroad, particularly South Africa. During
4810-710: Was awarded the chieftaincy title of Yegbata of Ile-Oluji by his traditional sovereign , the Jegun, thus making him a tribal aristocrat of the Yoruba people . He was later made the Asiwaju of Oke-Igbo (1971), the Lijoka of Ondo (1973), the Orunta of Ifewara (1974) and the Obaloro of Ado Ekiti (1977). In 1972, The University of Ife (now Obafemi Awolowo University , Ife) also conferred on him
4884-697: Was born in Ile Oluji , Ondo State to the family of Daniel Famakinwa Fajemirokun and Felicia Adebumi Fajemirokun (née Akinsuroju) (b.1891), daughter of High Chief Odofin Oganbule Akinsuroju and Madam Adesemi Akinsuroju, and granddaughter of Omoba Adebamigbei (whose father was the Jegun of Ile Oluji). Fajemirokun was educated at St.Peter's School, Ile-Oluji and then at St Luke's School, Oke-igbo for his primary education. For his secondary education, he educated at CMS Grammar School, Lagos and then at Ondo Boys High School (1942–1944). After Ondo Boys school, he joined
4958-479: Was counterintuitive for manufacturers of "artificial cements", because they required more lime in the mix (a problem for his father), a much higher kiln temperature (and therefore more fuel), and the resulting clinker was very hard and rapidly wore down the millstones , which were the only available grinding technology of the time. Manufacturing costs were therefore considerably higher, but the product set reasonably slowly and developed strength quickly, thus opening up
5032-468: Was developed in England in the mid 19th century, and usually originates from limestone . James Frost produced what he called "British cement" in a similar manner around the same time, but did not obtain a patent until 1822. In 1824, Joseph Aspdin patented a similar material, which he called Portland cement , because the render made from it was in color similar to the prestigious Portland stone quarried on
5106-494: Was extremely popular for the foundation of buildings ( e.g. , Statue of Liberty , Capitol Building , Brooklyn Bridge ) and lining water pipes. Sorel cement , or magnesia-based cement, was patented in 1867 by the Frenchman Stanislas Sorel . It was stronger than Portland cement but its poor water resistance (leaching) and corrosive properties ( pitting corrosion due to the presence of leachable chloride anions and
5180-622: Was formalized by French and British engineers in the 18th century. John Smeaton made an important contribution to the development of cements while planning the construction of the third Eddystone Lighthouse (1755–59) in the English Channel now known as Smeaton's Tower . He needed a hydraulic mortar that would set and develop some strength in the twelve-hour period between successive high tides . He performed experiments with combinations of different limestones and additives including trass and pozzolanas and did exhaustive market research on
5254-495: Was opened between 26 February and 18 March on about 7000 square miles of the continental shelf. Twenty seven blocks were offered composed of areas relinquished according to leasing regulations 30 November 1968 plus additional deeper water acreage up to the 200 fathom line on the outer shelf. A total of 106 bids from over 30 oil companies or groups were made for these continental shelf OPLs. In July, Newcomers to Nigeria were offered blocks. Only 15 blocks were offered covering only half of
5328-405: Was rarely used on the outside of buildings. The normal technique was to use brick facing material as the formwork for an infill of mortar mixed with an aggregate of broken pieces of stone, brick, potsherds , recycled chunks of concrete, or other building rubble. Lightweight concrete was designed and used for the construction of structural elements by the pre-Columbian builders who lived in
5402-407: Was used in house construction from the 1730s to the 1860s. In Britain particularly, good quality building stone became ever more expensive during a period of rapid growth, and it became a common practice to construct prestige buildings from the new industrial bricks, and to finish them with a stucco to imitate stone. Hydraulic limes were favored for this, but the need for a fast set time encouraged
5476-720: Was used in the Eastern Roman Empire as well as in the West into the Gothic period . The German Rhineland continued to use hydraulic mortar throughout the Middle Ages, having local pozzolana deposits called trass . Tabby is a building material made from oyster shell lime, sand, and whole oyster shells to form a concrete. The Spanish introduced it to the Americas in the sixteenth century. The technical knowledge for making hydraulic cement
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