THOSE WHO MADE THE HISTORY OF CEMENT AND CONCRETE- PART THREE

Robert Maillart was a Swiss civil engineer who revolutionized the use of structural reinforced concrete with designs of structural art. His radical use of reinforced concrete revolutionized masonry arch bridge design. In 1901 he built his first bridge over the Inn River at Zuoz. For this he designed a curved arch and a flat roadway connected by longitudinal walls that turned the complete structure into a hollow-box girder. This was the first concrete hollow-box to be constructed. Maillart built many other structures including a number of factories and warehouses in Russia between 1912 and 1919. The Russian Revolution temporarily ruined his financially, but he returned to Switzerland to resume his career. Mushroom ceilings and flared bottom columns are his famous designs.

Auguste Perret was a French architect notable for his pioneering contributions to architectural use of reinforced concrete. Auguste studied architecture, but left before receiving his diploma and joined with his father’s business. His father was a stonemason. Auguste was the first to dare to use concrete, until then the it was only the domain of engineers. He used reinforced concrete, which he decorated coloured, treated with several techniques such as bush-hammering, chipping, polishing or washing. He had different types of components and different proportions. With his bothers, he built the first apartment block in 1903 with reinforced concrete. He used thin shell roof vaulting for his warehouses in Casablanca (1915) and elegant concrete arches for a clothing factory in Paris (1919).

Edwin Clarence Eckel was an American engineer and geologist born in New York, US. He was graduated from New York University in 1896. He started his career as assistant geologist of New York in 1900, later in 1902 he joined in US Geological Survey as assistant geologist. In 1906 he became the geologist in charge section of iron ore and structural materials. In 1907, Eckel joined President Dominion Cement Company as construction engineering and geologist.

Edwin Clarence Eckel’s major significant contribution goes to the “Eckel’s rule” (called the cementation index), which is really a modification of Newberry’s rule for proportioning the raw materials. His published works include “Cements, Limes and Plasters” (1905), “The materials and Manufacture of Portland Cement”

Gebhardt Jaeger was a Columbus industrialist and inventor of the concrete mixer. He was born and educated in Germany and at the age of eighteen years emigrated to US and settled at St. Louis, Missouri. In 1900, Jaeger joined in the Union Steel Company (Pittsburgh, Pennsylvania) as a designer of woven wire fence machines. Mr. Jaeger came to Columbus from Pittsburgh in 1902 and shortly after designed the well-known Hayden Concrete Block Machine. In 1905 he designed and built the first concrete mixing machine, which was later manufactured by his own company with such unequalled success. In 1928 Mr. Jaeger got the idea of a truck mixer and later the company acquired ownership of the oldest and most basic patents on truck mixers. This truck mixers load carefully weighed and proportioned amounts of sand, stone and cement under convenient bins and mix the concrete while in transit to the job, where it is to be used. 

Carl Akeley was an American taxidermist (preserving of animal’s body via mounting over an armature or stuffing), sculptor, biologist, inventor and nature photographer. In 1888, he took a job at the Milwaukee Public Museum and worked there for about 7 years, but failed to find the freedom to try out his own ideas that he was seeking. So, in 1895, he was happy to accept a job offer from the Field Columbian Museum in Chicago. Carl Akeley invented new method to repair the crumbling fa?ade of the museum. He is credited with the invention of “spraying concrete and mortar onto the surface at high velocity in 1907. He used the method of blowing dry material out of a hose with compressed air, injecting water at the nozzle as it was released. In 1911, Carl Akeley was granted patent for his inventions, the “cement gun”, the equipment used and “gunite”, the material used. The machine and the process were introduced at the Cement Show, in Madison Square, New York.

American Railway Engineers used the term “shotcrete” to describe the same process done with cement gun but with coarse aggregate mixture. In pool construction, “shotcrete” refers to wet mix and “Gunite” refers to dry mix. In fact, Gunite was the original term coined by Akeley, trademarked in 1909 and patented in North Carolina. The concrete mixture is by pneumatic pressure from a gun, hence "gun"-ite. The term "Gunite" became the registered trademark of Allentown Equipment, the oldest manufacturer of gunite equipment. Other manufacturers were thus compelled to use other terminology to describe the process such as shotcrete, pneumatic concrete, guncrete, etc.

Thomas A. Edison was an American inventor and businessman born in Milan, Ohio. He has over 1000 patents in his name like the phonograph, light bulb, and the motion picture. In 1899, Thomas Alva Edison founded a concrete company that produced high quality Portland cement. Edison made significant improvements to the production process of cement. His cement company (Edison Portland Cement Company) featured the first long, rotating kilns in the world. During that time, the standard length of kiln was between 60 and 80 feet, whereas Edison's kilns were up to 150 feet. Drunk with ambition, Edison looked for ways to utilize concrete to produce full objects like refrigerators, pianos, and particularly, the entire house. In the 1910s he successfully cast house prototypes by pouring concrete in a single shot. Edison was the first to investigate the use of formwork molds that could repeatedly be used to create concrete houses.

Fairfax Harrison was an American lawyer, businessman and writer. He started his career as a lawyer for the Southern Railway Company in 1896. Later in 1906 he became vice-president of finance and in 1913 he was elected president of Southern Railway Company. Harrison was an author as well as an industrialist. Among his works was a translation of the agricultural works of ancient Roman writer Marcus Porcius Cato, “On Agriculture” (1913).

Stephen Stepanian was an Armenian-American inventor and a Columbus industrialist. Stephen was born in Armenia and in 1906 moved to Ohio, US. He was credited with the ownership of numerous patents, but most significant one was the self-discharging motorized transit mixer that was the predecessor of the concrete mixer truck. Stephen is often called as the “father of the ready-mix concrete industry”. Stephen invented a self-discharging motorized transit mixer that was the predecessor of the concrete mixer truck and applied for a patent in 1916. However, the patent was rejected in April 1917 by the patent office because it was believed that a truck could not support the weight of a concrete mixer on top of it. The patent office also noted that there was no previous patenting information that proves integration was possible with both the mixer and the design of the truck. Other sources suggest that the patent was rejected because Stepanian was not an American citizen. However, on December 21, 1928, Stepanian reapplied for the patent and received approval on November 21, 1933 (Patent No. 1,935,922- Concrete mixing and transporting vehicle).

Duff A. Abrams was an American researcher in the field of concrete technology. Duff Abrams published data that showed that for a given set of concreting materials, the strength of the concrete depends solely on the relative quantity of water compared with the cement. In other words, the strength is a function of the water to cement ratio (w/c) where w represents the mass of water and c represents the mass of cement. This became known as Abrams law and it remains valid today as it was in 1918.

His other contributions on concrete are:

1.               The definition of concept of fineness modulus (FM)

2.               A test method for workability of concrete by using Abram's Cone (Slump Cone)

3.               The concept of water-cement ratio.

Abrams established the relationship between the water-cement ratio and the compressive strength of concrete. The results were first published in 1918 in D. A. Abrams, Design of Concrete Mixtures, Bulletin 1, Structural Materials Research Laboratory, Lewis Institute, Chicago, 1918. The law states that the strength of a concrete mix is inversely related to the mass ratio of water to cement. As the water content increases, the strength of concrete decreases.

Stephen J. Hayde is known as “Father of Light Weight Concrete Industry”. He was an American born son of Irish immigrants from Tipparary. Hayde was a contractor and brick maker. His inventive and resourceful mind was continuously searching for a solution for abnormal bloating of some of the brick as shale expanded when subjected to high temperature during burning processes. It came to his mind that such discarded bloated bricks can be crushed and screened into suitable sizes, and can be used as light weight aggregate. The story of expanded shale as light weight concrete aggregate was beginning there. During the World War I, due to the shortage of high-grade plate steel for building ships, authorities were searching for materials other than steel. Reinforced concrete was in use for ship building in Scandinavian countries, but dead weight was a serious concern. Researchers learned of Hayde’s work and undertook further experimentation which confirmed his findings. On February 18, 1918, Hayde was granted patent on his process (US Patent No. 1,255,878).

Eugene Freyssinet was a French structural and civil engineer and pioneer in the use of reinforced- concrete construction. In 1921, he built two gigantic parabolic-arched airship hangars at Orly Airport in Paris. In 1928, he was granted a patent for pre-stressed concrete. He realized that concrete slowly deform under load over time. He also recognized that this deformation is permanent, and when loads were taken off the structure it did not go back to its original position. Freyssinet later realized that he had just discovered the phenomenon of creep in concrete structures.

Johan Axel Eriksson was a Swedish architect and inventor. While he was working as Assistant Professor under Professor Henrik Hreuger (1923) on the thermal insulation of building materials, Eriksson experimented by mixing calcined shale, cement and aluminium powder, then exposing this mixture to high temperature and pressure in an autoclave. The result was a light porous but compact material with good insulating qualities. The discovery was almost accidental. Dr. Eriksson patented his “gas concrete” (Foam Concrete) known locally as “poren betong” in 1924.

Max Giese was a German engineer and inventor of concrete pump along with Fritz Hull. The first pumping was on the construction site of the Deutsches Haus in Flensburg and the Marine cenotaph. They noticed that larger size particles did not pass through the ball valves and caused gear breakage. Yet despite this failure, they pumped concrete to a height of 27 meters (some report says 38 meters) and a distance of 120 meters at a delivery rate of 10 m3/h. Max Giese was also the founder of Max Bau GmbH, which developed into a major construction company. He had been granted patent for “Method of conveying concrete on buildings” (No. 553,060 in 1927) and “Concrete mortar pump with piston flushing” (No. 485, 470 in 1928). In Holland, on 16 December 1931, Mr Jacobus Cornelius Kooijman (Jacobus C. Kooyman) was granted patent no. 26113 for a concrete pump (published on 15 February 1932). When the patents were published, both parties had already produced and marketed concrete pumps. In view of the similarities of the inventions, an agreement was already passed in June 1932 on the joint use of the patents of Giese / Hell and Kooijman. After the company founder in 2003, the Max-Giese-Stra?e was named in the district Schreventeich . At the end of the same year, Max Giese Bau GmbH filed for bankruptcy.

R. H. Bogue was an American chemist and physicist. He graduated from Tufts University in 1912, Massachusetts College (1915), and the University of Pittsburgh (PhD in Philosophy, 1920), and he had acquired professional experience as an Adjunct Professor at Montana State College (1915-1917), an adjunct to the Mellon Institute (1917-1922), and Associate Professor at Lafayette College of Easton (1922-1924). In 1924, he took office as the Director of Portland Cement Association (PCA) Fellowship. Among Bogue's personal contributions is the "Compound Calculation in Portland Cement", published in 1929. Until the publication of this paper, there was much controversy about the compositions of compounds present in clinker and cement. The Bogue calculation is used to calculate the approximate proportions of the four main minerals in Portland cement clinker. The standard Bogue calculation refers to cement clinker, rather than cement, but it can be adjusted for use with cement. Although the result is only approximate, the calculation is an extremely useful and widely-used calculation in the cement industry. The calculation assumes that the four main clinker minerals are pure minerals with compositions:

Alite: C3S, or tricalcium silicate

Belite: C2S, or dicalcium silicate

Celiet (Aluminate phase): C3A, or tricalcium aluminate

Ferrite: C4AF, or tetracalcium aluminoferrite

It is important to remember that these assumed compositions are only approximations to the actual compositions of the minerals.

Eduardo Torroja was a Spanish structural engineer and a pioneer in the design of concrete shell structures. After completing his studies in civil engineering, Eduardo Torroja began working in the Compa?ía de Construcciones Hidráulicas y Civiles (Civil and Hydraulic Construction Company), headed by Jose Eugenio Ribera, who pioneered the use of reinforced concrete in Spain. He made his name with the concrete shell-roof at Algeciras Market hall (1933) and the cantilevered grandstand roofs in the form of giant flutes at the Zarzuela Racecourse (1935). His writings include “The Philosophy of Structures” (1951, 1958) and “The structures of Eduardo Torroja (1958).

Dr. F.M. Lea was educated at King Edward VI School, Birmingham, and after war service during 1918-1919, he entered the University of Birmingham, where he gained the Frankland Prize for practical chemistry and granted B. Sc. with first class honours in 1921. He completed his M. Sc. in 1922 and D. Sc. in 1935. He was elected as an associate of the Institute of Chemistry in 1922 and fellow in 1936. Dr. Lea is well recognized of his researches on the constitution of silicate systems and the chemistry of cement in its physic-chemical aspects. Dr. Lea published his most famous book “The Chemistry of Cement and Concrete” in 1935. He served on a number of scientific committees and organizations.

Frank Wright was an American architect, writer and educator. He believed that structure and space could create and convey cultural values and this belief led him to create entirely new types of architecture. Until the arrival of Frank Wright, concrete buildings were built in the same style as more conventional structures. Wright was the first architect, since Roman times to realize that reinforced concrete allowed the creation of completely new forms. He used the extra ordinary tensile strength of the material to create cantilevered structures. He had a period of notoriety and isolation in his life. When he returned to design after this period, he produced some of his most notable structures including Falling Waters (1937) and Guggenheim Museum (1959).

Raymond E. Davis was born in Gorham, Maine, north-eastern United States and was a professor of civil engineering and director of the Materials Testing Laboratory at the University of California at Berkeley from 1920 until his retirement in 1952. He an authority on engineering materials, whose research helped in the construction of the Golden Gate and San Francisco‐Oak land Bay Bridges as well as the Hoover and Grand Coulee Dams. His interests in civil engineering projects were deep rooted at an early age so that even before completing his basic engineering education he spent several years in the field as a topographer and engineering inspector. Returning to the University of Maine, he received his B.S. in 1911 and C.E. in 1914. During 1911 through 1917 he became interested in teaching and served as Instructor and Associate in Civil Engineering at the University of Illinois, where he received his M.S. in 1916. This activity was interrupted by World War I, during which he was a first lieutenant, Engineering Corps, serving as Assistant to the Department Engineer, Western Department, in charge of collecting and compiling data for the War Department. When the war ended he resumed his career in teaching, serving for the next two years as Associate Professor of Civil Engineering at the University of Nebraska. His first association with the University of California began in 1920, where his keen interest in the properties of engineering materials soon resulted in his appointment as Director of the then small Engineering Materials Laboratory, and as Professor of Civil Engineering.

Among the many studies on concrete which he pioneered and for which he won acclaim are (a) volume changes and creep, or plastic flow of concrete under sustained loads; and (b) the use of pozzolans as a partial replacement of part of the cement in concrete mixes. The first comprehensive data on the use of fly ash in concrete in North America were reported by Davis et al. In 1937, Davis along with R. W. Carlson, Joe W. Kelly and Harmer E. Davis published the paper titled “Properties of Cements and Concrete Containing Fly Ash”. The researches had established that fly ash possesses pozzolanic property similar to volcanic ash and deserves to be utilized in lime/cement concrete works.

Brad Bowman is known as the "father of stamped concrete" and founder of the Bomanite Company. During the 1950s, Bowman installed exposed aggregate concrete walls and slabs, and began experimenting with ways to add patterns to his work with a technique he called "ornamented concrete". The original cast-in-place, colored, textured and imprinted architectural concrete paving known as the Bomanite process, was born. Brad Bowman started experimenting using the most basic methods to put a pattern into flat concrete walls and slabs. He started with single wooden print patterns that crudely replicated a brick, and then built platform stamps that imprinted several patterns of a brick at the same time. His first stamps were made of wood, then sheet metal, then aluminium moulds. He quickly recognised the potential this presented and having patented the process, in 1970 he set up a franchise network across the USA. 

Gustave Magnel was a Belgian engineer and professor at Ghent University. He is known for his expertise regarding reinforced concrete and prestressed concrete. The first major bridge made of prestressed concrete in the United States, the Walnut Lane Bridge (1950) in Philadelphia, was designed by Gustave Magnel and features three simply supported girder spans with a centre span of 48 metres (160 feet) and two end spans of 22 metres (74 feet). He was the author of the first English textbook on prestressed concrete. He designed one of the first PC railway bridges in Europe and the first statically indeterminate PC bridge in the world.

Finsterwalder was a German civil engineer, bridge builder and designer, who revolutionized the construction means and methods for pre-stressed concrete bridges. He invented the free-cantilever construction method of pre-stressed concrete bridges. He successfully sought to show that pre-stressed concrete could compete directly with steel not only in cost but also in reduction of depth. In 1951, according to his design, the 62 m wide stretched Lahn bridge in Balduinstein built as the first prestressed concrete bridge in the free porch. 

C. J. Bernhardt was the professor of Division of Concrete Structures, The Norwegian Institute of Technology, The University of Trondheim, Norway. In 1952, he published “SiO2 Dust as an Admixture to Cement”, which is considered as the first research paper on the use of silica fume in concrete. [In 1944, James William Sharp obtained patent for “Silica Modified Cement” (Patent No. 2,410,954 approved in 1946)]. In his research works, Bernhardt worked with up to 30% cement replacement and reported a significant increase in compressive strength. He had documented improvements in sulphate and freeze-thaw resistance in concrete mixes with 10-15% cement replacement. 

Professor A. M. Neville was born in Poland and is considered as “the ultimate global authority on concrete”. Adam first came to England at the age of 15 to study, when he won a scholarship from the British Council for an essay written in English. He returned to Poland in 1939 to be with his family. During the invasion of Nazi Germany and Soviet Union he tried to escape but was imprisoned by the Russians, serving 18 months at a hard labour camp in Siberia when he was still only 16, in terribly harsh conditions. In 1941 he was freed following the Soviet amnesty for Polish prisoners and managed, alone and in very poor health, to reach Iran, where he joined the Free Polish Forces under British Command. Here he finished his high school education, and thus became an officer in the Forces, and was reunited with his mother, who was serving as a pharmacist in a Forces field hospital. Adam served in Persia, Iraq, Palestine and Italy with great distinction. He was decorated four times for gallantry and was awarded the Cross of Monte Cassino and the Polish Cross of Valour for exceptional courage. When the war ended, Adam returned to Britain and studied at Queen Mary College, London, where he was an outstanding student, gaining (in 1950) first class honours in engineering, followed by a master’s degree. Almost this time he started to grow his famous handlebar moustache, which he kept until his death. It was whilst in Nigeria (1963) that Adam wrote his seminal book, Properties of Concrete, known by engineering students and qualified engineers alike as the ‘Concrete Bible’ and the last word upon concrete. It has been translated into 13 languages and has sold over a million copies, with the completely revised fifth edition published as recently as 2011. Adam joined the University of Leeds in 1968 as Professor and Head of the Department of Civil Engineering. He encouraged women to take up engineering study and careers, an approach for which his department became famous. Adam left the University in 1978 to become Vice-Chancellor and Principal of the University of Dundee. In 1987 he retired to become an engineering consultant.

James P. Romualdi was the professor of Carnegie Mellon University in Pittsburgh, Pennsylvania. In the late 1950's, James Romualdi became interested in composite materials and the principles of 'crack arrest' and fracture analysis. Romualdi was the first to utilize the application of these principles to PCC and is presently known as the father of “fiber reinforced concrete”. Professor Romualdi holds one of the key United States patents (patent no. 3,429,094 dated in 1969) on the use of randomly distributed short and thin steel fibers to reinforce concrete. In 1965, he published “Effects of impulsive loads on fiber-reinforced concrete beams” along with Melvin R. Ramey for Office of Civil Defense Office, Department of Defense.

V. M. Malhotra received his B. Sc. Degree from University of Delhi, India and B. S. in civil engineering from University of Western Australia, Perth. He joined in Canada Center for Mineral and Energy technology (CANMET) in 1962. Dr. Malhotra has made outstanding contributions to many areas in concrete technology, such as testing, materials and education. He is particularly known for his original research in accelerated strength testing, non-destructive testing, and development of the ring-tension apparatus for determining the tensile strength of concrete. His research on high volume fly ash concrete is of considerable global significance because of its economic, energy and environmental implications. In 1970, he published his papers on ring test, “Concrete Rings for Determining Tensile Strength of Concrete” (ACI Journal, April 1970) and “Effect of Specimen Size on Tensile Strength of Concrete” (ACI Journal, June 1970). His major books include,”Condensed Silica Fume in Concrete” (1987), “Pozzolanic and Cementitious Materials “(1996), and “Handbook on Non-destructive Testing of Concrete” (2003).

Ken was born in Yorkshire, UK and is known for statistical quality control and specific surface mix design. Ken was a good scholar and qualified for a government scholarship to University where he studied for Civil Engineering degree. After working for a year with Unit Construction Ltd, in London as an assistant to the Technical Director, he moved to Melbourne in 1953 to join Humes Ltd, a pre-stressing facility. At the Research and Development Laboratory of Humes Ltd. in Melbourne Ken was involved in mix design and QC on precast pre-stressed concrete projects and in several other States of Australia. In 1957 he became R&D engineer and deputy technical manager of the semi-government Concrete House Project, producing 5 fully precast houses and flats per day in a factory. In 1960 he took a position as lecturer in Concrete Technology at the University of NSW in Sydney. He registered for a PhD but did not complete it. Next he had a brief period in 1962 as technical manager of Marley Reliance in Sydney. Marley had two ready mix plants and several factories producing precast concrete, spun pipes, masonry blocks and roofing tiles. The firm had a poor quality reputation and Ken left due to being unable to obtain sufficient management support to correct this.

Then he returned to the UK and spent 5 years as a structural consulting engineer, rising to Associate Partner of Harris and Sutherland. He returned to Australia in late 1967 as general manager of the Melbourne pre-casting company, High Strength Concrete Pty Ltd. In 1973, Ken returned to his first love of concrete and he started his own company, Concrete Advice Pty Ltd. In 1985 due to a down turn in the business in Australia the company was left inactive while Ken spent two years working with the Australian Government Airfield Construction Branch and became an Australian citizen. It was mainly during this period that the Conad system was finalised. 

Ken modified the calculation for specific surface mix design. He was an ardent proponent of cusum analysis for quality control. At the age of 70, Ken decided to retire from his business. He will be remembered best for is being the leader in the whole field of statistical quality control for concrete and in the development of ConAd system computerizing mix design and QC in his ConAd program.  

Bryant Mather was one of the foremost experts on concrete in the US. He was a member of ASTM for over 55 years and president of the Society from 1975 to 1976. Dr. Mather had retired in 2000 as the Director of the Structures Laboratory of the U.S. Army Corps of Engineering Vicksburg, MS. 

 After receiving a bachelor's degree in geology from Johns Hopkins University in 1936 and completing postgraduate study, Bryant took a position as a curator with the Field Museum of Natural History in Chicago, IL. In 1941, he accepted an engineering assignment as a junior geologist with the Central Concrete Laboratory at the U.S. Military Academy at West Point, NY, thus beginning a long, illustrious career associated with concrete technology. Dr. Mather started his ACI membership in 1944, and throughout the years, he was extremely active in ACI technical committee work, serving on 17 different committees with an accumulated total of 288 years of participation. His research interests were structural geology; composition and properties of concrete and concrete aggregates; methods of testing (particularly of dams); and butterflies and moths of Mississippi. He had received the following awards: Sanford E. Thompson Award (1961); Frank E. Richart Award (1972); Henry C. Turner Medal (1973); Charles S. Whitney Medal (1974); William T. Cavanaugh Award (1990); and Robert E. Philleo Award (1992). Mather was also a member of American Association for the Advancement of Science; the Meteoritical Society; the American Concrete Institute; the American Institute of Mining, Metallurgical and Petroleum Engineers; and Sigma Xi. President Carter made him a charter member of the government’s Senior Executive Service in 1979. His major works include, Effects of Sea Water on Concrete (164), Alkali Reactions with Carbonate Rock (1964), Investigation of Expanding Cements (1963), Investigation of Portland Blast-Furnace Slag Cements (1965), Concrete Deterioration (1966), Admixtures for concrete (1967), Behavior of Concrete Exposed to Sea (1970), Concrete Durability (1987), and Concrete Primer (2002).

Professor Joseph Davidovits was born in Villers St Paul, Oise, France. He is known by the scientific community for being the inventor of geopolymer science and geopolymer concrete. He posited that the blocks of the Great Pyramid are not carved stone but mostly a form of limestone concrete or man-made stone. This odd theory is officially endorsed by several renown materials scientists. In 1958, he obtained a chemical-engineer degree, followed by a Dr.rer.nat in organic polymer chemistry at the University of Mainz, Germany in 1960. In 1964, he received the Annual Award from the French Textile Chemical Society for his work on linear organic polymers. In 1969, he is hired by the French textile company, Delcer Industries. The geopolymer concept was created and published in 1979, together with the foundation of the non-profit scientific organization Geopolymer Institute, Saint-Quentin, Aisne, France. In 1983, he was appointed Professor of Chemistry at Barry University, Miami, Florida, and there he founded the Institute for Applied Archaeological Sciences (IAPAS) to study worthwhile ancient technologies and advance the clarity of ancient history. Between 1983 and 1989, in collaboration with Lone Star Industries of the United States, he developed the geopolymer cement called PYRAMENT and its associated cement blends. He is the President of the Geopolymer Institute and Chair of the annual conference Geopolymer Camp, Saint-Quentin, France.

Professor Hajime Okamura is President of Kochi University of Technology, Kochi, Japan. From 1966 to 1998, he was faculty member at the University of Tokyo and was conferred the title of Professor Emeritus in 1999. Okamura is better known as the “father of self compacting concrete”, who has proposed the idea of self compacting concrete in 1986 and developed it by 1988 along with Osawa and Maekawa. Okamura was born in 1938 in the city of Kochi in Japan. He graduated with civil engineering in 1961 and after master’s degree (1963), completed his doctoral research in 1966 at the University of Tokyo. Okamura has noticed that creation of durable structures required adequate compaction by skilled workers and lack of skilled workers in Japan’s construction industry has led to reduction in the quality of construction work. One solution was to develop a self compacting concrete, which can be compacted into every corner of a formwork, purely by means of its own weight and without the need for vibrating. The prototype of self-compacting concrete was first completed in 1988 using materials already on the market.

Professor Mario Collepardi was born in Ausonia, Italy. He completed his degree with honors in Industrial Chemistry at the La Sapienza University of Rome in 1961. He has taught at the Faculty of Engineering of the Universities of Cagliari, Rome, Ancona and Polytechnic University of Milan. In 1989 he was awarded the CANMET / ACI with an award for his "significant contribution to the knowledge of super plasticising admixtures for concrete". In October 1997 the ACI, CANMET and the Canadian National Research Council (NRC) organized a symposium in Rome named "Mario Collepardi Symposium: Advances in Concrete Science and Technology" in recognition of the intense activity professional, didactic and research in the field of building materials. In April 2007 he was nominated Honorary Member of the American Concrete Institute (ACI). In 2014 he became Honorary Member of AICAP - Italian Association of Armed and Precompressed Cement. Publications: he is author and co-author of about 400 publications, several books on concrete, software for mix design and specifications of concrete specifications, as well as five international patents in the field of super fluidifying additives, silica fume, and expansive cements and of the structural restoration mortars. Among the published most important are, “Concrete Science and Technology"(1979), "Mix design of concrete"(1990) "Foundations of Concrete Technology"(1991) "Innovative materials for special concretes"(1990), "Durability and restoration of concrete works"(1992), "Materials in Historic Buildings, Degradation and Restoration"(1991), "The New Concrete"(2001), "Mix Design of Concrete"(2008). Collepardi has been credited with many patents like “Pozzolanic compositions” (No. 5762701, 1998), and “Zero slump-loss superplasticizer” (No. 5362324, 1994).

Pierre-Claude A?tcin is Professor Emeritus in the Department of Civil Engineering of the Faculty of Engineering at the University of Sherbrooke, Sherbrooke, Quebec, Canada. From July 1990 to April 1998, he was the Scientific Director of Concrete Canada, the Network of Centres of Excellence on High-Performance Concrete, a network of 15 teams of researchers from several Canadian provinces. Aitcin is known in the concrete industry as the “father of high-performance concrete”. The concept of high-strength concrete came up in the 1970s, when the compressive strength of concrete used in the columns of some high-rise buildings was higher than that of the usual concrete used in construction at that time. Aitcin further developed the idea of high-strength concrete to high-performance concrete, which has not only high-strength but also high flowability, higher elastic modulus, higher flexural strength, lower permeability, improved abrasion resistance and better durability. This was possible due to the developments in superpalsticizers which allowed the use of low water/cement (binder) ratio mixes along with supplementary cementitious materials. Aitcin published his book titled “High-Performance Concrete” in 1998.

This article is a comprehensive compilation of available literature and website data on the titled subject. The author did not invent anything new, but pays humble homage to the great lives. The author would like to request the readers to highlight the errors and omissions. The article is not complete.. and never it will be.

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