Portland Cement Association (n.d.) stated that in the simplest form, a blend of paste, stone, sand and water is a concrete. Concrete is one of the fundamental building block of the civilization, contributing to all the structures across the world. Concrete can be viewed in details in term of its constituent materials, properties, durability and concrete mix design and quality control.
Constituent materials are the fundamental materials required to produce concrete. The constituent materials of concrete consist of mainly three materials which are cement, aggregate and water, with admixtures included as addictive to alter the characteristics of the concrete (Scalenghe et al., 2011). “Cement is the chemically active constituent but its reactivity is only brought into effect on mixing with water” (Dhir & Yap, 1984). According to Bye (1999), in the industry, Portland cement, which was developed in 1824 by using calcium carbonate found in calcareous rocks, namely limestone or chalk and silica, alumina, and iron oxide found in sedimentary rock, namely clay or shale. Bye (1999) said that cement is produced by grinding the quarried limestone to powder form, blending it with water and heat with pulverized coal to drive out water at 100°C, carbon dioxide at 800°C and clinker at 1400°C, which is then cooled, grounded and mixed with 1%-5% gypsum to alter it fineness and goes through final grinding and the cement is ready to be distributed to the market. According to Sismondo & Sergio (2009), aggregate, which builds up the majority of the volume stability and the durability of the resulting concrete and is of lower price than cement, is always used to the maximum extend as possible in the production of concrete for maximum profit. Aggregates ar...
... middle of paper ...
...s.
Portland Cement Association. (n.d.). Concrete basic. Retrieved October 29, 2013, from http://www.cement.org/basics/concretebasics_concretebasics.asp. Price, W.H. (1951) Factors influencing concrete strength, J. Amer. Concr. Inst., 47 (2), pp. 417-419.
Rixom, M.R. (1978) Chemical Admixtures for Concrete. London, UK: Spon.
Sadegzadeh, M. and Kettle, R.J. (1986) Indirect and non-destructive methods for assessing abrasion resistance of concrete, Mag. Concr. Res., 38 (137), pp. 183-186.
Scalenghe, R., Malucelli, F., Ungaro, F., Perazzone, L., Filippi, N., Edwards, A.C.
(2011). Influence of 150 years of land use on anthropogenic and natural carbon stocks in Emilia-Romagna Region (Italy). Environmental Science &
Technology 45 (12), p. 5113.
Sismondo & Sergio (2009). An introduction to science and technology studies (2nd ed.).
Milton, Canada: John Wiley and Sons.
they're not. Concrete is to cement as a cake is to flour. Concrete is a mixture
Besides the known inventions and renovations of the Roman Empire, one of the building materials that the Roman Empire produced was concrete. With its strength, inexpensiveness and its easiness to work, the Roman Empire left an everlasting impact. Concrete that is a mixture of aggregate, which is usually gravel, sand or small stones, binding agents, and water is used to construct buildings and infrastructure. The first one, aggregate, gives the product its mass while the second one, binding agents, is used to harden the product. In the early times of the history, limestone powder was usually used as a binding agent in the mixture. The Romans later used “pulvis puteolanus” (pozzolanic ash), which was a fine volcanic ash as a binding agent and it allowed Romans to have strong concrete that is also durable (Yegeul, n.d.). It was easy to use
At first the Romans did not realize the superior ability of concrete. They began by using it as a fill. They would also cover up the concrete with decorated stones. The concrete they used did not look pleasing because they had mixed it with any arrogate they had available. Later, once they discovered how useful concrete could be, they used it for everything they could. They built their houses, roads government offices, theaters, temples, and everything else they could out of concrete. Concrete was far superior in strength to stone and mortar, and it was easier to make than marble was to quarry and assemble.
If the ancient Roman innovation of concrete, were to not have been significant, it would not have continued to be used across the globe. In fact, ancient Roman hydraulic cement-based concrete was so notable that modern day scientists are trying to, “replicate the exact formula for which ancient Roman concrete was made.” This is due to ancient Roman concrete being so sturdy and strong that aspects of it have lasted over 2000 years without deterioration. Without the innovation of Roman concrete, many of the modern world’s infrastructure would not be stable, causing havoc across the globe. Also, advancements in construction, health, and even safety areas would not be possible, as almost every piece of infrastructure, from sewerage and water pipes, to building and security walls, would not be able to remain as safe to use. This is because the modern world relies so heavily on concrete, with around five billion tonnes of concrete being used around the world each year,becoming the single most widely used material in the construction industry. In fact, around 76% of all first-world infrastructure is reinforced with concrete. Without this substance, much of the modern-world's infrastructure would not be as tall or sturdy as what it currently is, as it would simply deteriorate or break. Hydraulic cement-based concrete is certainly the most significant Roman
Calcium Chloride is wanted for a crime in Atom-city. If you have any information of the whereabouts of Calcium Chloride, please contact sheriff Cassie Mes.
Denture teeth can be made of acrylic poly(methyl methacrylate) (PMMA) or composite resins. PMMA is a polymer - a material made the from joining of methyl methacrylate monomers. Properties of PMMA include resistance to abrasion, chemical stability and a high boiling point. (Jun Shen et al. 2011). However, weak flexure and impact strength of PMMA are of concern as they account for denture failure. (Bolayir G, Boztug A and Soygun K. 2013). Composite denture teeth are made of a three distinct phases - filler, matrix and coupling agents. Out of the types of composite teeth available, nano-filled composite teeth are preferred. Composite teeth have a PMMA coating around the tooth and a high content of filler particles. This gives them strength, higher resistance to forces than acrylic teeth and provides compete polymerization due to the PMMA coating. (Anusavice, K. J., Phillips, R. W., Shen, C., & Rawls, H. R, 2012). If the interface between the PMMA denture base and PMMA or composite teeth was weak, the denture will not be able to sustain occlusal forces, making the base-teeth interface, an entity of significance.
The following information will focus on the two substances forensic scientist use to identify and compare matter, whether a material is organic or inorganic. Evidence that will be used in a court trial will depend on the examination that forensic scientist processed in the laboratory. The importance of distinguishing between organic and inorganic material is a necessary step in the criminal justice process. The differences between organic and inorganic will be explained first, next will be to explain the strengths and weaknesses of each, and finally the significance of both as it relates to the justice system. Also, we will focus on soil as it relates to how specific evidence is used in each instance. Now let’s begin by listing the differences.
The Pantheon was a Roman concrete structure. Roman concrete is a mixture of lime and volcanic ash (pozzolana, found near modern-day town Pozzouli). Roman concrete is also called hydraulic cement-based concrete. It is known for curing relatively rapidly, even in damp condition, thus it could be used for massive construction. The most daring thing about the use of Roman concrete in the Pantheon is that Portland cement needs steel reinforcement due to tendency of cracking caused by tension forces, meanwhile the Pantheon did not. The Pantheon still stands today is because of its special structure.
Dental materials are used for a variety of reasons. The basic reason for using dental materials is to restore the tooth back to its original anatomy. Some materials are used more than others but it depends on their characteristics. Composite resin is a type of dental material. Some dental materials do not have the esthetic characteristic that composite resin has. That is why sometimes, it is more favorable than other dental materials. It is one of the most common dental materials that are used to restore a tooth back to its natural appearance.
Concrete is one of the world’s most popular construction materials. Some six billion tonnes of concrete is produced each year in the world, making it approximately one ton of concrete for every human being per year (Fardis, 2012, p.116). However, the lifecycle of concrete does not make it the most sustainable building material at the moment. Because of limited natural resources, concerns over green house gases, and landfill problems, concrete production is being cut-back, or at least cannot be increased to keep up with population increase. In this essay, I will look at what makes concrete an unsustainable material and possible solutions to make concrete a more sustainable material.
Nowadays, it will not be inept to inform that the universe is going over a construction boom. In truth, in the past few decades an entire affair of construction has altered dramatically like all other aspects of life. Currently, construction is no more just about keeping one brick above the other, but a diverse more than that. With the present scenario, the construction work encompasses all the aspects of construction like, performance, optimization, developing and designing. As an outcome, construction chemicals have become an essential part of the world construction industry. These chemicals are typically utilized to impart different properties into the layout.
Aluminum is one of a number of soft metals that scientists call "poor" metals. It can be shaped and twisted into any form. It can be rolled into thick plates for armored tanks or into thin foil for chewing gum wrappers. It may be drawn into a wire or made into cans. Aluminum is a generally popular metal because it does not rust and it resists wear from weather and chemicals. (Bowman, 391) Aluminum is an element. Its atomic number is thirteen and its atomic weight is usually twenty-seven. Pure aluminum melts at 660.2ºC and boils at 2500ºC. Its density is 2.7 grams per cube centimeter. Aluminum is never found uncombined in nature. (Bowman, 391) Aluminum is a very useful metal that is light, easy to shape and can be strong. This makes aluminum one of the most used metals in the world, right behind iron and steel. (Geary, 185) In its pure state, aluminum is quite weak compared to the other metals. However, its strength can be greatly increased by adding small amounts of alloying elements, heat-treating, or cold working. Only a small percentage of aluminum is used in its pure form. It is made into such items as electrical conductors, jewelry, and decorative trim for alliances and cars. A combination of the three techniques has produced aluminum alloys that, pound for pound, are stronger than structural steel. Some common metals used in alloys for aluminum are copper, magnesium and zinc.(Walker, 31) The added elements give the aluminum strength and other properties. (Newmark, 41) Aluminum is one of the lightest metals. It weighs about 168.5 pounds per cubic foot, about a third as much as steel which weighs 487 pounds per cubic foot. (Neely, 214) As a result, aluminum has replaced steel for many uses. For example, some ...
Concrete is a composite material used widely in the construction industry. Concrete is basically a mixture of cement, water, aggregates and admixture (sometimes). Cement is a fine gray powder that consists of oxidizes calcium, silicon and aluminum. The aggregate used is normally gravel, crushed stone or sand. Admixture is a solid or liquid substance that gives a certain characteristics of the concrete. The cement reacts with water chemically and binds the aggregates together through a process called hydration during hardening or curing of concrete. It means that water helps in the hardening of the concrete while the cement bind the aggregate and also react with water to form a solid mass.
The buildings that were used in Rome were once made out of the simple volcanic rock and lime to form concrete. Concrete was able to work as a strong paste molding together to form buildings that were needed in Rome. Buildings in Rome that were made out of concrete were homes, coliseums, and even religious houses. In order for other civilizations to function and stay strong they were in need of these type of buildings too. Many civilizations were able to realize Rome’s strong towns full of buildings and systems made out of concrete, and for others to continue on in their daily lifestyles they would need concrete too. For an example, in the Philippines, they used limestone rocks and ancient cement structures from Rome to build their houses. Other civilizations like the Mycenaean’s have created a place for the government just like the Roman’s built Forum’s out of concrete. In other times after the Romans, the Nabataeans built of their ideas and started making cement. It was waterproof cement, they called pozzolan. They used the cement to build houses, kitchen utilities and places for markets. The Roman’s cement ideas were so successful
Opus caementicium or Roman concrete is a synthetic construction substance that’s composed of an aggregate, a binding agent, and water. In Rome’s case, as discovered by UC Berkley with the extensive analysis of a sample of Roman concrete taken from a breakwater in Italy’s Pozzuoli Bay it was developed by using lime and volcanic rock which formed a mortar, the mortar and volcanic rock were then packed into wooden forms and when seawater was added a chemical reaction occurred, bonding everything together to create concrete (History, 2013). It is uncertain when Roman concrete was developed, but it was clearly in widespread and customary use from about 150 BC; some scholars believe it was developed a century before that.