Critically evaluate different models of corporate governance. What Essay

Critically evaluate different models of corporate governance. What implications do these models have for meeting the growing de - Essay Example Models of corporate governance The difference of contexts, in which the governance is made, brings variations in corporate governance model. It is not a single rigid structure that might describe the pattern of corporate governance in every country in the world (Morck, Wolfenzon and Yeung, 2005). There are three distinguished models of corporate governance: The Anglo-US Model Equity financing is commonly used as a technique of raising capital by private corporations in the US and the US. By virtue of this practice, the US is known for having the world’s largest capital market. A causal relationship exists between equity financing and the size of capital market which affects the development process of Anglo-US corporate governance system. The important participants in the Anglo-US model are the board of directors and the shareholders or institutional investors. Government agencies and other regulatory organizations also form a part of corporate governance model. ... Japanese model The Japanese model exhibits high stock ownership by private companies and banks. In this model, a banking system is characterized by strong and long-term links with corporations operating with the banking system. Equity financing holds an important position in the workings of Japanese corporations. However, the major shareholders in these corporations are the insiders and their affiliates. In this model, interests of the outsiders are marginal. A very small percentage of Japanese stocks are owned by foreign investors. In Japanese corporate governance, as contrasted with Anglo-US model, non-affiliated shareholders do not have a concrete position. Hence, truly independent directors, representing the outside (or foreign) shareholders, are present in very few numbers (Li, et al., 2012). Figure 2: Open-ended hexagon (Source: Emergingmarketsesg, 2011) German model The German model of corporate governance differs remarkably from both the models discussed above. There are cert ain distinctive elements of the German model, which distinguish it from the other models discussed in this paper (Ahrens and Khalifa, 2013). In most German corporations a traditional preference towards bank financing is noticed over equity financing. This shows that stock market capitalization in Germany is much smaller compared to the size of German economy. In addition, individual stock ownership is also very low in Germany, which is indicative of the factor that German investors are risk averse and adopt conservative investment strategy. Corporate governance structure in the country is strong intention of preserving long term relationships among the key economic agents, i.e, the banks and private corporations (Emergingmarketsesg, 2011). The system is inclined towards

How has Islamic religion influenced American culture Essay

How has Islamic religion influenced American culture - Essay Example re are many points that should be taken into account as well as there are traces that should be identified as those that are largely affected by Islam. That is why exploring the issue in question may be particularly beneficial since it sheds light on the true nature of both parties. This paper will analyze how Islamic religion has influenced American culture. In order to do so, it may be necessary to examine some of the earliest encounters between the religion in question and the United States. Afterwards, the concept of religion in general will be explored, namely how Islam is able to be included into the Christian dominated social environment. The next important aspect is education: Islam is known to have a considerable impact on the educational process and this largely shapes the latter. The issue of Muslim identity should also be carefully examined since it is able to highlight the major aspects of each of the side involved. The paper will also focus on the negative impact that i s often attributed to Muslims and how it defines the modern culture. It is rather obvious that some people might argue that the history of interaction of Islam and the United States started relatively not so long ago. However, these people tend to forget that Muslims did not only appear in America at the time of its created, but also contributes towards its emergence. By far, the Civil War is one of the major historical events in the history of the United State. So, if one carefully analyzes the demographics of the soldiers who fought for the North, one will be able to see that there was a considerable number of Muslims. With this is mind, it is obvious that people who belong to this faith greatly contributed towards the very appearance of this culture. Indeed, the aftermath of the Civil War resulted in an â€Å"increased ethnic and racial diversity and the heterogeneity of religious life in America †¦ called for the rethinking of the essential character of America† (GhaneaBassiri,

A Manifesto Essay Example | Topics and Well Written Essays - 1250 words

A Manifesto - Essay Example With regard to its aesthetic qualities, it has the qualities of beauty, harmony and symmetry where none can be taken or added that would not impair the totality of the design. My initial role in design is to first learn to create a good design. A good design requires multidisciplinary approach which includes ability to draw, manipulate computer, take pictures, understand color theories and to create concepts through images that people could understand. After learning these things, my role then transformed to be able inspire, create, improve and learn. I believe that a good design is a product of inspired moment that is aptly captured and have physical attribute for others to be inspired as well. That process of giving inspiration a physical attribute so that others may see is the creative process of rendering the inspiration. This creative process however is never completed and must constantly be improved to optimize the best design possible. On my end, I must also continue to learn so that I can better render the inspiration that I have. I treat design as an artwork. My value towards it similar to fine artists and painters who would first look and feel for an inspiration and then make that emotion to be felt in their work. I could also say that my life is reflected in my designs. It is because my design is the expression of myself. And myself is the collection of my experience, knowledge, beliefs, hopes, aspirations, my sense of beauty, or anything that made me a person. And this is expressed and seen in my design. Getting it out of me to make a good design is not an easy process and could take time but I believe that it will be worth the effort because the output would surely be beautiful. My personal values about design are a lot. Firstly, I truly believe that art imitates life. In this aspect, graphic design is one of the expressions of art. Design is an expression

Why kids attract towards animation and 3d animated films Essay

Why kids attract towards animation and 3d animated films - Essay Example Bentrancourt and Chassot (2008, p. 3) highlight that the fundamental reason why kids are attracted towards animated films is due to the visualizations they create, which helps in overall understanding of situations. Further, it is claimed that animations are very helpful for kids because they enhance memory of the animated information which later aids to advance comprehension of various situations depicted by the animations. Therefore, it is observed that animations are attractive to children because they create memorization and comprehension of whatever subject they illustrate. Moreover, kids are attracted to animations and 3d animated films because they are funny and entertaining to watch. Therefore, they are very appealing, humorous, motivating and most often capture children’s attention. In their tender age and little comprehension abilities, kids get bored when watching television, hence, they are usually inclined to watch more fun and entertaining programs than TV programs, which are mostly in the form of animations (Shanghai Jianghong Gifts, 2008). For example, if children were doing their homework at home and an adult was watching news, they are likely not to develop any interest in the TV. However, if the channel is changed to a cartoon program, the kids will lose interest in the homework and will be motivated to watch TV. This proves that kids are attracted towards animated films because they are fun and entertaining to watch. In addition, kids are attracted to animation films because animations use space in representing elements in their relations. In this case, animations create characters that kids are able to relate to and themes which make character differences and this attracts them to watch animated films. Therefore, when kids watch animated films, they also develop favourite characters who might be good in the film. Hence, this will give the

Philosophy of Music Education in the Indian Context Essay Example for Free

Philosophy of Music Education in the Indian Context Essay These goals must be the first and foremost reason why we teach music. To instill an even greater understanding and love of the domain thus enabling our students develop a genuine interest and continue a life long journey that’s undertaken in varying degrees and through diverse roles. Phenix (1986) stress on the fact that knowledge of methods makes it possible for a person to continue learning and undertake inquiries on his own (p. 11). Estelle Jorgenson in her book â€Å"Transforming Music Education† eloquently describes the need for music education to be transformed for the very reason that children be able to continue developing their knowledge beyond the classroom. Effective music education is built of a foundation that encompasses discussions, goals, materials and strategies, based on a teacher’s knowledge and experience of music and child development, educational guidelines and â€Å"overarching, and developing philosophy of music education† (Fiske, 2012). Before I elucidate my philosophy about music, I recognize the need to clarify my stand as a music educator who is passionate and determined to elevate the status of music education within classrooms around India. My Musical Experiences Music has always been a part of me for as long as I can remember. My earliest memories of music, especially the performance aspect, goes back to when I was three years old and sang a solo for a Christmas Concert that was organized by the radio station that my father worked at. I have memories of him kneeling on one knee and playing the guitar for me while I sang after which I was delighted to receive a big present from Santa. Ever since, I have enjoyed performing, and have so felt so comfortable on stage. All along I grew up listening to Christian gospel music and many contemporary arrangements of hymns. Supplementary to that my father offered me a rich experience of Indian hindustani devotional music. I learned songs by ear and didn’t realize what I was missing at this point, imagining what I learned in music to be the only way to absorb and internalize it. Performing was something that I enjoyed doing and it came naturally to me, partly because of my early initiation into leading worship at church. My true test of endurance came about when I was introduced to Western Classical Music at the age of 14, through the study of two years of piano. My teacher, like many others around, displayed an extremely formalistic approach and didn’t do much to expand my understanding of music beyond what was on the page and how I was supposed to read it. In response to this method I didn’t enjoy learning from the pages of notated music books, as much as I did learning by ear, and I continued to develop as a musician who played by ear and improvised at will. Studying opera during undergrad was a trying phase for me because of my inability to â€Å"connect the dots† as easily as I should have been able to. My aural skills remained excellent and I sometimes relied on that to carry me through certain phases. Hard work and determination became my motto, and I spent hours to understand and perfect music that was assigned to me, as I wanted to do my very best. Although I had composed songs earlier, without notating them, the study of music theory opened up a whole new world for me. I could now add variety and richness to my music through the concepts I was learning. Music became a new language for me; I was captivated by the way it lent itself to diverse experiences through different musical roles (something that I wasn’t aware of or didn’t pay attention to earlier). As a Music Teacher Although I initially joined a conservatory to study vocal performance, I found myself deeply drawn towards music education, and during my second semester decided to learn more about devising meaningful and persuasive trategies to improve the standard of music education in India. This thought emerged from an understanding that I had felt almost cheated for having lost out on so many years of studying music formally, yet effectively. I didn’t have a choice because structured music instruction simply wasn’t available at all the schools that I studied in, or the quality of instruction didn’t serve the purpose of educating or informing students like me. What gave the impression of a music class/lesson at school was in reality an enthusiastic way of keeping students occupied for forty minutes in simple singing, with a concert for parents every once a year. We learned songs by rote to perform them, year after year. During those years though, I didn’t realize the limitations that this system came with and continued to enjoy the fact that I was in choir and able to sing. This vacuum remains largely visible and unattended to in schools today, although some music educators in the recent past have taken huge steps towards improving the quality and effectiveness of their instruction in classrooms around India. Their efforts however remain predominantly an enthusiastic endeavor. What is urgently required is certainly something much more than sincere teaching. It calls for a transformation of the present system, giving room for every child to receive superior music education that fits into the whole. The need of every student being met in a transformed educational framework that constantly reshapes itself to accommodate new ideas and strategies. After all, as Regelski (2003) rightly points out that music (music education) is for everyone and not just for an elite few. The turning point in my decision to finally teach music myself came about when I enrolled my four-year-old daughter, Tiara, for after-school piano lessons. I hoped to give her a head start, with the understanding that she needn’t have to face the same challenges in learning music, like I had to. However, after a few classes, I realized to my complete dissatisfaction that there was no structure, no thought and imagination, and no clarity in what was being thought to her. Her fingering on the piano was all over the place for the two songs that her teacher worked on â€Å"Twinkle, Twinkle Little Star. † And â€Å"Baa Baa Black Sheep† Her teacher (I later learned wasn’t introduced to classical notation), taught her these songs by writing letters in a book and instructing her to commit it to heart. Lesson after lesson they would follow the same outline with no emphasis on any other musical aspects whatsoever. I decided I wasn’t going to take this lying down! I had to do all within my capacity to change the face of music education, as the vast majority of people understand it. I began studying about music education as well, to inform and equip myself for the task at hand. Around this period, my voice teacher encouraged me to coach students in voice, and I began shying away from it believing I was under qualified and needed many years of study to begin teaching. However, with a newfound passion and vigor, I accepted to coaching some of his voice students and also began to teach small groups of students on the history of music (because I loved learning about it). Meanwhile, I started training both my young daughters at home constantly developing new ideas and strategies to introduce musical concepts to them. A friend noticed my teaching style and asked if I would teach her daughter too, and thus began my professional journey as a music educator. Four years since then, I find myself accountable for the music instruction I offer to over 250 children across various age groups, who are part of my school. The need is so great within schools, and only a few educators are willing to take the extra effort of educating themselves and being channels of superior music instruction-catalysts of sorts. I am blessed to have a team of ten teachers who share in my vision and work alongside me in imparting music to the children who are part of our music school, â€Å"Harmony†. My long-term vision is to enhance the music programs in India for the betterment of as many children as possible. Individuals don’t realize what they’re missing until they’ve been given a taste of it, a glimpse of the bigger picture (much like my case). Through our school performances I aim on providing a window for the change to take place. A transformation that not only affects my students, but others around them as well through their personal interactions with each other and the community as a whole. My Personal Philosophy â€Å"A field or discipline without philosophical guidance, without critically examined ideals and commitment to their revision in light of the diverse and changing needs of those it seeks to serve, is more akin to an occupation han a profession† (Bowman Frega, 2012, p. 23). For my vision to bear fruit and show evidence of becoming something concrete, I realize the need to develop my philosophy of music to an extent that equips me with the requisite tools to be able to initiate the change that I seek after. In the words of Jorgenson (2008), â€Å"I want to excavate beneath the superficial and demonstrable skills to think about the ideas and principles of music teaching, the things that drive and shapeà ¢â‚¬ . According to Kivy (2002), â€Å"A practice or discipline or body of knowledge, then, seems to become ‘eligible’ (If that is the right word) for philosophy, properly so–called, when it becomes for us a way of life: when it cuts so deeply into our natures as human beings that we are impelled to explore and reveal its innermost workings† (p. 7). It is necessary for me to â€Å"clarify the major dimensions of musical experience† so I can â€Å"effectively offer them to, and nurture them within, â€Å" my students (Reimer, 2003, p. 9), this despite the passion and conviction with which I teach and advocate the need for arts in schools. I have begun to develop a synergistic mindset in my philosophy of music education after my reading and researching the literature, coupled with practical experiences over the last few years. Reimer (2003) points out â€Å" A synergistic mind-set is one open to cooperation as an alternative to contention, to searching for points of agreement or confluence as an alternative to fixating on discord, to recognizing nuances in which seemingly opposed views are capable of some level of contention† (p. 30). I agree with Reimer’s democratic view that musical meaning is meaning that â€Å"individuals choose to give to and take from music, based on their life experiences and their musical orientations. † He further adds that there is to be no â€Å"one right way†, and calls for an adaptation of a synergistic blend in music teaching. Music must involve decision making through discernment and connections within a particular role (Reimer, 2003, p. 213). Eisner (1987) illuminates the need for a curriculum that â€Å"exploits the various forms of representation and that utilizes all of the senses to help students learn what a period of history feels like†(p. 7). Similarly, offering students a basis for understanding music in all contexts involves a thorough exploration of musical meaning within its definitive parameters, along with contemplation or reflection. Introducing students to the music and other art forms of various cultures is a wonderful way to broaden their understanding of the meaning of music. A student does not need to lose his own musical identity in order to study other music. On the contrary, in learning about other music, a student’s life is enriched. Reimer states, â€Å"In the spirit of adding to the self rather than substituting other selves for one’s self, the study of the music of foreign cultures enriches the souls of all who are engaged in it† (p. 191). Music and Meaning As advocates of music, music educators are often expected to express the meaning of music through words, yet words are incapable of truly describing the beauty and emotion felt through experience. â€Å"The concern is not to arrive at a definition and to close the book, but to arrive at an experience† (Ciardi, 1975, p. ). Ciardi states that there â€Å"still lingers belief that a dictionary definition is a satisfactory description of an idea or of an experience† (p. 1). Words may attempt to describe music, yet true meaning must be derived from the actual music experience Reimer (2003) discusses the difference between meanings drawn from words or language and the meanings found through music. He writes, â€Å"Language is created and shared through the processes of conceptualization and communication. Music is created and shared through the process of artistic/aesthetic perceptual structuring, yielding meanings language cannot represent† (p. 133). â€Å"The real power of music lies in the fact that it can be â€Å"true† to the life of feeling in a way that language cannot† (Langer, 1942, p. 197). Phenix (1986) highlights the need to look for aesthetic meaning in music concluding that there has to be a delicate balance between descriptive proposition that serves the purpose of laying out a historical background and allowing for freedom to gain perceptual features. Though music may evoke emotions in my students as they compose or serve as an outlet for their feelings when they perform, the ultimate significance of music lies in its ability to symbolize/portray deeply felt emotions. In the pages of his article, How Does a Poem Mean, John Ciardi (1975) shares with the reader his view that language is not capable of completely conveying the meaning that is discovered through experience. Living through the poetry is more powerful than attempting to interpret it. I believe that language does, however, serve a purpose of enhancing and is required when teaching for musical meaning. Words such as diction, metaphor, rhythm, and counter rhythm describe elements that lead to the understanding of form. Once a student can identify changes in the form through performance, â€Å"he will have identified the poem in action† (p. 95). He will no longer ask what the poem means but will see â€Å"how it means† (p. 95). Ciardi suggests questions such as, â€Å"Why does it build itself into a form out of images, ideas, rhythms? How do these elements become the meaning? † and â€Å"How are they inseparable from the meaning? † (p. 100). These questions are helpful in leading a student to the ultimate meaningful experience. Likewise, music students may use their knowledge of musical elements, such as rhythm and dynamics, to see â€Å"how† a piece of music means. Reimer (2003) says language has the essential function of disclosing and explaining the music. Music elements are inseparable from the performance of the music as they help to explain the musical experience. On their own, however, words and definitions remain dull and lifeless. I believe students should be immersed in the experience, while in a chorus, performing their instruments and listening to those around them. Meaning can be discovered through active participation in music and through the emotion and beauty the music portrays, for â€Å"Music means whatever a person experiences when involved with music† (Reimer, 2003, p. 133). Ciardi’s (1975) statement: â€Å"It is the experience, not the final examination, that counts† (p. 3) is particularly striking. The Indian society places high emphasis on examinations in music as with other subjects, very often overlooking the need for students to value their experience through the process of learning. I sometimes feel pressured by the community to meet high concert performance expectations and good examination results. Although I recognize that performance and the International music exams is a wonderful opportunity in which students can share their music with the community, or understand their level of competency, the true reflection of meaning in the music should be experienced in day-to-day music making within my classroom. I do my best not to focus on the examination repertoire alone but to include other music as well giving them a chance to draw out meanings and experience the music. Ciardi (1975) describes a poem as a â€Å"dynamic and living thing† (p. 10). He continues stating, â€Å"One experiences it as one experiences life. One is never done with it: every time he looks he sees something new, and it changes even as he watches† (p. 10). Similarly, music is capable of revealing something new each time it is experienced. The meanings my students derive from an initial listening of a piece of music may be vastly different than the meanings understood months or years later. The meaning of music constantly changes with personal life experiences and new perspectives. Reimer claims, â€Å"Music education exists to nurture people’s potential to gain deeper, broader, more significant musical meanings† (p. 133). I believe my students should derive their own meanings from the musical experience and without my influence. By explaining meanings to them, I face the fear of casting into oblivion the celebration of their own unique experience with the music, much the same way a language teacher might, in more ways than one, take away from the experience of a students â€Å"feelingful† experience of poetry as she explains the meaning in the verses of the poem. Instead of teaching â€Å"what† music means, I will instruct students on â€Å"how† music means, enabling them to derive meaning from experiences that occur beyond the classroom, and within their own roles. Feeling through Music â€Å"Music does for feeling what language does for thought† (Bowman, 1998, p. 200). As a musician, I understand the power of music to evoke feelings. Listening to or performing a great work of music in a concert hall may bring tears or chills to the musician in a way that only music is capable. Similarly, students’ emotional lives may be heightened by experiences in the classroom. According to Reimer (2003), the â€Å"emotional dimension of music-its power to make us feel, and to â€Å"know† through feeling-is probably its most important defining characteristic† (p. 72). In Western history, emotion has often been regarded less valuable than intellect (Reimer, 2003). Some people do not consider the arts to be as important as other core subjects such as math and reading in education due to the belief that arts are based on emotions and not reasoning or intellect. Recently, however, scientific scholars have begun to recognize that human intelligence, or cognition, is exhibited in a variety of forms, directly related to functions of the body, and tied to feeling. Dimensions of the mind, once thought to be separate and unrelated, are now known to work together, contributing to the things we know and experience. Anthony Damasio, a research neurologist, believes â€Å"feeling is likely to be the key factor in human consciousness itself and an essential ingredient in human cognition† (Reimer, 2003, p. 76). The capacity to feel â€Å"pervades and directs all we undergo as living, aware creatures† (p. 8). â€Å"Direct experiences of feeling are embodied in music and made available to the bodied experience of those engaged with it† (p. 80). The use of descriptive and symbolic language in the classroom, in the teaching of a varied repertoire of expressive music, aids in drawing out these responses of feeling from students. Including music that is heavy and loud or delicate and light will bring out an array of feelings. I believe students should be given an opportunity to articulate these feelings through journaling and in-class discussion.

Imperialism from 1700 to 1900 Essay Example for Free

Imperialism from 1700 to 1900 Essay From 1700 to 1900, the world was expanding. Many countries took on a expansionism type known as imperialism. Countries such as England used the British East India Company to conquer parts of Asia. America used imperialism to spread their rule westward, known as Manifest Destiny. They both used this tactic as migration. During these encounters, many factors stayed the same, but also differed in some ways. In the 19th century, the Americas were finally free of British control, and decided to spread their nation westward, past the Appalachian mountains to the pacific ocean. These people who traveled were called pioneers, exploring the frontier of America. Along the way, they came across Native American civilizations and tribes. Although the Native Americans were welcoming, the pioneers took advantage of them, through their resources. They eventually lead to the endangerment of the buffalo. They depleted many other of their resources, which caused the Native Americans and pioneers to attack one another. Battles such as Little Bighorn and the Wounded Knee massacre are just two known ones. The pioneers ended up killing off many of the natives, which was known as the French and Indian war, and although many Native Americans still survived those attacks, to this day most of them are force to live on reservations. The Americans then started giving away land in the midwest, that used to be owned by these tribes. The Homestead Act encouraged people to go out west and take land given by the government. The land was typically 100 plus acres. The British initially entered India in the 18th century with the East India Company with the sole thought of its trading and financial benefits. By the beginning of the 19th century, however, ulterior motives started to appear. The British were, technically, the ruling governors of India, but before then, had only been concerned with making money. Now, however, the British began trying to expand their territory and the idea of responsible trusteeship came about. The British, along their conquests, destroyed much of Indian culture and replaced it with their own. The British did however, like the idea of the caste system in separating the people, and so let that remain in tack to remain in control of the population. India became a major trade hub in Asia due to this. British rule also modernized India, bring new  technologies and such there, known as cultural diffusion. And so, the Natives had to stay on their reservations while America expanded. America continued their idea of Manifest Destiny all the way to the Pacific. As for the British, the Indian culture was destroyed and changed to the British way of life.

Case Study Of High Strength Concrete Construction Essay

Case Study Of High Strength Concrete Construction Essay In the text below I have tried my best and put in all of my efforts to create a document that might help other students even without any prior knowledge of the subject to understand the very important subject concrete with thorough understanding of the concrete. The text gives the basic knowledge of the lesser important concepts and has been written to depth for important and practical concepts. I have tried to create a document that shall be used to give lectures and cover the gap between a professor with in depth knowledge of the subject and a student who has just been introduced to the subject. I am also thankful to my professors and friends for their support in completing this work. I hope the document acts as a mode of information rather than being a jigsaw puzzle and fulfill all the requirements for the formal submission. Introduction: Civil engineering is the oldest and the most basic streams of engineering. When we think of civil engineering the first thing that comes to mind is cement and construction, when we come down to the more uses of civil engineering we think of concrete. Concrete is not such a simple thing as it may look down to a non construction related person, it is due to the fact that it has so many practical uses, more than any construction material that it has a specialization of its own. So the study of concrete is very helpful or may be considered the most necessary studies for a civil engineer. Nowadays the study of concrete is considered as the backbone of the construction industry. This subject has its own specializations available for study is such a vast subject that for a construction industry or company the success is decided by its concrete engineers. The modern industry of the todayà ¢Ãƒ ¢Ã¢â‚¬Å¡Ã‚ ¬Ãƒ ¢Ã¢â‚¬Å¾Ã‚ ¢s world relies completely on the construction of concrete structures. Concrete has experienced this great variety of use due to its marvelous properties that completely distinguish it from any of the rest of construction materials. The history of construction traces back to the times of Assyrians and Babylonians who first made the use of clay as a cementing material. The ancient forts and military buildings, the defense structures have witnessed a wide use of the concrete made of aggregates and lime as a binder. Construction of the pyramids in Egypt has also proved the use of lime and gypsum as a binder in the concrete works. The prominent scientists of the concrete study are Vitruvius who is believed to have the knowledge of chemistry of the cementitious lime. One of the remarkable ancient works is the pantheon, which consists of a dome spanning 43.43m and is made entirely of concrete. The Romans also used suitable cements made of suitable limestone burned in kiln or were mixtures of lime and puzzolanic materials (volcanic, ash, tuff) co mbining into a hard concrete. Vitruviusà ¢Ãƒ ¢Ã¢â‚¬Å¡Ã‚ ¬Ãƒ ¢Ã¢â‚¬Å¾Ã‚ ¢s work was followed by the researches made by M. Vicat of France. Joseph Aspedin of Yorkshire (U.K.) was the first to introduce Portland cement in 1824 formed by heating a mixture of limestone and finely divided clay in a furnace to a temperature high enough to drive off the carbonic acid gas. In 1845, Issac C. Johnson invented the cement by increasing the temperature at which the mixture of limestone and clay were burned to form clinker. This cement was the prototype of the modern Portland cement. From then onwards, a gradual improvement in the properties and qualities of cement has been made possible by researchers in U.S.A., U.K., France and Germany. What exactly is concrete: Concrete is a composite man-made material most widely used building material in the construction industry. It consists of a rationally chosen mixture of binding material such as lime or cement, well graded fine and coarse aggregates, water and admixtures (to produce concrete with special properties). In a concrete mix, cement and water form a paste or matrix which in addition to filling the voids of the fine aggregate, coats the surface of fine and coarse aggregates and binds them together. The matrix is usually 22-34% of the total volume. Freshly mixed concrete before set is known as wet or green concrete whereas after setting and hardening it is known as set or hardened concrete. The moulded concrete mix after sufficient curing becomes hard like stone due to chemical action between the water and binding material. It would be impossible to discuss all the aspects of this material in few pages and the discussion is confined to the general characteristics an d quality tests necessary for its use by civil engineers and architects. Most of the ancient structures and historical buildings had been constructed with lime concrete. With the advent of cement, the use of lime concrete has been confined to making bases for concrete foundations and roof terracing. The major factors responsible for wide usage of cement-concrete are mouldability, early hardening, high early compressive strength, development of desired properties with admixtures to be used in adverse situations, suitability for guniting, pumpability and durability. The simple reason for its extensive use in the construction of almost all civil engineering works is that the properties can be controlled within a wide range by using appropriate ingredients and by special mechanical, physical and chemical processing techniques Buildingsà ¢Ãƒ ¢Ã¢â‚¬Å¡Ã‚ ¬from single storey to multistorey, bridges, piers, dams, weirs, retaining walls, liquid retaining structures, reservoirs chimneys, bins, silos, runways, pavements, shells, arches, railway sleepers are but a fe w examples of cement concrete applications. Concept of high strength concrete: Concrete due to its versatile properties is used for many heavy and medium or low cost constructions. So the concrete used in these works is not entirely same. Thus for more important and demanding works a concrete with higher strength is needed. This concrete can be given extra strength by various methods. Usually any concrete which falls in a grade over M65 is considered or called high strength concrete. This M65 signifies a compressive strength of 65N/mm2 after 28 days. This strength apart from other methods can be reached by REINFORCING the concrete with other materials of higher strength. Reinforcing means the mixing the concrete mix with other materials. The materials most commonly used are steel, bamboo, wire mesh, sticks etc. These materials provide those properties to the concrete that the concrete itself lacks. The concrete so reinforced becomes so strong that no other material can be compared to it. Also the strength to cost ratio of this is very less as compared to any other material available in the market. RCC and concrete: RCC and concrete are the same thing but for the fact that RCC has some reinforcement provided to the mix and the plain concrete is just a mix of cement sand and water along with aggregates. The reinforcement is placed where the structure has to be built and concrete is later put on it and both of these bond together to form a high strength concrete. The most common reinforcing material used is steel in the form of steel bars and wire mesh. So the wire mesh or the steel bars are easy to place and the main work then lies in properly preparing the concrete mix. So we shall now study the preparation of the concrete mix. Preparation of concrete: The concrete is fairly easy to manufacture. The preparation of concrete is a stepwise process. Its preparation involves storage of materials namely sand aggregate, cement, water. After that follows batching of materials which is a process of measurement of materials by different, convenient methods. Then falls the process of mixing which is a vital process; the most of properties depend on the mixing conditions and the type of mixing done. Mixing is the process of mixing the materials, batched before and preparing the final concrete mix or paste. The concrete so prepared is now needs to be transported to the site of use. This is done by using pans, wheel bar rows, transit mixers, chutes, bell conveyers, pumps, tower crane and hoists etc. Now that the concrete has been brought to the site it needs to be placed such that it gains maximum strength as easily as possible. So the placing is also a very vital process of the concreting operation. Now that the concre te has been placed we now have to make sure that no voids are left in the placed mix. Compacting the concrete mix makes sure that the concrete gains fullest of its strength. Then remains finishing of the concrete work done to make sure that it looks good aesthetically. Then the concrete needs to be cured to check the development of cracks and control the heat of hydration. The details of each of these processes are as follows: Storing of materials: Storing of materials is controlled so that the materials do not get deteriorated. The materials stored on sites are cement, aggregate, sand, water, steel and any other admixtures. The cement should be stored very carefully as the cement is the second most costly material after steel which is used in lesser quantities; cement easily attracts any moisture in the air and hardens and gets useless for the construction purpose. The cement should be stored in air tight rooms free of moisture and rodents. The bags of cement should be placed at least 30 cm apart from the walls and at least 20 cm above the floor level this is done by making a temporary platform of wood or other cheap material. The cement bags should be placed one over other to a maximum height of 1.5m. The cement bags should be used on the first in first out basis. These bags should be kept covered at all times with a suitable plastic cover. Then comes the aggregates, the aggregates should be so stored that these are distinguishly stored according to their size. These should either be kept completely moist or completely dry this helps to better understand the water cement ratio and provides a strict control over this vital ratio. Then comes sand, sand does not need much special attention while storing but sand so stored should be checked regularly for increase in the moisture content and hence bulking. The water used for adding to the cement or concrete is usually potable water and the water should be kept clean and free of any vegetation and any kind of visible materials and sand etc. Batching: The batching of materials is a simple process of measuring the quantity of the materials to be used for the concrete mix. This is done by two methods namely by weight and by volume. The materials while mixing need to be proportioned properly so that the desired strength and properties can be achieved. This has to be done strictly to ensure the desired properties. In the former category all of the ingredients are measured by weight. But this system has a drawback that the moisture content alters the weight of the materials and this has to be adjusted after experiments and mathematical calculations. The later uses the measuring the materials by volume and is less preferable to the above method. This is for the reason that the sand content varies greatly in volume by the moisture content. This variation is harder to account for accurate measurement. Mixing: The process of mixing of various ingredients of concrete in specified proportion is termed as mixing of concrete. Objectives of mixing: the quality and strength of concrete depends upon proper mixing. The object of mixing is to coat the surface all aggregate particles with cement paste and to obtain concrete of uniform color and required consistency. Methods of mixing: Hand mixing: the process of mixing the ingredients of concrete by manual labor is called hand mixing. It is adopted for small and unimportant and where quantity of concrete used is small. Hand mixing method requires more cement (10%) than machine mixing for obtaining the same strength of concrete. Machine mixing: The process of mixing the ingredients of concrete by a machine is called machine mixing. In case where a large quantity of concrete is to be produced, hand mixing becomes costly even if the labor is cheap. The machine maxing becomes essential. The concrete can thus be produced at a faster rate and at lesser cost. The quality of concrete by machine mixing is also better. Transportation of concrete: The process of carrying concrete mix from the place of mixing to the final position of deposition is called transportation of concrete. Transportation of concrete mix is very important because in transportation, time factor is involved. The mix has to be transported as soon as possible. Precautions in transportation: concrete should be transported as quickly as possible to the formwork within the initial setting time of cement. Efforts should be made to prevent segregation. Transportation cost should be as low as possible. The concrete mix should be protected from drying in hot weather and from rain during transportation. No water should be lost from the mix during transportation. Methods of transportation: -The following are the modes of transportation of concrete: Pans- in this method concrete is transported in iron pans manually. Wheel barrows- steel wheel barrows with 70L capacity with pneumatic tires are used for moderate distances. Truck mixers or tipping lorries- this is used for longer distances of travel. In this a truck or lorry having a mixer built into it is used to carry concrete. Other methods are: Chutes Belt conveyers Tower cranes Pumps Formwork: The temporary construction used as a mould for the structure for the structure in which the concrete is placed and in which it hardens is called formwork or shuttering. It includes all the surfaces in contact with concrete and all necessary supporting members. The part of formwork which consists of sheeting and its immediate supporting or stiffening members is called form. The part of formwork which supports the forms usually for a large structure is called false work. It is yet another important process for concreting. Compaction: Compaction of concrete is a process of eliminating the entrapped air in concrete and achieving maximum density. The importance should not be under estimated. The strength of concrete is reduced by about 40% by presence of only 5% voids. The compaction reduces voids to a minimum. The compaction is done by doing external work on the concrete. Finishing: finishing may be defined as the process adopted for obtaining a true, uniform concrete surface. The importance of finishing is inevitable. It is to keep the concrete surfaces free from undulations. The vibrating or hand tamping of a concrete leaves a slightly rough surface. Finishing of concrete surface is therefore important. The choice of concrete finishing depends upon the ultimate use of the component and desired aesthetic effect. Curing: The process off keeping the concrete moist to enable it to gain strength is called curing. It is name given to procedure used for prompting the hydration of cement. The concrete hardens because of hydration i.e. the chemical reaction between water and cement. This reaction depends on the presence of water. Although there is sufficient water at the time of mixing yet it is necessary to ensure that the water is retained to enable the chemical reaction to continue. Methods of curing: The various methods of curing are Shading of concrete work. Covering the concrete surface with gunny bags or hessians. Sprinkling of water. Ponding method. Membrane curing. Steam curing. Of these, ponding covering of concrete surface with gunny bags or hessians are the most commonly and very widely used. Proportioning of concrete mixes: Proportioning of a concrete mix means determining the relative amounts of materials required for batches of concrete of required strength. This process is generally called as design of mix. In proportioning a concrete mix, one has to choose suitable proportions of all the ingredients of concrete i.e. cement, aggregate and water so as to give concrete its desired properties both on the plastic as well as in hardened stage with the maximum economy. Grades of concrete: concrete id graded according to its compressive strength. As per IS 456:2000 the concrete mixes are designated into fifteen grades. The various grades of concrete are given in the table below: Group Designation Compressive Strength (N/mm2) Ordinary concrete M10 10 M15 15 M20 20 M25 25 Standard concrete M30 30 M35 35 M40 40 M45 45 M50 50 M55 55 M60 60 High strength concrete M65 65 M70 70 M75 75 M80 80 Concretes of compressive strength lesser than 20MPa may be used for lean concrete bases and simple foundations for masonry walls. Grades lower than M20 should not be used in reinforced concrete works. Grades lower than M30 should not be used in post tensioned prestressed concrete. Grades lower than M40 should not be used in pre tensioned prestressed concrete. There are two types of concretes based on the method of proportioning: Ordinary concrete (normal mix concrete) Controlled concrete (design mix concrete) Ordinary concrete (normal mix concrete): The concrete in which the proportions of cement, aggregates and water are determined by adopting nominal concrete mixes and no preliminary tests are performed is called ordinary concrete. It is only used when it is not possible to use controlled concrete. It may be used for grades M20 or lower if designed mix concrete cannot be used for some reasons. The proportions of the ingredients are specified by the engineer usually without testing the materials. There is no guarantee that a M20 nominal mix with adopted proportions (say 1:4:8) will have a 28 days cube strength of 20N/mm2. IS 456:2000 suggests the proportions of materials required for nominal mix concrete as shown in the table below: Grade of concrete Total quantity of dry aggregate per 50 kg of cement (kg) Proportions of fine aggregate to coarse aggregate by wt. Maximum quantity of water per 50kg of cement (liters) M10 480 Generally 1:2 but upper 34 M15 330 Limit is 1:1.5 and lower 32 M20 250 Limit is 1:1.25 30 Controlled concrete (design mix concrete): The concrete in which the proportions of cement, aggregate and water are determined by conducting preliminary tests for the design of mix is called controlled concrete. A design mix concrete is preferred over a nominal mix concrete for durability, strength and economy. Reinforced cement concrete: RCC or reinforced concrete cement is yet another type of high strength concrete. As explained when reinforcing materials of higher strength are added to the concrete it becomes reinforced cement concrete. The main feature of adding this reinforcement is that it makes the concrete very strong even in tension; otherwise in which concrete is very weak. This happens due to the bonding between reinforcing materials and the concrete mix. The concrete so prepared is used for many purposes such as piers, bridges, flyovers, dams, slabs, arches etc. The strength of same proportions of materials of concrete when reinforced yields more than twice the strength as it would otherwise. IS codes help us design structures of RCC by considering various norms and limits of safety and other factors. These tell us what extra provisions are needed to be made in certain conditions. The normally used reinforcements are steel bars which are explained in detail as under: Steel bars are available in the market in various sizes which are the measure of the diameter of the bar. These sizes range from 6 mm to 24 mm for general purpose. Other larger and specialized sizes are also available for special constructions. These bars are cast of steel formed by addition of about 1% of carbon content to iron while ità ¢Ãƒ ¢Ã¢â‚¬Å¡Ã‚ ¬Ãƒ ¢Ã¢â‚¬Å¾Ã‚ ¢s manufacturing. This steel is very hard and is very ductile. Traces of other materials are also added to this steel to modify suitable properties. These bars are of two types based on the process of manufacturing or final properties: TMT- thermo mechanically treated bars Sal- ordinary ribbed bars. TMT: this is a product of the new age and has evolved as a result of scientific research over the years in the fields of metallurgy and other related field such as metallurgy and the properties of metals. These bars as the name suggests are mechanically treated to make stronger. These are first heated to a temp of 1400C (red hot) and then cooled suddenly which makes it stronger. Then these bars are also ribbed which makes them stronger at bonding. These bars are available in the market and are preferred over the other plain or ribbed or SAL bars. SAL: these are the traditional bars which were first tested by forming corrugations or ribs. The ribs on these are helical in shape. These are less strong than the other types of bars (TMT). These bars are manufactured from steel with 0.8-1.2% of carbon content in iron. These bars are brittle and less ductile. So these are nowadays moving out of market. These are not used in any of the engineering works. The cost of these is not considerably less than the TMT bars. These bars are available in sizes ranging from 8mm to 26mm. these bars make a weaker bond than TMT and should not be used for any important works. Design of RCC: RCC structures need quite a lot of mathematical analysis to be done before the values of final construction are received. The maximum amount of steel that can be added to the structures is 4% of the cross sectional area. The slabs and beams designed of RCC are categorized into two parts- singly reinforced structures and doubly reinforced structures. Singly reinforced structures are those in which the steel reinforcement is added to the lower side of the beam or the slab that bears tension. Doubly reinforced structures are those in which the steel reinforcement is added to both- upper and lower side of the structure for cases of variable tension and compression values; or extra strength is required for higher load values or when the dimensions of the member to be cast are limited due to some reason or other. These kinds of things make the RCC structures backbone of the construction industry. These RCC structures with steel are also very safe for shear and torsional forces too. Alterations of properties of concrete (Admixtures): The concrete has its certain properties that sometimes are needed to be changed, for this reasons other materials other than the basic ingredients are added to the concrete while mixing. These materials are called admixtures. These are categorized into several divisions: Accelerators Retarders Water-reducing admixtures Air-entraining admixtures Plasticizers Some common examples of admixtures are fly ashes, silica fume, rice husk ash, metakaolin. Now details of these types of admixtures Accelerators: Accelerators are the chemicals used to accelerate the setting and hardening of concrete. Accelerators are added to concrete to: Increase the rate of hydration and hence to increase the rate of strength development. Reduce the setting time. E.g. of accelerators- calcium chloride, triethenolamine etc. Retarding admixtures (Retarders): Retarders are the chemicals used to delay the setting and hardening of concrete. Retarders slow down the chemical process of hydration so that concrete remains plastic and workable for a longer time than a concrete without retarder. E.g. of retarders are sugar, calcium sulphate, skimmed milk, ammonium chloride, calcium borate, calcium tartarate, mucic acid etc. Water reducing admixtures: These are used to: Increase the workability of freshly mixed concrete without increasing water cement ratio. Maintain workability with reduced water cement ratio. Sugar in addition to acting as a retarder, improves the workability of concrete also. Carbohydrates and organic acids are other examples of water reducing admixtures. Air entraining agents: Air-entraining admixtures are used to entrain air in form of very small disconnected air bubbles in concrete. The air bubbles (approximately .01 to.25mm dia) act as flexible ball bearings and modify the properties of plastic concrete. It also modifies the properties of hardened concrete. Plasticizers: Plasticizing admixture is a substance which imparts very high workability with a large decrease in water content (at least 20%) for a given workability. It also permits the use of lower water cement ratio for the same workability. Materials used as plasticizers: Anionic substances such as lignosulphonates. Nonionic surfactants such as hydroxylated carboxylic acid. Other products such as carbohydrates. Calcium, sodium, and ammonium lignosulphonates are mostly used as plasticizers. Plasticizers are used in the amount of 0.1 to 4% by weight of cement. A 0.5% concentration of plasticizer by weight of cement can: Increase the 28 days compressive strength by 30% with 20% reduction in water cement ratio. Increase slump from 25 to 100mm. Require 15% less cement. Uses: these can be used where a high degree of workability is required in situations like: Deep beams. Column and beam junctions. Tremie concrete. Pumping of concrete. Thin walls of water retaining structures with high percentage of steel reinforcement. This was it about the case study of high strength concrete. I have tried my best to give the best approach possible to every aspect of any concept. Still humans will keep making mistakes so that they can learn from them. Thanks.