Post-Tensioned Concrete Floors Design Handbook

Concrete Wikipedia. Exterior of the Roman. Pantheon, finished 1. AD, still the largest unreinforced concrete dome in the world. Interior of the Pantheon dome, seen from beneath. The concrete for the coffered dome was laid on moulds, probably mounted on temporary scaffolding. Opus caementicium exposed in a characteristic Roman arch. In contrast to modern concrete structures, the concrete used in Roman buildings was usually covered with brick or stone. Concrete is a composite material composed of coarse aggregate bonded together with a fluid cement that hardens over time. Post-Tensioned Concrete Floors Design Handbook' title='Post-Tensioned Concrete Floors Design Handbook' />Most concretes used are lime based concretes such as Portland cement concrete or concretes made with other hydraulic cements, such as ciment fondu. However, asphalt concrete, which is frequently used for road surfaces, is also a type of concrete, where the cement material is bitumen, and polymer concretes are sometimes used where the cementing material is a polymer. When aggregate is mixed together with dry Portland cement and water, the mixture forms a fluid slurry that is easily poured and molded into shape. The cement reacts chemically with the water and other ingredients to form a hard matrix that binds the materials together into a durable stone like material that has many uses. Often, additives such as pozzolans or superplasticizers are included in the mixture to improve the physical properties of the wet mix or the finished material. Most concrete is poured with reinforcing materials such as rebar embedded to provide tensile strength, yielding reinforced concrete. Famous concrete structures include the Hoover Dam, the Panama Canal, and the Roman Pantheon. The earliest large scale users of concrete technology were the ancient Romans, and concrete was widely used in the Roman Empire. The Colosseum in Rome was built largely of concrete, and the concrete dome of the Pantheon is the worlds largest unreinforced concrete dome. Today, large concrete structures for example, dams and multi storey car parks are usually made with reinforced concrete. After the Roman Empire collapsed, use of concrete became rare until the technology was redeveloped in the mid 1. Today, concrete is the most widely used human made material measured by tonnage. EtymologyeditThe word concrete comes from the Latin word concretus meaning compact or condensed,4 the perfect passive participle of concrescere, from con together and crescere to grow. Disable Activation Adobe Cc Mac Full. HistoryeditPrehistoryeditPerhaps the earliest known occurrence of cement was twelve million years ago. A deposit of cement was formed after an occurrence of oil shale located adjacent to a bed of limestone burned due to natural causes. These ancient deposits were investigated in the 1. On a human timescale, small usages of concrete go back for thousands of years. Concrete like materials were used since 6. BC by the Nabataea traders or Bedouins who occupied and controlled a series of oases and developed a small empire in the regions of southern Syria and northern Jordan. They discovered the advantages of hydraulic lime, with some self cementing properties, by 7. BC. They built kilns to supply mortar for the construction of rubble wall houses, concrete floors, and underground waterproof cisterns. The cisterns were kept secret and were one of the reasons the Nabataea were able to thrive in the desert. Some of these structures survive to this day. Classical eraeditIn the Ancient Egyptian and later Roman eras, it was re discovered that adding volcanic ash to the mix allowed it to set underwater. German archaeologist Heinrich Schliemann found concrete floors, which were made of lime and pebbles, in the royal palace of Tiryns, Greece, which dates roughly to 1. BC. 78 Lime mortars were used in Greece, Crete, and Cyprus in 8. Design of Hybrid Concrete Buildings. Contents 1. Introduction 1. Single point of responsibility 1. Design considerations 1. Best practice procurement guidance. International Journal of Engineering Research and Applications IJERA is an open access online peer reviewed international journal that publishes research. Resources include AIA contract documents, handbooks, guidelines, and MasterSpec. S2214399816300170-gr1.jpg' alt='Post-Tensioned Concrete Floors Design Handbook' title='Post-Tensioned Concrete Floors Design Handbook' />Retrouvez toutes les discothque Marseille et se retrouver dans les plus grandes soires en discothque Marseille. BC. The Assyrian Jerwan Aqueduct 6. BC made use of waterproof concrete. Concrete was used for construction in many ancient structures. The Romans used concrete extensively from 3. BC to 4. 76 AD, a span of more than seven hundred years. During the Roman Empire, Roman concrete or opus caementicium was made from quicklime, pozzolana and an aggregate of pumice. Its widespread use in many Roman structures, a key event in the history of architecture termed the Roman Architectural Revolution, freed Roman construction from the restrictions of stone and brick material and allowed for revolutionary new designs in terms of both structural complexity and dimension. Concrete, as the Romans knew it, was a new and revolutionary material. Laid in the shape of arches, vaults and domes, it quickly hardened into a rigid mass, free from many of the internal thrusts and strains that troubled the builders of similar structures in stone or brick. Modern tests show that opus caementicium had as much compressive strength as modern Portland cement concrete ca. MPa 2,8. 00 psi. 1. However, due to the absence of reinforcement, its tensile strength was far lower than modern reinforced concrete, and its mode of application was also different 1. Modern structural concrete differs from Roman concrete in two important details. First, its mix consistency is fluid and homogeneous, allowing it to be poured into forms rather than requiring hand layering together with the placement of aggregate, which, in Roman practice, often consisted of rubble. Second, integral reinforcing steel gives modern concrete assemblies great strength in tension, whereas Roman concrete could depend only upon the strength of the concrete bonding to resist tension. The long term durability of Roman concrete structures has been found to be due to its use of pyroclastic volcanic rock and ash, whereby crystallization of strtlingite and the coalescence of calciumaluminum silicatehydrate cementing binder helped give the concrete a greater degree of fracture resistance even in seismically active environments. Roman concrete is significantly more resistant to erosion by seawater than modern concrete which is also due to the use of pyroclastic materials which react with seawater to form Al tobermorite crystals over time. The widespread use of concrete in many Roman structures ensured that many survive to the present day. The Baths of Caracalla in Rome are just one example. Many Roman aqueducts and bridges such as the magnificent Pont du Gard have masonry cladding on a concrete core, as does the dome of the Pantheon. Middle AgeseditAfter the Roman Empire, the use of burned lime and pozzolana was greatly reduced until the technique was all but forgotten between 5. From the 1. 4th century to the mid 1. The Canal du Midi was built using concrete in 1. Industrial eraeditPerhaps the greatest driver behind the modern use of concrete was Smeatons Tower, the third Eddystone Lighthouse in Devon, England. To create this structure, between 1. British engineer John Smeaton pioneered the use of hydraulic lime in concrete, using pebbles and powdered brick as aggregate. Developed in England in the 1. Portland cement was patented by Joseph Aspdin in 1. Aspdin named it due to its similarity to Portland stone which was quarried on the Isle of Portland in Dorset, England. His son William Aspdin is regarded as the inventor of modern Portland cement due to his developments in the 1. Reinforced concrete was invented in 1. Joseph Monier. 2. In 1. 88. 9 the first concrete reinforced bridge was built, and the first large concrete dams were built in 1. Hoover Dam and Grand Coulee Dam. Composition of concreteeditMany types of concrete are available, distinguished by the proportions of the main ingredients below. In this way or by substitution for the cementitious and aggregate phases, the finished product can be tailored to its application. Strength, density, as well chemical and thermal resistance are variables. Aggregate consists of large chunks of material in a concrete mix, generally a coarse gravel or crushed rocks such as limestone, or granite, along with finer materials such as sand. Economics of R. C. C. Water tank Resting over Firm Ground vis a vis Pre stressed Concrete Water Tank Resting over Firm Ground. By. MS. SNEHAL R. METKARP. G. STUDENTDEPARTMENT OF CIVIL ENGINEERINGSTRUCTURAL ENGINEERING IIND YEARP. R. M. T OF TECH. RESEARCH, BADNERA AMRAVATISANT. GADGE BABA AMARAVATI UNIVERSITY MAHARASHTRACOUNTRY INDIA 4. GUIDED BYProf A. R. MundhadaPROFESSORDEPARTMENT OF CIVIL ENGINEERING,P. R M. I. T. R., BADNERA, AMRAVATI. MAHARASHTRA, INDIA 4. Abstract. Water tanks are used to store water and are designed as crack free structures, to eliminate any leakage. In this paper design of two types of circular water tank resting on ground is presented. Both reinforced concrete RC and prestressed concrete PSC alternatives are considered in the design and are compared considering the total cost of the tank. These water tank are subjected to the same type of capacity and dimensions. As an objective function with the properties of tank that are tank capacity, width length etc. A computer program has been developed for solving numerical examples using the Indian std. Indian Standard Code 4. IS 3. 37. 0 I,II,III,IV IS 1. The paper gives idea for safe design with minimum cost of the tank and give the designer the relationship curve between design variable thus design of tank can be more economical ,reliable and simple. The paper helps in understanding the design philosophy for the safe and economical design of water tank. Keywords. Rigid based water tank, RCC water tank, Prestressed Concrete, design, details, minimum total cost, tank capacity. I. INTRODUCTIONStorage reservoirs and over head tanks are used to store water, liquid petroleum, petroleum products and similar liquids. The force analysis of the reservoirs or tanks is about the same irrespective of the chemical nature of the product. In general there are three kinds of water tanks tanks resting on ground Underground tanks and elevated tanks. Here we are studying only the tanks resting on ground like clear water reservoirs, settling tanks, aeration tanks etc. The wall of these tanks are subjected to pressure and the base is subjected to weight of Water. Advertisements. In this paper, both types of reinforced concrete and prestesses concrete water tanks resting on ground monolithic with the base Are design and their results compared. These tanks are subjected to Same capacity and dimensions. Also a computer program has been developed for solving numerical examples using IS Code 4. IS 1. 34. 3 1. 98. IS 3. 37. 0 Part I,II,III,IV 1. IS Code 1. 34. 3 1. From the analysis it is conclude that for tank having larger capacity greater than 1. ObjectiveTo make the study about the analysis and design of water tank. To make the guidelines for the design of liquid retaining structure According to IS code. To know about design philosophy for safe design of water tank. To develop program for water tank to avoid tedious calculations. To know economical design of waterThis report is to provide guidance in the design and construction of circular priestesses concrete using tendons. Previous Research. From the review of earlier investigations it is found that considerable work has been done on the method of analysis and design of water tanks. Tanetal. 1 1. British Code for water tanks, using a direct search method and the SUMT. The cost function included the material costs of concrete and steel only. The tank wall thickness was idealized with piecewise linear slopes with the maximum thickness at the base. Thakkar and Sridhar Rao 2 1. Indian code. Al Badri 3 2. ACI Code 2. 00. 2. He proved that the minimum cost of the silo increases with increasing of the angle of internal friction between stored materials, the coefficient of friction between stored materials and concrete, and the number of columns supporting hopper. Al Badri 2. 00. AC I Code 2. The cost function included the material costs of concrete, formwork and steel reinforcement. He proved that the minimum total cost of the corbel increases with the increase of the shear span, and decreases with the increase of the friction factor for monolithic construction. Hassan Jasim Mohammed 4 studied the economical design of concrete water Tanks by optimization method. He applied the optimization technique to the structural design of concrete rectangular and circular water tank, considering the total cost of the tank as an objective function with the properties of the tank viz. From the study he concluded that an increased tank capacity leads to increased minimum total cost of the rectangular tank but decreased minimum total cost for the circular tank. The tank floor slab thickness constitutes the minimum total cost for two types of tanks. The minimum cost is more sensitive to changes in tank capacity and floor slab thickness of rectangular tank but in circular type is more sensitive to change in all variables. Increased tank capacity leads to increase in minimum total cost. Increase in water depth in circular tank leads to increase in minimum total cost. Abdul Aziz A. Rashed 5 rationalized the design procedure for reinforced and prestressed concrete tanks so that an applicable Canadian design standard could be developed. The study investigates the concept of partial prestressing in liquid containing structures. The paper also includes experimental and analytical phases of total of eight full scale specimens, representing segments from typical tank walls, subjected to load and leakage tests. In analytical study a computer model that can predict the response of tank wall segments is described and calibrated against the test results. The proposed design procedure addresses the leakage limit state directly. It is applicable for fully prestressed, fully reinforced and partially prestressed concrete water tanks. The conclusions that are drawn are as follows A design method based on limiting the steel stress, does not produce consistent crack or compression zone depths under the application of prestressing nor under a combination of axial load and moment. A design method based on providing a residual compressive stress in concrete dose not utilizes non prestressed reinforcement effectively. Relaxing the residual compressive stress requirement permits a more efficient design. The stresses in non prestresssed steel are higher, but remain below yield under service load. Therefore, less reinforcement is required. Load eccentricity significantly affects the behavior of the prestressed concrete sections. The behavior with a small load eccentricity, less than about half the thickness, the section may be treated as a flexure member. The ratio of non prestressed steel to prestressed steel in partially prestressed concrete section has a significant effect on the member serviceability and strength. Choosing the ratio such that both non prestress and prestressed steel reach their strength simultaneously utilizes both types of steel at the ultimate limit state effectively. Increasing the wall thickness is very effective in increasing the capacity of the section and improving its serviceability by increasing the compression zone depth and reducing the deformations. Chetan Kumar Gautam 6 Highlights the point named Comparison of Circular Reinforced Concrete and Prestressed Concrete Underground Shelter. In his paper, design of two types of large circular underground shelters is presented. The shelters are made of precast concrete sections. Both RC and PSC alternatives are considered in the design and compared. The shelters are subjected to same type of external loadings and support conditions. The study conclude that the feasibility of using the vertical casting process of making the modules of shelters as it is suitable for manufacturing of large diameter pipes. He also suggested that the incorporation of fibers, specially steel fibers improves a host of properties of concrete, including its crack resistance, flexural strength, ductility, etc.