Structural Strengthening Methods

Structural Strengthening Methods INTRODUCTION GENERAL Strengthening or upgrading of a structure may be required quite often due to several reasons. Many a times, loads due to seismic forces or wind forces are not taken into account while designing the structure or sometimes a higher load carrying capacity is required in case the use of the structure changes. In such cases, strengthening of a structure may be required. Strengthening may also be required in case of any deficiency in the ability of a structure to carry the expected design loads. There may be several reasons for such deficiencies in a structure. These include structural damage, loss of concrete section, corrosion of steel rebars, error while construction or flaws in the design. Several techniques can be employed to overcome such problems. Arriving at a best and optimum strengthening solution for each project depends on various factors like increase in strength required, constructability restrictions, size and importance of project, accessibility, time availability, and avai lability of skilled/unskilled labour, availability of raw material and other equipments, environmental conditions, cost or many such other issues. Out of the available strengthening techniques, the most wonderful feature of strengthening by FRP laminates is its non-corrosive nature. It is due to corrosion of rebars that billions of capital of a country is wasted every year. Replacing steel reinforcement by the non-corrosive FRP reinforcement is an effective alternative that obviates the problem of loss of strength of a structural element due to corrosion. Thus, investigation of the behaviour or response of such strengthening techniques is very crucial before it is adopted in actual structures. Experimental based testing has been carried out by researchers for long. This method of investigation is both time-consuming and expensive. Thus, analytical and numerical methods of investigation are in vogue. Finite Element Method (FEM) is one of the numerical methods of analysis. With the advancement in computer and technology, FEM softwares like ANSYS are reliable along with being less time-consuming and cost-effective. In the present research, numerical investigation of RC beams strengthened with FRP laminates is carried out. STRENGTHENING USING FRP COMPOSITES There are several reasons for which strengthening of a structure may be required. And for this purpose several conventional techniques like use of steel plates have been used since ages. But in the recent years, use of Fibre reinforced polymers for structural strengthening has come into existence. Fibre Reinforce Polymers or FRPs exhibit several improved properties, like non-corrosiveness, high stiffness-weight ratio, high strength-weight ratio, high fatigue strength, flexibility and ease of application due to its light weight. In recent years, several researchers have been studying the use of FRP sheets or laminates to strengthen concrete structural members. Using FRPs for strengthening have turned out be an effective technique suitable for several structural elements such as beams, columns, walls, and slab. For strengthening of existing structures externally, FRP materials are considered most suitable as it is non-corrosive, resistant to chemicals and non-magnetic. From the past research, it has been found that Glass Fibre Reinforced Polymers or GFRP is very effective in increasing flexural as well as shear strength of the reinforced concrete structures when bonded externally. FRP laminates is one of the emerging material for strengthening of RC beams. It can be used for strengthening the beams weak in flexure by bonding the laminate at the bottom soffit and for strengthening the beam weak in shear, laminates are bonded to the side faces of the RC beam. But unfortunately, no proper guidelines or provisions are included in the current Indian design codes for strengthening of concrete structural elements with FRP laminates. At the same time, research in recent years focussing on the application of FRP laminates for strengthening of RC structures has led to its increasing application practically. FRP laminates are composite materials that consist of high strength fibres of glass, carbon or aramid in a matrix, where the main load is carried by the fibres. These laminates are plates that may be bonded to the surface by either dry bonding or wet bonding technique. These laminates can be used to strengthen beams and slabs weak in shear or flexure, columns to increase the concrete confinement or even walls to increase the lateral load carrying capacity. MERITS AND DEMERITS OF FIBRE REINFORCED POLYMER COMPOSITES MERITS FRP or Fibre Reinforced Polymers are very efficient in strengthening of reinforced concrete structural elements. They have high ultimate strength and have lower density as compared to that of steel. It is very convenient to handle and transport because of its light weight. Moreover, its flexible nature makes installation process much convenient as compared to installation of heavy steel plates. Another major advantage of using FRP laminates in strengthening of RC structural elements is that it doesn’t require full scaffolding while installation at soffits of bridge. In case of strengthening RC structures by using FRP laminates, no bulky lifting gear is required and there is no requirement of fittings such as bolts that are susceptible to corrosion. Moreover, application of FRP laminates is just as easy as application of wallpapers on wall. Also, there is no risk of damage to the steel reinforcement as no drilling is required for inserting bolts. Nowadays, wet-bonding technique is used which further reduces the risk of debonding of the laminates. Furthermore, another most important advantage in the use of FRP laminates in strengthening of RC structures is that these laminates are available in long lengths and varying widths due to which no joints or laps are required. Application of FRP laminates on irregular surfaces or curved profiles is not a problem due to its flexible nature. If the application of FRP laminates is done carefully by keeping care of proper measures, it proves to be durable. Moreover, it is comparatively convenient to repair by application of another layer. Use of FRP laminates for strengthening of bridges and other important structures like tunnels is very suitable as their light weight and less thickness do not alter the dimensions of the strengthened element or add to the weight of structure. Most important advantage of the use of FRP laminates for strengthening RC structural elements is that it is non-corrosive in nature. Because of the ease in application, it results in saving both the man-power and useful resources. Thus, all these merits in combination results in a significant and effective means of strengthening technique that is much more quicker and simpler as compared to other strengthening techniques like use of steel plates. DEMERITS Along with several advantages of FRP or Fibre Reinforced Polymers, there are few disadvantages that may hinder its application. FRP laminates that are mainly used for external strengthening of structures are susceptible to exposure of external environment. So, in order to protect it from fire or any other accidental damage, proper protection measures are to be adopted. Another major problem occurred in the application of FRP laminates in strengthening of RC structures is delamination or debonding of the laminate. It problem can be overcome by taking proper measures while bonding it with the help of epoxy. Nowadays, even the technique of wet bonding is in practice in order to eliminate such problems. Another major disadvantage that may hinder its application is its high cost. But, after a complete comparison of the total cost and the strengthening achieved with that of other strengthening methods like use of steel plates etc., the application of FRP in strengthening may prove to be economical and more efficient. INTRODUCTION TO FINITE ELEMENT MODELLING/METHOD Finite Element Method or (FEM) is an approximate numerical technique for determining solutions to boundary problems for differential equations. In this method, a stable solution is produced by reducing error function by employing variational method. In this method, a structure or a model to be analyzed is discretized or broken down in number of small sub-domains, and are called elements or finite elements. These elements are connected to one another by points known as nodes. There are many finite element packages available. ANSYS which means Analysis System is a FEM software package which offers engineering simulation solution sets in engineering simulation that a design process requires. Companies in a wide variety of industries use ANSYS software. The tools put a virtual product through a rigorous testing procedure before it becomes a physical object. IMPORTANCE OF FINITE ELEMENT MODELLING It is difficult to model the complex behaviour of reinforced concrete analytically in its non-linear zone. And we know that experimental testing which has been used since ages for the purpose of research work is very time consuming along with being expensive. But with the advancement in computer and technology, and powerful techniques of analysis such as Finite Element Method or FEM, many efforts have been under taken by the investigators to obviate the need for creating multiple models in case of experimental investigation. Thus, finite element approach is gaining popularity not only because it is cost effective and less time consuming, along with this it obviates the need to create multiple models for the purpose of research or investigation, preventing wastage of useful resources. Along with this, it is a powerful tool that allows modeling and analyzing complex non-linear behaviour of RC structures efficiently. Moreover, not only modelling and analyzing, it is also useful in obtai ning the load deflection behavior and crack patterns under various loading conditions. Thus, Numerical investigation or finite element analysis is comparatively much more effective and less complicated than development of analytical models because of the several obvious reasons. OBJECTIVES OF THE WORK The specific objectives of the present investigation are as follows: To numerically investigate the behaviour of RC beams strengthened with FRP laminates using ANSYS To obtain the corresponding load deflection curve of RC beam without FRP and RC beams strengthened with varying configuration of GFRP and CFRP laminates. To draw the comparison between ANSYS results experimental results available in the literature. To study the comparison between the behaviour and the load deflection profile of RC beams strengthened with glass fibre and carbon fibre laminates. SIGNIFICANCE OF THE WORK Experimental testing is one of the most commonly used methods for prediction of the behaviour of reinforced concrete elements till failure. This is both time consuming and costly. Thus, finite element approach is gaining popularity not only because it is cost effective and less time consuming, along with this it obviates the need to create multiple models for the purpose of research or investigation, preventing wastage of useful resources and manpower. In the present investigation, the non-linear response of reinforced concrete (RC) beams strengthened with FRP laminates has been carried out with the intention to investigate the effectiveness of GFRP and CFRP laminates bonded in varying configuration. In this investigation, ANSYS software is used to carry out Finite element modelling of RC beam. A total of nine beams are modelled and analyzed using ANSYS software up to the failure and the load deformation curves are plotted and the cracking behaviour is monitored. Concrete block is modelled by using SOLID65 element while the steel reinforcement is modelled using LINK180 element by using discrete method. While, for modelling of FRP laminates SOLID185 (layered solid) element is used. The result obtained from finite element investigation is then compared with the experimental results in the referred literature (Sandeep G. Sawant, 2013) with respect to load-deflection values, formation of initial crack, failure mode and the ultimate load carrying capacity of the RC beam.

Conservation of Electricity

Electricity is the flow of electrical power or charge. It is a secondary energy source, which means that we get it from the conversion of other sources of energy, like coal, natural gas, oil, nuclear power and other natural sources. The energy sources we use to make electricity can be renewable or non-renewable. Despite, its great importance in our daily lives, most of us rarely stop to think what life would be like if suddenly our world was without electricity!I shudder at the thought. All machines would stop; cities and towns would be into total darkness and panic. The end result would be destructive. Yet, like air and water we tend to take electricity for granted. Our daily lives are completely dominated by electricity, from lighting and cooling our homes to powering our televisions, computers, washers and stoves. Electricity is a controllable and convenient form of energy used in the application of heat, light and power.As responsible home owners and consumers, we should take the initiative to conserve energy. We need to be aware of our options and make our homes energy efficient. There are lots of household appliances with the logo â€Å"Energy Star†, these products can help reduce high energy bills and protect the environment from global warming. We also need to enforce several basic energy saving rules in our homes.Firstly, turn off lights and televisions whenever you leave a room, switch from higher wattage standard light bulbs to lower wattage compact fluorescents light, shut down computers after use because ‘stand by’ mode still uses electricity. Also unplug any battery and cell phone chargers once the units are fully charge. Solar energy is another alternative source of energy. It allows you to produce your own electricity with no noise, no air pollution or moving parts while using a clean renewable resource. So lets make promise that we will conserve electricity.

Lies and Deceit Paper

Lies and Deceit on Animal Farm/ the Real World: Speech There have been many examples of dictatorship across the world. Some examples of these are Hitler of Germany, Castro of Cuba, and Mussolini of Italy; they all have been corrupted by power. Joseph Stalin of communist Russia is the most accurate example because he is like Napoleon. People, especially leaders, use lies and deceit to maintain power; Napoleon is like Stalin because they are both corrupted by power.People often tell lies when it is convenient; the pigs told the other animals many lies some of which include, when the pigs took the milk and apples, when they lied about Boxer’s death, and when they said that the farm would be so much better off without Jones, but everything was just as bad if not worse. People tell lies as simple as trying to protect others’ feelings or something really complicated to try and get out of trouble either way the bottom line is people lie.The first lie of many that the Napoleon and the other pigs told is when Major is saying that Jones the farmer is treating the animals poorly and is trying to convince them to rebel against him. He tells them, â€Å"The life of an animal is misery and slavery; that is just the plain truth† The animals didn’t know that the pigs were just planning to take over and be just as bad as Jones was, or even worse. People tend to lie and deceive others when it is convenient for them, to make it easier on themselves.I’m pretty sure that all of us, at one point or another lied to our parents because it was what seemed easier at the time; For example, a child may lie because they broke something on accident, or a teenager stayed out past curfew and are lying to get out of it. After Old Major’s speech to the animals, Snowball tries to convince Mollie that Jones was bad; she was one of the rare few who liked him. Snowball was being corrupted by power, and he is a very convicing liar which is why Mollie believe s him. Then once the pigs got rid of Jones, they were taking all of the good apples and milk and saying it was for the health of their brains.Humans in the real world lie in their favor if we want something bad enough we will lie to get it. Boxer starts to work himself to death when they build the mill and he works day and night for weeks straight. Napoleon then names the mill after himself even though Boxer and the other animals did all of the work. People also lie or stretch the truth when we want to take credit for an achievement that we may not have even done ourselves. Then Napoleon sold wood to a human without consulting the group which made everyone a little angry.Humans do things without asking first. Squealer lied to the others after that by telling them Boxer was going to the vet instead of the knackers. â€Å"The van had been previously owned by the knackers and then bought by a vet and they have not yet re-painted the van† He said. When it was all said and done an d the transformation was complete one dictator was switched for another the animals were in the same place they had previously been. Napoleon would stand on his hind legs and even carry around a whip with him to keep the others in line.Then he tried to lie and say that the humans aren’t so bad after all. Nothing could have been further from the truth. In chapter three, the pigs’ deceit the other animals into thinking everything was okay when in fact it most definitely was not. The pigs were so clever that they could think of a way out of any and every difficulty. To recapitulate, people lie all the time and it is similar to the book because the pigs told the others the milk and apples were just a sacrifice, that Boxer’s death was an unfortunate accident, and that the pigs didn’t help anything.As a consequence the farm was worse then before, Boxer and many of the animals were killed, the mill was torn down and the pigs took over and made everything worse. Telling the truth may be worse at first, but in the long run it is the better decision. ————————————————- ————————————————- ————————————————- ————————————————- Top of Form Powered by Bottom of Form

Should Touring The Canon City Prisons Essay - 1947 Words

While touring the Canon City Prisons, I already knew the basis of my thesis and so paid special attention to the recreational programs within the prisons and the inmates that were involved. The research that I gathered outside of my tour also added to the insight on if these programs were effective as well as more information on what I wasn’t able to observe. Sports and Rehabilitation In both the minimum and medium security level prisons, there was a designated outside rec area with exercise equipment such as weights, sports balls, basketball hoops etc. The inmates in the Arrowhead facility had free range of the outdoor area with a full track, small fields, a basketball court and weight-lifting area which were mostly all in use during that section of the tour. This environment seemed relaxed and a comfortable outdoor area, especially compared to the Territorial facility. There, the rec area was a much smaller space, with a high population inside that was surrounded by a metal fence producing a more stressful and restricted outdoor environment. When considering outside research on this topic, the minimum security facility had clear sufficient resources for optimum results on all types of sports and athletics, which is known to create more positive mental, physical and social outcomes for both the inmates and officers (Gallant 2015). Althou gh the medium security facility did have an outdoor area, there was no sign of potential organized sports with only minimalShow MoreRelatedExploring Corporate Strategy - Case164366 Words   |  658 Pagespractice. They are not intended to be a comprehensive collection of teaching material. They have been chosen (or speciï ¬ cally written) to provide readers with a core of cases which, together, cover most of the main issues in the text. As such, they should provide a useful backbone to a programme of study but could sensibly be supplemented by other material. We have provided a mixture of longer and shorter cases to increase the ï ¬â€šexibility for teachers. Combined with the illustrations and the short caseRead MoreManagement Course: Mba−10 General Management215330 Words   |  862 Pagesaffect a broad range of decisions, including the following: ââ€"  ââ€"  ââ€"  ââ€"  ââ€"  ââ€"  ââ€"  How to invest in technology How to lead meaningful human resources initiatives How to maintain alliances successfully What the speed of new product or service development should be What the appropriate time horizons for investments and financial planning are How to implement productive cost reduction How to recognize when regular audits of quality compliance will not guarantee customer loyalty Businesses are growing more