Conventional concrete structures are reinforced with non prestressed and prestressed steel. The steel is initially protected against corrosion by the alkalinity of the concrete, usually resulting in durable and serviceable construction. For many structures subjected to aggressive environments, such as marine structures and bridges and parking garages exposed to deicing salts, combinations of moisture, temperature, and chlorides reduce the alkalinity of the concrete and result in the corrosion of reinforcing and prestressing steel.
The corrosion process ultimately causes concrete deterioration and loss of serviceability. To address corrosion problems, professionals have turned to alternative metallic reinforcement, such as epoxy-coated steel
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Furthermore, FRP materials do not exhibit yielding; rather, they are elastic failure. So efforts are being made to establish recommendations for design with FRP reinforcement. 1.2 HISTORY OF FRP REINFORCEMENT:
FRP composites are the latest version of the very old idea of making better composite material by combining two different materials that can be traced back to the use of straw as reinforcement in bricks used by ancient civilizations. FRP reinforcement can be found in the expanded use of composites after World War II.
GFRP bars were considered a viable alternative to steel as reinforcement for polymer concrete due to the incompatibility of thermal expansion characteristics between polymer concrete and steel. In the late 1970s, The 1980s market demanded nonmetallic reinforcement for specific advanced technology; the largest demand for electrically nonconductive reinforcement was in facilities for MRI (Magnetic Resonance Imager) medical equipment.
FRP reinforcement became the standard in this type of construction. Other uses developed as the advantages of FRP reinforcement became better known and desired, specifically in seawall construction, substation reactor bases, airport runways, and electronics
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Unlike steel bars, some FRP bars exhibit a substantial effect of cross-sectional area on tensile strength. For example, GFRP bars from three different manufacturers show tensile strength reductions of up to 40% as the diameter increases proportionally from 0.375 to 0.875 in. (9.5 to 22.2 mm On the other hand, similar cross-section changes do not seem to affect the strength of twisted CFRP strands The sensitivity of AFRP bars to cross-section size has been shown to vary from one commercial product to
We use metals to construct all kinds of structures, from bridges to skyscrapers to elevators. The strength as well as durability of materials that are crafted out of metal make the materials ideal not only for construction but also for many other applications.
(1) The development of carbon-embedded plastics, otherwise called “composits,” is an important new technology because (2) it holds the key for new aircraft and spacecraft designs. This is so because (3) these composits are not only stronger than steel but lighter than aluminum.
The failure of beam-to-column connections in steel Special Moment Resisting Frames had the most to do with most of the damage in these buildings. In response to the pattern of buildings including SMRF's, there have been studies to improve the design and construction practices to allow for better and more improved buildings. The higher building codes wanted engineers to find new ways to allow homes, apartments or skyscrapers the ability to sustain a powerful earthquake. These engineers borrowed the model from New Zealand engineer Bill Robinson. His method was to use lead-rubber bearings, which minimize the vibrations caused by the earthquake, improving its performance during seismic activity. Many of the old buildings that took damage during the earthquake had to be retrofitted. This was done by either infilling the walls, adding braces, adding buttresses, adding new frames, exterior or interior, completely rebuilding or isolating the building. All of these techniques of retrofitting a building all add extra support to the remainder of the building. Most of the residential structures that took damage and were deemed uninhabitable were the apartments or condominiums that were made of light, wood frames. Also, many houses made using stucco took extensive damages. This was due to the fact that the stucco was not properly installed in the first place,
Yu-Fei Wu, Tao Liu, and Leiming Wang (2008). “Experimental Investigation on Seismic Retrofitting of Square RC Columns by Carbon FRP Sheet Confinement Combined with Transverse Short Glass FRP Bars in Bored Holes.” J. Compos. Constr.,ASCE.12, 53-60.
Because of the existence of some misunderstanding between the concrete manufacturer and the architect/design team, in regards to which party should take the responsibilities to implement the water proofing details and installation. Since the Elliot Lake Inquiry has not come to a conclusion of that matter (Dec.16th, 2013), the responsibility of the waterproofing detailing is not yet clear. These leaks allowed water to penetrate through the topping and let the iron access the frame of the building. Until then, the corroded building’s frame getting worse and yet the roof top parking deck allowed water to penetrate the building until three decades. The corrosion that eventually so severe leads to the failure of the weld on a connection, resulting in the collapse.
There are two major requirements when picking environmentally preferable products. The first requirement comes in local production area and mandates the use of “products that were extracted, processed, and manufactured locally for the following components; framing, aggregate for concrete and foundation, drywall or interior sheathing” (U.S Green Building Council). These goods are required to contain 90% of the EPP product being substituted. The second requirement, quite like the first consists of different materials...
For its realization, it was required to construct two cantilever thick concrete sections hanging from each abutment. In this case, two deficiencies with regard to reinforcement design were identified: improper detailing of rebars and absence of shear reinforcement in the middle of the concrete section, the later though was not required by the code of practice at that time. Therefore, improper detailing that caused the concentration of numerous bars in the same plane created a plane of weakness, which any cracks developing from it couldn’t be intercepted due to the absence of any shear reinforcement bars in the middle of the concrete slab. As a result, the bridge lost its ductility and was destined to a sudden crushing failure that prohibited any precautionary measures. (Johnson G. ,
Strasky, J. (2004). Recent development in design of stress ribbon bridges. Retrieved from http://docs.google.com/viewer?a=v&q=cache:HZ_0RHziXHQJ:www.cement.org/Bookstore/download.asp%3Fmediatypeid%3D1%26id%3D7121%26itemid%3DIS617+stress+ribbon&hl=en&gl=us&pid=bl&srcid=ADGEEShElFbAnAHmbhR0Xr7oSO5RWxWd7CKzAA-IJAUKW3xsI0niIoTDH_BowhTg6N-rYhBlJ39EpWH4oEH2h9y4KY3_ekYc EY0lXD8K-Xrva1vl4yqAM58jGNMkI03-vCCCVe8RvYR5&sig=AHIEtbR6ZvE Amub84QgS4uUL-H1s-o0lbQ
Carbon-fiber-reinforced-polymer (CFRP) is a composite polymer made up of carbon fibers and a binding polymer. The binding polymer can be a thermoset resin or thermoplastic polymer(s). Examples of thermoplastic polymers that can bind with carbon fiber to make CFRP are polyester, nylon, or vinyl ester. A thermoset resin that can combine with the carbon fiber to make CFRP is epoxy. The combination of the carbon fibers and a thermoset resin or thermoplastic polymer producing CFRP results in a light weight fiber-reinforced plastic that is tremendously strong. Depending on the binding polymer, CFPRs have a wide range of applications and are used when a light weight material with high rigidity and strength are required.
Reinforced concrete is stronger than basic concrete. Steel reinforcing bars known as rebar is incorporated in the concrete structure to act together in resisting the force. The steel reinforcing bars absorbs tensile and compression because plain conc...
...n most part if steel were to be used in a Type I structure, it would be to reinforce the concrete because concrete is strong in compressive strength but weak in tensil strength. If there is any exposed steel, it is fire proofed with a fire retardant. Mainly the fire hazards that firefighters have to face in these structures are usually because of human error during the construction of the buildings or when occupants are occupying the building. In a construction sites welding, cutting, plumber’s torches, electrical wiring, and heaters all pose a fire hazard. The other risk of this type of building would be of a collapse of the concrete walls or floors during construction.
16. Francis S. Onderdonk, ‘The ferro-concrete style: reinforced concrete in modern architecture : with four hundred illustrations of European and American ferro-concrete design”, United States, Hennessey + Ingalls, 1998
... about 1 mm to 2mm per year which can be achieved though using multiple methods of corrosion protection. 5 CONCLUSION Overall the costs to a project by using of a combination of corrosion management techniques are much less than having an inadequate corrosion management plan. Corrosion control has in the past been relegated to a last step during design as discussed by Ahmad (2006). Having a wider appreciation of corrosion we can see that many fundamental steps should be taken in design and that there are a number of economical choices that can be made. Appendix 1 and 3 show a corrosion control checklist and passive design considerations. Both types of corrosion control incorporate practices that will increase the serviceable life of a product. Both passive and active corrosion management should be used in a design, building more efficient and more durable structures.
Summary 6 5. How will your use case bring value to IGATE business/vertical 6? References 6 - 7. About the Authors 6 Abstract Polymers popularly coined as “plastics” have proved their importance in different areas like FMCG, pharma, automobiles, etc. Plastics are versatile materials with unique properties like high strength to weight ratio, good aesthetics, good processability, balanced engineering properties and optimum cost led its entry into medical industry.
and resistant to wind, water, rodents and insect. On the other hand, the concrete has some