Posted at 11.25.2018
Concrete technology as a branch self-discipline of technology requires upsurge in the degree of specialty area and loan consolidation of the fiber content materials in the concrete matrix form amalgamated materials. It requires knowledge of the principles related to the conversation between the fibers and adhesive cement, mortar or matrix concrete that impact the creation and nature of the merchandise. The researchers and technicians have been actively exploring to find the materials which will be used as substitution of typical materials that can offer an attribute best new design and advancement to enhance the materials.
The development of dietary fiber technology is in the collection with the development of understanding of the material. Following a popular and technology in applying dietary fiber, the fiber content technology has produced various kinds of fibers potential for commercialization. Participation fibre reinforcement in cement, mortar and cement adhesive work to improve the engineering properties of several based materials such as fracture amount of resistance, bending power and level of resistance to exhaustion, impact, thermal shock or chipping. Consolidation of materials by means of cement mortar or cement is becoming an appeal as a building material because it is inexpensive, gets the resilience and has a compressive durability and tightness sufficient for restructuring. However, the cons can be found on fragile character, tensile durability and impact of the weak as well as receptive to moisture movement. Hence, strengthened by fibers that contain enhanced capabilities give a suitable alternative, practical and inexpensive to overcome having less features of normal concrete or mortar.
Elements of any fiber is a continuous filament in the form of an express term sheet or spreadsheet form. Materials can generally be classified into three types : synthetic fibers, natural materials and mineral fibres. Synthetic materials are man-made fibres. It is based mostly chemicals such as petrochemicals and man made fibers derived typically from nylon, polyster, aerylic polymer and polyacrylonitrile materials used to make fiberglass. Gleam bundle of fibers that produce the polymer chain is really as strong as aramid and string bond size as dyneema.
While natural fiber derived from natural options, from vegetation and animals. Herb materials are cellulose and lignin-based stacks such as egyptian cotton, jute, coir, petrol hand bunches, flax and so forth. It can be from seeds(cotton, kapok), leaf(pineapple, banana), leather plant(jute, kenaf, rattan, hemp), fruit(coconut, palm) and straw(rice, whole wheat, barley, turf). Next, canine fibers derived from protein debris like silk and wool. For mineral fibers, it derived from the earth's crust and it happens naturally. It is based on asbestos fibers(chrysotile, amosite, crocidolite, tremolite, actinolite, anthophyllite), ceramic fibers(wine glass wool, quartz, aluminum oxide, silicon carbide) and fiber-metal(steel, light weight aluminum).
However, both of natural and man-made fiber reinforced concrete have their own obstacles and weakness. There is nothing being done without deficiencies. Synthetic fiber however has more obstacles than natural fiber content due to its production. Future development of natural and artificial fiber reinforced polymer concrete will make us want to investigate more about them.
To know about polymer concrete and why fiber being strengthened in it.
To illustrate the characteristics of natural and synthetic fiber reinforced polymer concrete.
To explain the troubles in environment when using both amalgamated materials in structure.
To describe the near future development in both composite materials.
Polymer concrete is a composite material where the binder consists entirely of a fabricated organic polymer. It is variously known as synthetic resin concrete, simply resin concrete or clear plastic resin concrete. Because the use of any polymer instead of Portland cement presents a substantial upsurge in cost, polymers should be utilized only in applications in which the more expensive can be justified by superior properties, low labor cost or low energy requirements during control and handling. It is therefore important that architects and technical engineers have some knowledge of the capacities and limitations of polymer concrete materials in order to select the most appropriate and economical product for a specific application.
Polymer concrete includes a nutrient filler such as an aggregate and a polymer binder which may be a thermoplastic, but more frequently, this can be a thermosetting polymer. When fine sand is used as a filler, the composite is known as a polymer mortar. Other fillers include chalk, gravel, limestone, smashed stone, condensed silica fume (silica flour, silica particles), quartz, clay, granite, expanded goblet, and metallic fillers. Generally, any dried up, non-absorbent, solid material can be utilized as a filler.
To produce polymer cement, a monomer or a pre-polymer which suggest a product caused by the incomplete polymerization of the monomer, a hardener (cross-linking agent) and a catalyst are mixed with the filler. Other materials put into the mixture include plasticizers and flames retardants. Sometimes, silane coupling agents are being used to raise the bond strength between your polymer matrix and the filler. To attain the full probable of polymer concrete products for certain applications, various dietary fiber reinforcements are being used. These include cup fiber, cup fiber-based mats, textiles and metal fibers. Preparing times and times for development of maximum power can be easily varied from a few momemts to several hours by modifying the heat and the catalyst system. The amount of polymer binder used is normally small and is usually dependant on the size of the filler. Normally the polymer content will range from 5 to 15 percent of the total weight, but if the filler is okay, up to 30 percent may be needed.
Polymer concrete composites have generally good amount of resistance to strike by chemicals and other corrosive real estate agents, good level of resistance to abrasion, have suprisingly low water sorption properties and good marked freeze-thaw balance. Also, the higher durability of polymer cement in comparison to that of Portland concrete concrete permits the utilization of up to 50 percent less material. This puts polymer concrete over a competitive basis with concrete concrete in certain special applications. The chemical substance level of resistance and physical properties are usually determined by the nature of the polymer binder to a greater level than by the type and the quantity of filler. Subsequently, the properties of the matrix polymer are highly reliant on time and the heat to which it is shown.
The viscoelastic properties of the polymer binder bring about high creep beliefs. This is one factor in the restricted use of polymer cement in structural applications. Its deformation response is highly variable depending on formulation ; the stretchy moduli may range between 20 to about 50 GPa, the tensile failure pressure being usually 1 percent. Shrinkage strains change with the polymer used. For example, high for polyester and low for epoxy-based binder. It must be studied into account within an application.
A wide selection of monomers and pre-polymers are being used to produce polymer concrete. The polymers most regularly used are based on four types of monomers or pre-polymer systems : methyl methacrylate (MMA), polyester pre-polymer-styrene, epoxide pre-polymer hardener (cross-linking monomer) and furfuryl alcohol.
Table 1 : Basic Characteristics And Applications of Polymer Cement Products
Low tendency to soak up water. As a result, high freeze-thaw resistance ; low rate of shrinkage during and after setting. Outdoor sturdiness and good chemical substance resistance.
Used in the manufacture of faade plates, stair devices and sanitary products for curbstones.
Good adhesion to other materials, relatively strong, good substance and freeze-thaw level of resistance but have high-setting and post-setting.
Because of less expensive, trusted in panels for public and commercial pipes, properties, floor tiles, stairs, various precast and cast-in applications in development works.
Strong adhesion to most building materials, low shrinkage, good creep and tiredness resistance, superior substance level of resistance and low normal water sorption.
Epoxy polymer products are relatively costly. They may be mainly utilized in special applications including utilization in mortar for industrial floor coverings, skid-resistant overlays in highways, epoxy plaster for external surfaces wall surfaces and resurfacing of deteriorated structures.
Composite materials with high level of resistance to chemicals which most acidic or basic aqueous marketing, strong level of resistance to polar organic and natural liquids such as ketones, aromatic hydrocarbons and chlorinated compounds.
Furan polymer mortars and grouts are being used for brick such as carbon brick and red shale brick, surfaces and linings that are resistant to chemicals, elevated temperatures and thermal shocks.
Source : Blaga, A. and Beaudoin, J. J. , (1985). Polymer Cement. Canadian Building Break down posted November 1985.
THE CHARACTERISTICS OF FIBER AND TOUGHNESS CONCEPT
Characteristics of dietary fiber in use to solidified concrete :
Fibers should be significantly stiffer than the matrix that includes a higher modulus of elasticity than the matrix.
Fiber content by quantity must be adequate.
There must be considered a good fiber-matrix connection.
Fiber period must be sufficient.
Fibers will need to have a higher aspect ratio. Implies that they need to be long relative to their diameter.
Toughness is thought as the area under a load-deflection (or stress-strain) curve. Adding fibres to cement greatly escalates the toughness of the material. That's, fiber-reinforced concrete can sustain insert at deflections or strains much greater than those at which breaking first appears in the matrix.
Potential use of natural fibers strengthened concrete in the use of natural fibres has long enticed the interest of experts. Various studies has been conducted in many countries for a variety of mechanical properties, physical performance and durability of materials reinforced by natural fibres. Natural fibers are categorized as organic waste materials from plants such as dietary fiber coconut, sisal, bagasse, jute, real wood dust etc.
Natural fiber strengthened concrete is actually a special cement where it contains fibers with a little diameter, separately and randomly allocated in the cement matrix. Uniform circulation in the cement matrix, contributing to an increase in the tensile and level of resistance to cracking, impact and upgraded the ductility prices for the good areas of energy absorption. Although many types of fibers were used as reinforce materials in concrete, the use of natural materials had always been around and there's a lot of evidence of the usage of these fibers in the annals of civilization. Aspect has given individual the fiber strengthened material by means of lumber, bamboo and other plants. The usage of straw in mud bricks and horses wild hair in the mortar has the potential of natural fibers.
Only in the later 1960s and early on 1970s, research started out to study the use of varied types of natural fibres as reinforcement material in the slab cement and cement-based amalgamated materials. Natural dietary fiber reinforced cement or concrete products that use materials such as coir, sisal, sugar bagasse, bamboo and so forth have been produced and examined in more than 40 countries. For economic reasons in producing countries where natural fibres is a whole lot available, it is demanding for building industry players to improve the usefulness of the resources in an effective and economical concerning introduce amalgamated materials for domestic use and more.
Basic needs use of natural fibers as reinforcement materials in concrete matrix is tensile power and high flexible modulus, the relationship between your matrix and fibre, good chemical structure, stable geometry and good durability.
Synthetic fibers are man-made fibres caused by research and development in the petrochemical and textile companies. You will discover two different physical fibre forms: monofilament materials, and fibers created from fibrillated tape. Currently there are two different artificial fiber volumes found in application, specifically low-volume ratio (0. 1 to 0. 3% by volume) and high-volume percentage (0. 4 to 0. 8% by level). Most fabricated fiber applications are at the 0. 1% by amount level. As of this level, the effectiveness of the concrete is known as unaffected and split control characteristics are desired. Fiber types which may have been tried in concrete matrices include : acrylic, aramid, carbon, nylon, polyester, polyethylene and polypropylene.
The characteristics is rely upon the types of synthetics used to reinforced with polymer concrete. Different fibers has different properties. Adding carbon fibre decreased the machine weight of polymer concrete. Carbon dietary fiber provides higher compressive durability, flexure durability and ductility of polymer cement. PVC and polypropylene fibers did not significantly affect the compressive durability and gave the lowest pulse velocities and modulus.
The issues of polymer cement are the monomers of polymer can be volatile, combustible and harmful. Initiators, which are used as catalysts, are combustible and harmful to human epidermis. The promoters and accelerators are also dangerous.
Natural fibres are growing as lightweight, low priced, and more environmentally somewhat than synthetic fibers in composites. This is because :
A compound strengthened with natural fibers is not only low denseness, low-cost, and abrasion resistant, it also offers an lack of toxicity and better dimensional stableness.
Polyester raw material releases high levels of skin tightening and. This rapidly heightens global warming, which explains why polyester and other artificial fabrics are broadly discouraged. The other reason is that some synthetic textiles come from non-renewable resources such as engine oil. Eventually rise of the synthetic fibers usage have been creating environmental problems such as dumping and recycling. In addition, glass fiber content can cause severe irritation of the skin, eyes, and respiratory system. Mainly concerns have been increased for permanent disease such as cancer and lung scarring. Furthermore, when released, a glass fiber does not decompose and therefore again it brings about environmental pollutions, as well as, threaten pet animal life and dynamics along.
Therefore, one of the solutions is using natural fibres instead of man-made fibers in growing composites materials because they are renewable. Also the consumption of alternative resources would provide positive image for sustainability of inexperienced environment. Natural fibres are less bad for the surroundings and the society because they're derived from plant life and pets or animals which are more eco-friendly. Products which made from natural fabric eventually dissolves into the earth. Plant and animal centered fabrics are a part of the evolutionary procedure for life. They return to the earth to return once more to life.
Synthetic fibers are more threatening to the environment because they're improved with chemicals. Polyester and nylon textiles are produced from a product which creates nitrous oxide. Materials that are labeled petrochemical, fire retardants, nylon, acetate and non-wrinkle are all chemically cured. Chemicals which used for the production of synthetic fabric is hazardous and can enter the water supply and cause health problems. Also staff who are consistently subjected to dangerous chemicals are at risk for growing auto-immune diseases and disease of the lung. Products created from petrochemicals take years to break down, creating a constant dependence on landfills. Synthetic products that are disposed into the ocean are a threat to marine life. The threat to aquatic family pets will eventually precipitate a food scarcity.
Although, synthetic fibres may offer softer fabric and more durable materials, the long term effect on the surroundings very good outweigh any advantages. The high cost of petrol along with global awareness of how natural fibres improve overall quality of life will help encourage manufacturers to find more innovative ways to make use of natural fibres.
Synthetic : However is not investigated extensively, the utilization of two or more fiber types in the same concrete mix is considered promising. The decision to mix two materials may be predicated on the properties that they may individually provide or simply predicated on economics. Substantial improvement in the strain deflection response was noticed mixing material with polypropylene fibers. In a more recent study, steel micro-fibers (25 microns in diameter and 3 mm long) and carbon micro-fibers (18 microns in diameter and 6 mm long) both in mono- and hybrid- forms were investigated. In the mono-form, steel fibers provided better strengthening than the carbon fibre and carbon fibers provided better toughening than the steel fiber. Oddly enough, in the cross types form (in combination), they both maintained their specific capacities to fortify and toughen. It seems possible, therefore, that by properly managing fiber content properties and incorporating them in appropriate proportions, one can actually tailor-make cross fibre composites for created specifically applications.
Natural : Environmental awareness and depletion of the petroleum resources are among vital factors that stimulate a number of analysts to explore the potential of reusing natural fiber content alternatively composite materials in business such as presentation, motor vehicle and building constructions. However, their applications remain limited due to several factors like moisture absorption, poor wettability and large scattering in mechanised properties. Among the primary troubles on natural materials strengthened matrices composite is their inclination to entangle and form materials agglomerates during processing anticipated to fiber-fiber conversation. So, the study on natural fibers is being done by mercerization treatment on mechanical properties augmentation of natural fibre reinforced amalgamated or so-called bio composite. It specifically talked about on mercerization parameters, and natural fiber content reinforced composite mechanical properties enhancement. It was discovered that the most parameters found in mercerization treatment were alkali focus, fiber soaking heat range and fibre soaking duration. Although similar types of strengthened fiber are used, it could give different values in its last composite mechanical properties due to different parameter setting up throughout a mercerization treatment process. Therefore, there is a significant need to perform further work concentrating on main impact and interaction effect of mercerization parameters placing toward improvement of natural fiber content reinforce composite mechanised properties.
In final result, natural fiber strengthened polymer concrete has more environmentally characteristics than the man-made one. But, in the context of advantages, synthetic fiber reinforced polymer cement has more than natural. Both of them have their own advantages and disadvantages. Because of several characteristics of natural materials such as moisture absorption, poor wettability and large scattering in mechanised properties, thus it makes reinforcement with polymer concrete a lttle bit less helpful. Future works will be had a need to improve the properties of both natural and fabricated fiber reinforced polymer concrete included with environment impacts.
All praises to Allah, with His power and love, finally I have finished this statement. A whole lot of thanks a lot especially to my advisor and my lecturer of Honours Seminar, Dr Azwani Sofia binti Ahmad Khiar and Dr Khairi bin Abdul Rahim because of their encouragement, aids and guidance in making this report. Finally, an appreciation also to my friends.