Experimental Investigation on Polypropylene Fiber Reinforced Concrete With Artificial
The paper presents research work of experimental investigation on polypropylene fiber reinforced concrete by replacing river sand to artificial sand with and without admixture. Use of fiber reinforce polymer in civil engineering increase rapidly. Various type of fiber is used such as glass, carbon, steel, asbestos, polyester and polypropylene. The various experimental investigations for determination of properties of polypropylene fiber are discussed in paper work. This paper presents the effect of polypropylene (PP) fibers on various properties of concrete such as compressive strength, tensile strength, workability, and fracture properties with various content of fiber(0% ,0.5%,1.0%,1.5%). The result of this present investigation indicates that by adding of 0.5% of polypropylene fiber shows maximum compressive and tensile strength.
INFLUENCE OF VARIATION OF LENGTH AND DOSAGE OF NYLON FIBER ON COMPRESSIVE AND SPLIT TENSILE STRENGTH OF CONCRETE
1Student, M. Tech(Structural Engineering) G.E.C. Jagdalpur 2Principal, G.E.C. Jagdalpur 3Assistant Professor, Dept. of Civil Engineering, G.E.C. Jagdalpur, Chhattisgarh, India ---------------------------------------------------------------------***---------------------------------------------------------------------Abstract – Nylon cable tie-fibre reinforced concrete is investigated for its compressive and split tensile strength after 7days and 28 days of curing in water, as nylon fibre which is able to withstand a certain amount of stress before it breaks, which is then compared to that of conventional concrete. Standard concrete cube and cylinder of Grade 20 was casted as trial samples to test the mix designed. Nylon cable ties were cut to length of 30mm and 50 mm with aspects ratios of 120 and 200 respectively. The concentration of nylon cable tie content is varied in percentages of 0.0%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, and 0.6% of weight of concrete used i.e. small dosage (below 5 kg/m3), medium dosage (5-10 kg/m3) and small dosage (above 10 kg/m3). The optimum nylon cable tie content for both compressive and split tensile strength was obtained, which is at 0.3%(medium dosage) fibre content and 30mm length. NFRC shows a higher compressive strength and higher tensile strength compared to the controlled concrete because when FRC cracks due to load being applied to it; the fibres were activated, arresting the formation of further cracks. When using higher dosage the strength decreases as the concrete workability decreases which will trap more air than highly workable concrete, creating larger voids and honeycombed surface and the existence of this large air voids reduces the strength of concrete due to less friction and poor interlocking between aggregates. The crack bridging effect of fibres that are existent at the crack face allows additional stress to be taken by the Post-Failure Compressive Strength.
Applications of nanocomposite hydrogels for biomedical engineering and environmental protection
Nanocomposite hydrogels are polymeric networks that possess a unique property of hydration. The presence of alcohols, carboxylic acids and amides as hydrophilic moieties in structure of nanocomposite hydrogels enhances their stiffness and water-absorbing capacity. Addition of cross-linker in the synthesis of hydrogels increases their stability under extreme conditions of temperature, pH and pressure. Natural polymer-based nanocomposite hydrogels are biodegradable, highly hydrophilic and possess good mechanical strength. Gelatin, chitin, cellulose, pectin, carrageenan, starch and alginate are natural polymers commonly used to fabricate nanocomposite hydrogels. Nanocomposite hydrogels have special characteristics such as high swelling rate, selectivity and stimuli-sensitive nature. Here we review nanocomposite hydrogels for environmental protection and biomedical engineering. Applications in biomedical engineering include drug delivery agents, wound dressing, tissue engineering and antibacterials. Applications in environmental protection include ion exchangers, adsorption, photocatalysis and soil conditioning. Many nanocomposite hydrogels show excellent adsorption selectivity for heavy metal ions: Cu2+ up to 30.35 mg/g, Pb2+ up to 35.94 mg/g, and Zn2+ and Fe3+ up to 94.34 mg/g. Xanthan gum-based nanocomposite hydrogel has removed 96% dye from industrial effluent as reported. In addition, most of the nanocomposite hydrogels showed better adsorption capacity for pollutants in the pH range from 5 to 7. The nanocomposite hydrogels could also be regenerated and successfully utilized for several times. Nanocomposite hydrogels are therefore good bio-absorbent materials for environmental detoxification.