بررسی اثر الیاف بازیافتی از جنس پلی اتیلن ترافتالات (PET) بر خواص مکانیکی بتن

Disposal of Waste materials is a major challenge in each country and the use of plastics materials is increasing every day. A large part of the plastic wastes are bottles of drinks which are made of Polyethylene terephthalate (PET). The reuse of plastic wastes plays an important role in sustainable solid waste management. Plastic waste management helps to save natural resources that cannot be replenished, decreases pollution of the environment and also helps to save and recycle energy production processes. Now a days , PET has been widely used to produce fibers, particles, or lakes to obtain cement-based products with improved properties One transcendental alternative to recycling PET materials consists of using them as substitute of concrete aggregates. Due to demands of technological development in the construction area, the possibility for generating alternative materials that can be applied with increasing functionality, low costs, and better physical, chemical, and mechanical properties than conventional materials is being explored Fiber-reinforced concrete is a composite material resulting from the addition of reinforcing fibers to the brittle matrix of ordinary concrete. The idea of using fiber reinforcement comes from the need to find a remedy to the phenomena of cracking, such as produced by shrinkage, which inevitably affects the service life of concrete buildings. Concrete is a material that is well resistant to compression, but has low tensile strength. The low level of tensile strength is caused by phenomena such as plastic and/or hydraulic shrinkage with the formation of unwanted micro and macro cracks Fiber-reinforced concrete represents the current tendency to apply more eficient crack-resistant concrete. The ability to enhance flexural and tensile performance of the concrete matrix, together with the opportunity for improving its durability, pushed boundaries in developing new materials to be used as fibres. Several studies using reinforced concrete with polymer fibers like polypropylene, polystyrene, polyethylene terephthalate, and polyethylene have evidenced variation of concrete properties according to the nature and size of the aggregate . The level of fibre performance depends strongly on the quality and amount of the employed fibres applied, on their shape and dimensions as well as on their bond to the concrete matrix . One way for recycling and efficient use of PET is adding to the concrete as fibers. Use of PET fibers in concrete will solve environmental problem of this waste material in addition to improvement of mechanical properties of concrete. Research on the use of PET fibres as dispersed reinforcement in concrete and mortars has been ongoing for about a decade with sporadic studies. In this research physical and mechanical behavior of concrete containing recycled PET fiber has been studies. For this purpose 10 concrete mixture, including 1control mixture and 9 pet fiber concrete mixtures were made. Fibers in volume percentage of 0.15%, 0.30% and 0.45% with the length of 1, 2 and 3 cm were used separately. Compressive strength, tensile strength and flexural strength tests were done on the samples. Fibers deformed with deforming machine to improve the adhesion of fiber with concrete. Compressive strength were performed ater 7 and 28 days. The results show that PET fibers increase. Compressive strength and flexural strength of concrete between 5-18% and 6%- 30% respectively. No significant efects on tensile strength were observed with the addition of fibers.