ارزيابي اثر همزمان لاستيك و الياف فولادي بازيافت شده از تاير ضايعاتي بر مقاومت سايشي بتن

امروزه از معضلات اصلي بشر حفظ محيط زيست در برابر وجود مواد ضايعاتي است. استفاده مجدد اين مواد همچون لاستيك تاير ضايعاتي به عنوان جايگزيني بخشي از مصالح در ساخت بتن به عنوان يك استراتژي اساسي جهت دستيابي به توسعه پايدار محسوب مي‌شود. در اين پژوهش به‌كارگيري همزمان پودر و خرده لاستيك و سيم و الياف فولادي بازيافت شده از تاير ضايعاتي در مخلوط بتن، مورد بررسي مقاومت‌هاي سايشي و فشاري و وزن واحد حجم بتن قرار گرفته است. در پژوهش حاضر در 12 طرح اختلاط از جايگزيني پودر و خرده لاستيك با ماسه به مقدار 9، 13/5، 18، 22/5 و 27 درصد حجمي ماسه و افزودن سيم و الياف فولادي بازيافتي از تاير به مقدار 0/5 درصد حجمي استفاده شده است. نتايج آزمايشات نشان مي‌دهد افزودن 0/5 درصد الياف فولادي بازيافتي به بتن حاوي 9 درصد پودر و خرده لاستيك، كاهش مقاومت فشاري را بهبود مي‌بخشد و باعث افزايش مقاومت سايشي مي‌شود. با افزايش درصد‌هاي جايگزيني پودر و خرده لاستيك با ماسه در مخلوط بتن همراه با 0/5 درصد الياف فولادي بازيافتي، مقاومت سايشي بتن افزايش اما مقاومت فشاري و وزن واحد حجم بتن كاهش مي‌يابد. مقاومت سايشي اين نوع بتن‌هاي حاوي مواد ضايعاتي نسبت به بتن شاهد تا 37/5 درصد افزايش داشته است.

Nowadays, one of the main problems of human being is the protection of the environment against the presence of waste materials. Every year millions of tires are discarded, thrown away or buried all over the world. One of these waste materials, waste tires are. Wired tires are made of rubber particles and steel fibers. Past research has shown that rubber particles and recycled steel fiber from waste tire, can be used in concrete. This type of steel fibers can have a positive effect on the mechanical properties of concrete. Rubber particles in concrete reduce the compressive strength. In some studies, it has been shown that rubber particles increase or decrease the abrasion resistance of concrete, and even the size of the rubber particles also affect the abrasion resistance of concrete. In this research, simultaneous application of powder and crumb rubber, wire and recycled steel fibers from waste tire in concrete mixture, has been investigated to study the abrasion and compressive strengths and unit weight of concrete. In this research, in 12 mixing designs, replacing of powder and crumb rubber with sand to the amount 9%, 13.5%, 18%, 22.5% and 27% by volume of sand and adding 0.5% by volume of wire and recycled steel fibers from waste tire has been used. In all designs, the cement cutie is 380 and the ratio of water to cement is 0.47 constant. In this research, different samples are compared with the control sample. Compressive strength were performed after 7 and 28 days. Also, abrasive resistance and weight per unit volume were performed after 28 days. The results of the experiments show that rubber particles with a fine gradation will have a better impact on the abrasion resistance. But this is not so that about compressive strength and it reduces more resistance. Based on the results, adding 0.5% recycled steel fibers with a length ratio to high diameter to concrete containing 9% of powder and crumb rubber, reduction in compressive strength improves and cause increased abrasion resistance. But the adding steel wire to concrete containing powder and crumb rubber reduces the abrasion resistance. Use the powder and crumb rubber with 0.5% recycled steel fibers, reduces the compressive strength and by increasing the amount of powder and crumb rubber, reduction of resistance will be more. The abrasion resistance of concrete containing powder and crumb rubber with with 0.5% recycled steel fibers is increased relative to the control concrete. By increasing the powder and crumb rubber content, the abrasion resistance increases, but this upward trend occurs to a certain percentage of powder and crumb rubber replacement with sand, and then the percentage of increasing abrasion resistance decreases. By increasing the powder and crumb rubber, weight loss will be increased. From this perspective, it causes the lightness of concrete which can be the advantage of using these waste materials in concrete. The abrasion resistance of concrete containing 9% of powder and crumb rubber with 0.5% recycled steel fibers has increased up to 37.5% relative to the control concrete.