ارزیابی خواص مکانیکی بتن بازیافتی مسلح به الیاف؛ تأثیر ابعاد و میزان سنگدانه بازیافتی، نوع و میزان الیاف

نوع مقاله: علمی - پژوهشی

نویسندگان

1 دانشجوی کارشناسی ارشد مهندسی سازه، دانشگاه کاشان، کاشان، ایران

2 استادیار، دانشگاه کاشان، کاشان، ایران

چکیده

در این تحقیق از سنگدانه‌های بتنی بازیافتی به جای سنگدانه‌های طبیعی در بتن استفاده می‌شود و سپس بتن بازیافتی به وسیله الیاف تقویت می‌گردد. هدف از این مطالعه در ابتدا بررسی تأثیر ابعاد و همچنین میزان جایگزینی سنگدانه‌های بتنی بازیافتی بر خواص مکانیکی بتن و سپس بررسی تأثیر الیاف پلی‌پروپیلن و فولادی در بهبود خواص مکانیکی بتن بازیافتی است. نتایج نشان می‌دهد که با افزایش درصد جایگزینی مصالح بازیافتی به جای مصالح طبیعی، مقاومت فشاری بتن کاسته می‌شود. همچنین جایگزینی ماسه بازیافتی تا میزان 30 درصد، کاهش چندانی بر مقاومت فشاری بتن ندارد و می‌تواند به عنوان طرح اختلاط بهینه بتن بازیافتی مدنظر قرار گیرد. علاوه بر این در صورت استفاده از الیاف، مقاومت کششی و خمشی بتن بازیافتی به طور قابل توجهی افزایش می‌یابد که در این میان، الیاف فولادی نسبت به الیاف پلی‌پروپیلن از کارایی بالاتری در بهبود مقاومت کششی و خمشی بتن برخوردار است. همچنین بتن تقویت شده با الیاف پس از شکسته شدن، خرد و از هم گسیخته نمی‌شود و الیاف در حفظ پیوستگی بتن و جلوگیری از گسترش ترک‌ها نقش مهمی ایفا می‌کند.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Evaluation of mechanical properties of fiber reinforced recycled concrete: effect of size and amount of recycled aggregate, type and amount of fibers

نویسندگان [English]

  • Mehran Shirani Bid Abadi 1
  • Mahmood Akbari 2
1 MSc student, Department of Civil Engineering, Engineering Faculty, University of Kashan, Kashan, Iran
2 Assistant Professor, Department of Civil Engineering, Faculty of Engineering, University of Kashan, Kashan, Iran
چکیده [English]

In this research, recycled concrete aggregates are used instead of natural aggregates in concrete and then the recycled concrete is reinforced by fibers. The aim of this study is to investigate the effect of size and also the amount of the recycled concrete aggregates on the mechanical properties of concrete and then investigating the effect of addition of polypropylene and steel fibers on improving the mechanical properties of concrete. The results showed that compressive strength of concrete decreased by increasing replacement ratio of recycled aggregates. Also, the replacement of fine aggregate at the level of 30 percent has not significant effect on the compressive strength of concrete and so this mix can be selected as the optimum recycled mix design. In addition, the use of the fiber improves considerably the tensile and flexural strength of the recycled concrete so that the steel fiber has more positive effects on the tensile and flexural strength in comparison to the polypropylene fiber. In addition, when the concrete reinforced by the fiber is broken, the concrete is not disrupted and the fiber has an important role to reduce the growth of cracks after break.
In this research, recycled concrete aggregates are used instead of natural aggregates in concrete and then the recycled concrete is reinforced by fibers. The aim of this study is to investigate the effect of size and also the amount of the recycled concrete aggregates on the mechanical properties of concrete and then investigating the effect of addition of polypropylene and steel fibers on improving the mechanical properties of concrete. The results showed that compressive strength of concrete decreased by increasing replacement ratio of recycled aggregates.Also, the replacement of fine aggregate at the level of 30 percent has not significant effect on the compressive strength of concrete and so this mix design can be selected as the optimum recycled mix design. In addition, the use of the fibers improve considerably the tensile and flexural strength of the recycled concrete so that the steel fiber has more positive effects on the tensile and flexural strength in comparison to the polypropylene fiber. Also, when the concrete reinforced by the fiber is broken, the concrete is not disrupted and the fiber has an important role to reduce the growth of cracks after break.

کلیدواژه‌ها [English]

  • Recycled Concrete
  • Recycled aggregate
  • Mechanical properties
  • Steel Fiber
  • Polypropylene fiber

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