بررسی آزمایشگاهی تاثیر الیاف فولادی بر مقاومت مکانیکی و ضربه‌ای دال های کامپوزیتی خود تراکم

نوع مقاله : علمی - پژوهشی

نویسندگان

1 استادیار، گروه مهندسی عمران، دانشگاه لرستان

2 استاد یار دانشکده مهندسی دانشگاه لرستان، خرم اباد، ایران

3 دانشجوی کارشناسی ارشد دانشگاه لرستان

چکیده

استفاده از کامپوزیت های توانمند خود تراکم به دلیل ویژگی های منحصر به فرد آن، مورد توجه محققین قرار گرفته است. مقاومت فشاری و کششی بالا، مقاومت خمشی بالا موجب توجه بیش از پیش محققین، به این نوع از کامپوزیت های سیمانی شده است. در این تحقیق در قالب یک کار جامع آزمایشگاهی با استفاده از 6 طرح اختلاط پایه، 24 دال کامپوزیتی مستطیلی به ابعاد 300 در 400 میلیمتر با دو ضخامت 30 و 50 میلیمترساخته و تحت بار ضربه ای تست گردید. بر روی هر شش طرح اختلاط ساخته شده آزمایش های مقاومت فشاری، کششی و خمشی انجام گردید. همچنین به منظور تعیین کارایی کامپوزیت های توانمند، آزمایش‌های اسلامپ روانی، قیف Vشکل، جعبه L شکل و قیف U شکل بر روی طرح اختلاط ها انجام گردید. از الیاف فولادی با درصد های 0، 5/0 و 1 درصد حجمی و با طول های 25 و 50 میلی‌متر به منظور ساخت کامپوزیت های سیمانی استفاده شد. دستگاه آزمایش ضربه از یک گوی فولادی به وزن 6/5 کیلوگرم و یک سیستم نگه دارنده ساخته شد. گوی فولادی تا ارتفاع 5/1 متر بالا برده شده و بصورت مکرر تا ایجاد گسیختگی در نمونه ها، رها گردید. مطابق با نتایج حاصل از آزمایش، ملاحظه گردید که حداکثرجذب انرژی در دال با ضخامت 30 میلی‌متر 22/34 کیلوژول و در دال با ضخامت 50 میلی‌متر79/47 کیلوژول می‌باشد. نتایج حاصل از این آزمایش نشان دهنده تاثیر بالای الیاف فولادی در افزایش مقاومت ضربه ای و انرژی جذب شده دال‌ها می‌باشد.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Experimental investigation of the effect of steel fibers on mechanical and impact strength of self-compacting composite slabs

نویسندگان [English]

  • Ahmad Dalvand 1
  • amir mohammad amiri 2
  • behnaz jahangiri 3
1 Assistant professor, faculty of engineering, lorestan university,khorramabad, iran
2 assistant professor, faculty of engineering, lorestan university,khorramabad, iran
3 Master student of Lorestan University,khorramabad, iran
چکیده [English]

The use of self-compacting high performance composites due to its unique properties has attracted the attention of researchers.The high compressive strength and tensile strength, high flexural strength, have attracted the attention of researchers to this type of cement composites.In this research, in the form of a comprehensive experimental work, using six basic mixing designs, 24 rectangular composite slabs 300 to 400 mm, with two thicknesses of 30 and 50 mm, were built and tested under impact load. Compressive,tensile and flexural strength tests were made on each of the six mixing designs. Also, to determine the efficacy of high performance composite, slump flow, L-box, U-box and V-funnel on mix designs have been done. Steel fibers with percentages of 0, 0.5 and 1% by volume fraction, with lengths of 25 and 50 mm, were used for the construction of cementitious composites. The impact test apparatus was made from a 5.6 kilogram steel ball and a retaining system. The steel ball was raised to a height of 1.5 meters and was freed repeatedly until failure cracking in the samples have been Developed. According to the results of the experiment, It was noted that the maximum energy absorption in a slab with a thickness of 30 mm was 34.22 kJ, and in a slab with a thickness of 50 mm was 47.49 kJ. The results of this experiment shows the high effect of steel fibers on increasing the impact resistance and absorbed energy of the composite slabs.

کلیدواژه‌ها [English]

  • cementitious composite
  • impact strength
  • Flexural Strength
  • Steel Fibers
  • tensile strength
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