بررسی آزمایشگاهی و آماری مقاومت فشاری و کششی بتن پودری (RPC) در سنین مختلف

نوع مقاله : علمی - پژوهشی

نویسندگان

1 گروه عمران، واحد یزد، دانشگاه آزاد اسلامی، یزد، ایران.

2 گروه عمران، دانشکده مهندسی، دانشگاه فردوسی مشهد، مشهد، ایران

3 گروه عمران، دانشکده مهندسی، دانشگاه فردوسی مشهد، مشهد، ایران.

چکیده

در حال حاضر، انواع خاصی از بتن نظیر بتن فوق‌توانمند (UHPC) ، دست‌یابی به برخی از ویژگی‌های بتن از جمله مقاومت بالا را میسر می‌سازد. بتن پودری (RPC) از جمله بتن‌های فوق‌توانمند با ویژگی‌های فیزیکی و مکانیکی برتر است. بتن پودری با بهره‌گیری از سیمان و مصالح پودری بسیار ریزدانه شامل ماسه سیلیسی، میکرو سیلیس و مقادیر کم نسبت آب به سیمان با استفاده از فوق‌روان‌کننده تولید می‌گردد. در این پژوهش، ابتدا طرح اختلاط RPC که در آن نسبت آب به مواد پودری (W/B) برابر 15/0 و نسبت فوق‌روان‌کننده به سیمان (SP/C) برابر با 3 درصد می‌باشد، با بهره‌جویی از مصالح بومی و با استفاده از مطالعات قبلی انتخاب و تعیین گردید. در ادامه، با انجام آزمایش‌های متعدد، مقاومت فشاری، مدول گسیختگی و مقاومت کششی در سنین مختلف اندازه‌گیری گردید. به منظور تعیین مقاومت RPC در سنین مختلف، نمونه‌هایی با W/B و SP/C برابر با طرح اختلاط ساخته شد و پس از عمل‌آوری معمولی در سنین 3، 7، 14، 28 و 56 روزه مورد آزمایش قرار گرفت. هر گروه شامل شش نمونه بود و مقدار میانگین، انحراف معیار و ضریب پراکندگی نمونه‌ها تعیین شد. در این مقاله، با استفاده از نتایج آزمایش‌های انجام شده، رابطه‌هایی برای تعیین مقاومت فشاری و کششی بتن‌ پودری در سنین مختلف پیشنهاد شده است که از دقت مناسبی برخوردار بوده و می‌تواند در عمل مورد استفاده قرار گیرد.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Experimental Investigation and Statistical Analysis of Compressive and Tensile Strength of Reactive Powder Concrete (RPC) at Different Ages

نویسندگان [English]

  • Mohammad Ali Dashti Ramatabadi 1
  • Farzad Shahabian 2
  • Hasan Haji Kazemi 3
1 Department of Civil Engineering,Yazd Branch, Islamic Azad University, Yazd, Iran.
2 Department of Civil Engineering, Ferdowsi University of Mashhad, Mashhad, Iran
3 Department of Civil Engineering, Faculty of Engineering, Ferdowsi University of Mashhad, Mashhad, Iran.
چکیده [English]

At present, certain types of concrete such as ultra high performance concrete (UHPC) provide some concrete properties such as high resistance. Reactive powder concrete (RPC) is one of the UHPC concrete with superior physical and mechanical properties. Reactive powder concrete is produced using cement and very fine powdered materials including crushed quartz, silica fume and low water-to-cement ratio using super plasticizer. In this study, a mixing scheme of RPC, in which water/binder ratio (W/B) is equal to 0.15 and the ratio of super plasticizer to cement (SP/C), is equal to 3%, with interest of the selection of native materials was determined. Subsequently, by performing several experiments, the compressive strength, rupture modulus and tensile strength of RPC have been investigated at different ages. In order to determine the resistance of RPC at different ages, samples with W/B and SP/C were made up to the mixing scheme and tested after 3, 7, 14, 28 and 56 days of normal operation. Each group consisted of six samples, and the mean values, standard deviation and coefficients of variations of the samples were determined. The relationships have been proposed to predict the compressive and tensile strength of reactive powder concrete in different ages, which are accurate and can be used in practice.

کلیدواژه‌ها [English]

  • Reactive powder Concrete
  • ultra high performance concrete
  • Compressive strength
  • tensile strength
  • Super Plasticizer
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