تاثیر میکروسیلیس و زئولیت بر رفتار میان مدت بتن خودمتراکم منبسط شونده

نوع مقاله : علمی - پژوهشی

نویسندگان

1 دانشگاه صنعتی نوشیروانی بابل

2 استاد، دانشگاه علم و صنعت، تهران، ایران

3 گروه عمران،موسسه آموزش عالی صالحان،قائمشهر،ایران

4 موسسه آموزش عالی علوم و فناوری آریان

چکیده

بتن خودتراکم یک نوآوری در زمینه بتن می‌باشد که باعث رفع یکی از مشکلات اساسی در ساخت سازه‌های بتنی یعنی مشکل تراکم بتن، گردیده است. این نوع بتن با ترکیب جدید و ابداع ابر روان‌کننده موجب شده است که ترکیب یکنواخت در بتن ایجاد شود. در تحقیق حاضر تاثیر افزودنی‌های زئولیت و میکروسیلیس و جایگزینی آن‌ها با بخشی از سیمان به کمک آزمایشات خواص مکانیکی شامل مقاومت فشاری، کششی، خمشی و امواج فراصوت بر روی نمونۀ شاهد بتن خودمتراکم و بتن خودمتراکم منبسط شونده مورد ارزیابی قرار گرفته است. همچنین تغییر شکل کوتاه مدت حاصل از جمع‌شدگی بتن خودتراکم در اثر خشک شدن برای دورۀ 210 روزه پس از ساخت نمونه‌ها مورد بررسی قرار گرفته است. نتایج آزمایشگاهی به دست آمده نشان داده است که پوزولان‌های میکروسیلیس و زئولیت سبب بهبود در ریزساختار بتن‌های مورد مطالعه شده که این امر باعث بهبود در خواص مکانیکی می‌گردد. در حقیقت جایگزینی سیمان با پوزولان‌ها سبب شده که قسمت‌های ناحیه انتقال نمونه‌ها بهتر و متراکم‌تر شوند. همچنین نتایج آزمایش جمع-شدگی نشان می‌دهد که پوزولان‌های زئولیت و میکروسیلیس منجر به کاهش قابل توجهی در جمع شدگی خشک می‌‌شوند. جمع-شدگی خشک بتن حاوی 15 درصد زئولیت و 5/7 درصد میکروسیلیس نسبت به بتن شاهد حاوی مواد منبسط شونده در سن 210 روز به ترتیب به میزان 32 و 15 درصد کاهش یافته‌اند.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Influence of Silica Fume and Zeolite on the Mid-Term Behavior of Expansive Self-Compacting Concrete

نویسندگان [English]

  • Abdul Sattar Safaei 1
  • Gholamreza Ghodrati Amiri 2
  • seyed mohammad hossein razavi 3
  • Hamidreza Hosseinali Beygi 4
1 Babol Noshirvani University of Thechnology
2 Professor, Department of Civil Engineering, Iran University of Science & Technology, Tehran, Iran
3 Salehan Institute of Higher Education, Ghaemshahr, Iran
4 Aryan Institute of Science and Technology
چکیده [English]

Self-compacting concrete is an innovation in the field of concrete that has resolved one of the main problems in the construction of concrete structures, namely the problem of concrete compaction. This type of concrete has caused a uniform composition in concrete with a new composition and the invention of superplasticizer. In the present study, the effect of introducing the additives of zeolite and micro silica and their replacement with a part of cement has been evaluated by testing the mechanical properties including compressive, tensile, flexural and ultrasonic waves tests on the control specimen of self-compacting concrete and expansive self-compacting concrete. Also, the short-term deformation due to shrinkage of self-compacting concrete caused by drying for a period of 210 days after the fabrication of specimens has been investigated. Experimental results have shown that micro silica and zeolite pozzolans improve the microstructure of the evaluated concrete, which improves the mechanical properties. In fact, the replacement of cement with pozzolans has made the parts of the transition zone of the specimens better and condensed. Shrinkage test results also show that zeolite and micro silica pozzolans lead to a significant reduction in drying shrinkage. Drying shrinkage of the concrete containing 15% zeolite and 7.5% micro silica decreased by 32% and 15% compared to the control concrete containing expansive materials at the age of 210 days, respectively.

کلیدواژه‌ها [English]

  • Self-Compacting Concrete
  • Compressive strength
  • Tensile
  • Flexural
  • Shrinkage
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