مطالعه‌ای بر مقاومت فشاری، مدول الاستیسیته استاتیکی و دینامیکی بتن‌های خودتراکم حاوی نانو مواد

نوع مقاله : علمی - پژوهشی

نویسندگان

1 گروه عمران- دانشکده فنی-دانشگاه گیلان-رشت

2 کارشناسی ارشد عمران گرایش سازه، دانشگاه گیلان، ایران

چکیده

در این مطالعه تأثیر انواع نانو مواد نظیر نانو اکسید‌های سیلیس (NS)، آلومینیوم (NA) و مس (NC) بر مقاومت فشاری (f’c)، مدول الاستیسیته استاتیکی(Ee)، رابطه f’c - Ee و رابطه مدول الاستیسیته استاتیکی و دینامیکی (Ed) در بتن‌های خودتراکم بررسی گردید. نانو مواد مذکور به عنوان ماده چسباننده جایگزین بخشی از وزن سیمان استفاده شدند. برای این منظور نمونه‌های استوانه‌ای استاندارد حاوی NS، NA و NC به ترتیب با مقادیر 5/1، 25/0 و 25/0 درصد، در سنین بین ۳ تا ۹۰ روز تحت آزمایش‌های f’c مطابق ASTM C39/39M-16b، Ee مطابق ASTM C469/c469M-14 و Ed مطابق ASTM C597-16 قرار گرفتند. نتایچ نشان داد که افزودن نانو مواد باعث بهبود مقاومت فشاری و مدول الاستیسیته گردید. روابطی جدید بین مقاومت فشاری و Ee و همچنین روابطی خطی میان Ee و Ed برای این نوع بتن‌های خودتراکم تعریف شد و مشاهده شد که نوع و مقدار نانو مواد، فارق از نوع آن، بر این روابط اثر گذار است. در سنین اولیه Ee اندازه گیری شده کمتر از Ee محاسبه شده از آیین‌نامه‌های ACI 318-14، ACI 363-10 و CSA A23.3-14 است اما با افزایش مقاومت اختلاف میان این دو کاهش یافت و به نظر میرسد که در مقاومت‌های بالاتر از ۴۵ مگاپاسکال Ee تخمین زده شده در این مطالعه بیشتر از Ee محاسبه شده از رابطه ACI 363-10 است. همواره Ed از Ee بیشتر است و با افزایش مقاومت اختلاف آن‌ها کاهش می‌یابد. همچنین مشاهده گردید که اختلاف میان Ee و Ed در بتن‌های خودتراکم این مطالعه بیشتر از اختلاف آن‌ها در روابط پیشنهادی آیین‌نامه 2 BS 8110: Part و مطالعات گذشته است.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

A study on compressive strength, static and dynamic elastic modulus of self-compacted concrete contained nanomaterials

نویسندگان [English]

  • Rahmat Madandoust 1
  • Saber Deilami Poshtjouei 2
1 Department of Civil Engineering, Faculty of Engineering, University of Guilan
2 Master of Science, Department of Civil Engineering, University of Guilan, Rasht, Iran
چکیده [English]

In this study, the influence of different kinds of nanomaterials such as Nano oxides of Silica (NS), Aluminum (NA) and Copper (NC) on compressive strength (f’c), static elastic modulus (Ee), relationship between f’c and Ee and the relationship between static and dynamic elastic modulus (Ed) of self-compacted concrete are examined. The nanomaterials are used as the binder in replacement of Portland cement. For this purpose, standard cylindrical samples containing NS, NA and NC with amounts of 1.5, 0.25 and 0.25%, respectively, were tested between 3 and 90 days. The f’c, Ee and Ed are evaluated according to ASTM C39/39M-16b, ASTM C469/C469M-14 and ASTM C597-16, respectively. Results indicate that adding Nanomaterials lead to improvement of f’c and elasticity module. New relations between f’c and Ee and, also, linear relation between Ee and Ed defined for this kind of self-compacted concretes, and it was observed that type and quantity of the Nanomaterials have impact on these relations. The experimental data of Ee at early ages are smaller than the calculated values of Ee from recommended equations by ACI 318-14, ACI 363-10, and CSA A23.3-14. The difference between experimental data and calculated values of Ee is decreased when f’c increases. when the f’c is higher than 45 MPa, the experimental data of Ee are higher than the calculated values of ACI 363-10. The study indicate that the Ed is always greater than the Ee and the difference between Ed and Ee is decreased when f’c increases. It was found that the differences between Ed and Ee in this study are greater than the differences between Ed and Ee in BS 8110: 2 and the other studies.

کلیدواژه‌ها [English]

  • nano materials
  • Compressive strength
  • Self-Compacted Concrete
  • static elastic modulus
  • dynamic elastic modulus
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