تاثیر حجم خمیر مواد سیمانی و استفاده از زئولیت بر خواص بتن خودتراکم

نوع مقاله : مقاله پژوهشی

نویسندگان

1 دانشجوی کارشناسی ارشد سازه، گروه مهندسی عمران ، واحد علوم و تحقیقات ، دانشگاه آزاد اسلامی تهران ، ایران

2 عضو هیات علمی /مرکز تحقیقات راه مسکن و شهرسازی

3 عضو هیئت علمی مرکز تحقیقات راه و مسکن شهرسازی

4 عضو هیئت علمی دانشگاه علوم و تحقیقات تهران

چکیده

بتن خودتراکم امتیازهای ویژه­ای از جمله قابلیت روانی و پرکنندگی زیاد، بی نیازی به لرزاندن و تراکم بهتر را نسبت به بتن معمولی دارد، لکن این مزایا معمولاً با افزایش مقدار حجم خمیر مخلوط قابل دستیابی است. از این رو، حجم خمیر بتن‌های خودتراکم یکی از مهمترین مشخصه­های این نوع بتن می­باشد. در این تحقیق، به منظور بررسی خواص تازه و سخت شده بتن خودتراکم با حجم خمیرهای متفاوت، سه عیار مواد سیمانی ( 450، 495 و 540 کلیوگرم بر متر مکعب ) با نسبت آب به مواد سیمانی ثابت ساخته شد. همچنین در عیارهای مواد سیمانی 495 و 540 کیلوگرم بر متر مکعب، به ترتیب 9 و 17 درصد زئولیت جایگزین سیمان شد تا اثر این ماده به عنوان یک پوزولان روی خواث بتن تازه و سخت‌شده بررسی شود. نتایج آزمایش­ها نشان می­دهد که افزایش عیار مواد سیمانی بتن خودتراکم از 450 به 540 کیلوگرم بر متر مکعب در یک نسبت آب به مواد سیمانی ثابت، تأثیر قابل ملاحظه‌ای بر  مقاومت فشاری بتن ندارد، اما جداشدگی را افزایش می‌دهد. همچنین نتایج آزمایش قیف V نشان می‌دهد که این افزایش عیار مواد سیمانی در  نسبت آب به مواد سیمانی برابر، اثر قابل توجهی روی لزجت بتن ندارد اما جایگزین کردن بخشی از سیمان با زئولیت، لزجت بتن خودتراکم را افزایش داده و تاثیر مثبتی بر عدم جداشدگی، مقاومت فشاری و مقاومت الکتریکی بتن دارد.

کلیدواژه‌ها


عنوان مقاله [English]

The effect of cementitious materials paste volume and use of zeolite on the properties of self-compacting concrete

نویسندگان [English]

  • Saeed Khalooee 1
  • Babak Ahmadi 2
  • Azadeh Askarinejad 3
  • Masoud Nekooei 4
1 MSc Student in Civil Engineering,Structural Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran
2 Assistant Professeor, Road, Housing & Urban Development Research Centre, Department of Concrete Technology, Tehran, Iran
3 Assistant Professeor, Road, Housing & Urban Development Research Centre, Department of Construction Materials, Tehran, Iran
4 Department of Civil Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran
چکیده [English]

 
 
Self-compacting concrete (SCC) has advantages such as flowability, filingability and having no need to vibration and better consolidation compared to conventional concrete. However, these benefits are achievable through increasing the volume of paste. Therefore, the volume of SCC paste is one of the most significant parameters in such type of concrete. In this research study, in order to investigate the fresh and hardened properties of SCC mixtures with various paste volume, three levels of cementitious materials (450 kg/m3, 495 kg/m3 and 540 kg/m3) were made keeping w/cm constant. In addition, at cementitious materials content of 450 kg/m3 and 495 kg/m3, natural zeolite was replaced 9% and 17% of cement by weight, respectively to study the influence of this material as a type of pozzolan. The experimental results indicate that increasing the SCC’s cementitious materials at a constant W/CM, does not have considerable effect on compressive strength of concrete, while increases the segregation. The results of V-funnel test show that increasing the cementitious materials content at a constant W/CM, has no prominent impact on viscosity of concrete, however partial replacement of cement by zeolite increases this parameter of SCC and has a positive effect on stability, compressive strength and resistivity.

کلیدواژه‌ها [English]

  • self-compacting concrete
  • paste volume
  • cement content
  • zeolite
 
 
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