Modares Civil Engineering journal
مهندسی عمران مدرس
MCEJ
Engineering & Technology
http://mcej.modares.ac.ir
1
admin
2476-6763
10.22034
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jalali
1397
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gregorian
2018
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بررسی آزمایشگاهی مولفههای موثر بر خواص مکانیکی و پایایی بتن فوق توانمند با رویکرد اقتصادی
Laboratory Study of Factors Affecting the Mechanical Properties and Durability of High Performance Concrete with the Economic Approach
<span dir="RTL"><span style="font-family:b lotus;"><span style="font-size:10.0pt;">افزایش مقاومت فشاری به بیش از 50 مگاپاسکال، کیفیت و دوام بتن جزء اهداف مهم سند چشم انداز بتن 1404 است. همواره تولید بتن با مقاومت زیاد نیازمند توجه خاص در طرح اختلاط اجزاء، استفاده از مواد مناسب، لزوم بهینه سازی مصرف سیمان و ترکیب مصالح تشکیل دهنده­ی آن بوده است. در این مقاله، نمونه­های مکعبی بتنی طوری تهیه شده­اند که 5 متغیر موثر شامل سه نوع متفاوت منحنی­های دانه بندی درشت دانه و ریزدانه، 3 نوع ابر روان کننده، میکروسیلیس با نسبت های 5، 7 و 12 درصد وزنی سیمان در دو رده­ی مقاومتی مختلف با عیار سیمان متفاوت، تاثیر عیار سیمان بصورت 375، 400 و 425 کیلو گرم بر متر مکعب با نسبت آب به سیمان ثابت و تاثیر افزودن فیلر بر مشخصات مکانیکی، دوام و اقتصاد طرح بطور کامل بررسی شده است. در این آزمایش­ها نسبت آب به سیمان برای مقایسه نتایج، ثابت در نظر گرفته شده است. نتایج نشان می­دهند که متغیرهای درنظر گرفته شده بر مقاومت فشاری بتن­های پرمقاومت بسیار تاثیر گذار بوده و استفاده از حالات بهینه­ی طرح های فوق می­تواند سبب بهبود مشخصات مکانیکی بتن شوند به گونه­ای که با بهینه سازی اجزاء مورد استفاده می­توان با عیار سیمانی 400</span></span></span><span dir="RTL"><span style="font-family:b lotus;"><span style="font-size:10.0pt;"> کیلوگرم در متر مکعب، به ساخت بتن­های بسیار توانمند با رویکردی اقتصادی دست یافت. </span></span></span>
The most important aims in Concrete-1404 are compressive strength more than 50 Mpa, quality and durability. These items seems to ignore before that in Iran. The high strength concrete production always needs to use suitable materials, attention to mix design, optimizing cement percentage and other component in concrete. For reaching to a trustable mix designs and aspects of high strength concrete, it needs to be evaluated by a complete investigation which can provide all three aspects of strength, workability and durability of a 1404-concrete. In this paper, cubic concrete samples are made in a way which is affected by 5 variables. These 5 Effective ranges are included: 1) Three different types of coarse and fine aggregate gradation curves which are made of finnest through roughest grading of aggregates according to ASTM C33. 2) Three types of high water reducers used in exact same mix design to compare the effects of these 3 different kind of superplasticizers on high strength concrete. These three type are grade F with polycarboxilate-ether based, grade F with sodium naphthalene solphonate based and grade G as a super high water reducer admixture. 3) Effects micro silica with 5, 7 and 12 percentage of total cement amount are added to compare the results on high strength concrete. 360 and 410 kg cement per m3 are used in source concrete mixtures as the regular using amount in practical projects in Iran. 4) The effect of cement content, with fixed w/c and 5% micro silica, which are between 375 through 425 kg/m3. And 5) the effects of adding filler which are thoroughly investigated on mechanical properties, durability and economy plan. There are 20 mix design in 6 groups are prepared with total cementitious materials from 360 to 425 kg/m3. To compare the results, in these experiments the water cement ratio has been fixed to 0.25. The tests used in experiments were compressive strength test by 3000 KN hydraulic compressor and 24 hours water absorption test. The mechanical and durability properties are recognized by these tests. For evaluating fresh concrete properties, slump test was done. Economical aspect is studied and compared by comparing price of materials and content that are used in each mixture. The results show that the variables were impressively affected the compressive strength in high strength concrete. Using optimum conditions of the studied mixture design can improve the mechanical properties of concrete. By optimizing components in mixture design, high strength concrete can be made even with cement content of 400 kg per cubic meter. The 360 and 410 kg cement with adding 5% micro silica showed the best improving in compressive strength. Enhancing cement more than 400 kg results to decrease compressive strength. High water reducers with polycarboxilate ether based show better results in mechanical and fresh concrete properties and also in economical aspect. Adding filler to mixture led to decrease compressive strength and increase durability, however it had no effects on economical properties of high strength concrete. It can be concluded that aggregate grading can still lead to changes in compressive strength, durability and workability of HSC.
بتن پرمقاومت, دانهبندی مصالح سنگی, فوق روانکننده, میکروسیلیس, مقاومت فشاری.
HSC, grading of aggregate, superplasticizer, Microsilica, compressive strength
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http://mcej.modares.ac.ir/browse.php?a_code=A--39633-356&slc_lang=other&sid=16
سجاد
براری
100319475328460094662
100319475328460094662
Yes
دانشگاه رازی کرمانشاه
شهاب
عباسی
100319475328460094663
100319475328460094663
No
دانشگاه آزاد واحد شوشتر
مهدی مهدوی عادلی3
مهدوی عادلی
100319475328460094664
100319475328460094664
No
دانشگاه آزاد واحد شوشتر
مهدی
چینی
100319475328460094665
100319475328460094665
No
دانشگاه تهران