بررسی امکان بهبود برخی از مشخصات مکانیکی بتن پاششی مقاومت بالای الیافی در دو روش تر و خشک

نوع مقاله : پژوهشی اصیل (کامل)

نویسندگان
1 دانشگاه صنعتی سهند
2 دانشکده مهندسی عمران دانشگاه صنعتی سهند تبریز
3 دانشکده مهندسی عمران، دانشگاه صنعتی سهند تبریز
4 مسئول کارگروه مهندسی عمران و معماری،سازمان علمی، پژوهشی و فناوری استان البرز
5 مربی دانشکده مهندسی عمران، دانشگاه صنعتی سهند تبریز
چکیده
استفاده از بتن پاششی به صورت فزآینده‌ای رو به رشد است. با توجه به پیشرفت‌های صورت گرفته در زمینه تجهیزات و افزودنی‌ها، در صنعت ساخت‌وساز، نیاز به مقاومت بالا در بتن پاششی به طور قابل توجهی احساس می‌شود. به کارگیری ‌بتن پاششی مقاومت بالای الیافی، در پایدارسازی گودها و شیروانی‌ها، مقاوم سازی سازه‌های بنایی و بتنی و سازه‌های زیرزمینی باعث بهبود کیفیت، چسبندگی و افزایش سرعت کار می‌گردد. همچنین با افزایش مقاومت و به تبع آن با کاهش ابعاد مقاطع، طرح‌ها اقتصادی‌تر می‌گردند. در این تحقیق با استفاده از طرح اختلاط‌های متفاوت، اثرات دانه‌بندی مصالح و مواد افزودنی از قبیل میکروسیلیس، فوق روان کننده، آنی‌گیر و الیاف فولادی بازیافتی میکرو بر روی مقاومت و عملکرد بتن پاششی به صورت آزمایشگاهی و میدانی به دو روش پاشش تر و خشک بررسی شدند. براساس نتایج دستیابی به بتن پاششی مقاومت بالا در روش پاشش‌تر، از امکان پذیری بالاتری برخوردار بوده و مقاومت فشاری28 روزه 987 کیلوگرم بر سانتی متر مربع در بتن پاششی الیافی تر حاصل گردید که به ترتیب مقاومت فشاری و جذب انرژی80 و 77 درصد نسبت به شاتکریت الیافی معمولی تر افزایش یافت. همچنین بر اساس آزمایش‌های چقرمگی استفاده از الیاف فولادی بازیافتی میکرو، در جلوگیری از گسترش ریز ترک‌ها و کنترل تغییر شکل‌ها، نقش موثری داشته و در بتن پاششی مقاومت بالا موجب شد، به ترتیب مقاومت فشاری و جذب انرژی 28 و 97 درصد نسبت به همان طرح بدون استفاده از الیاف افزایش یابد.

کلیدواژه‌ها

موضوعات


عنوان مقاله English

Investigating the possibility of improving some of the mechanical characteristics of fiber-reinforced high-strength shotcrete in two wet and dry methods

نویسندگان English

mohammadhossein ahmadian khameneh 1
hassan afshin 2
Mehrdad Imami Tabrizi 3
yasser alilou Kisjini 4
Gholamreza Qudsi Sharif 5
1 Student of Sahand University of Technology
2 Associate Professor, Faculty of Civil Engineering, Sahand University of Technology, Tabriz
3 Assistant Professor, Faculty of Civil Engineering, Sahand University of Technology, Tabriz
4 Head of Civil Engineering and Architecture Working Group, Scientific, Research and Technology Organization of Alborz Province
5 Instructor of Faculty of Civil Engineering, Sahand University of Technology
چکیده English

Shotcrete, a pneumatically sprayed concrete mixture, has gained significant popularity in the construction industry due to its versatility and adaptability. However, the demand for high-strength shotcrete has intensified, driven by advancements in equipment and admixtures. Fiber-reinforced high-strength shotcrete (FRHSS) offers enhanced quality, adhesion, and construction speed, making it ideal for stabilizing excavations and slopes, strengthening masonry and concrete structures, and reinforcing underground structures. Additionally, the increased strength allows for reduced section dimensions, leading to more economical designs.



This research investigates the effects of aggregate gradation and admixtures, including micro silica, superplasticizer, accelerator, and micro recycled steel fibers (MRSFs), on the strength and performance of FRHSS. The study employs wet-mix and dry-mix shotcrete methods, examining the properties through laboratory and field experiments.



The results demonstrate that achieving high-strength shotcrete is more feasible with the wet-mix method. Fiber-reinforced wet-mix shotcrete attained a 28-day compressive strength of 987 kg/cm², representing an 80% and 77% increase in compressive strength and energy absorption, respectively, compared to conventional fiber-reinforced wet-mix shotcrete. Furthermore, fracture toughness tests revealed that MRSFs effectively prevent microcrack propagation and control deformations. FRHSS incorporating MRSFs exhibited a 28% and 97% increase in compressive strength and energy absorption, respectively, compared to the corresponding mix without fibers.

کلیدواژه‌ها English

Shotcrete
Absorbing energy
steel fibers
Flexural toughness
High-strength
Accelerator
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