ارزیابی آزمایشگاهی بهبود خواص مکانیکی خشت با استفاده از الیاف خرما

نوع مقاله : مقاله پژوهشی

نویسندگان

1 دانشکده عمران/دانشگاه یزد

2 استادیار، دانشکده عمران، دانشگاه یزد، یزد، ایران

3 عضو هیات علمی / دانشگاه یزد

چکیده

 مقاومت فشاری نسبتاً پایین و نیز مقاومت کششی ناچیز به همراه عدم شکل­ پذیری کافی از ضعف‌های اساسی ساختمان‌های گلین به شمار می‌رود که باعث آسیب ­پذیری آن‌ها در برابر بارهای ثقلی و جانبی از جمله بار زلزله می‌گردد. در این مطالعه آزمایشگاهی امکان استفاده از الیاف درخت خرما به عنوان یک مسلح کننده طبیعی جهت بهبود خواص مکانیکی خشت شامل مقاومت فشاری، مقاومت کششی و شکل­­ پذیری مورد بررسی قرار می‌گیرد. بدین منظور بلوک ­های خشتی در ابعاد 50 × 200 × 200 میلی­متر مکعب و با افزودن الیاف خرما به مقدار 0، 0/25، 0/5، 0/75 و 1% وزنی خاک ساخته می ­شود. مقاومت فشاری از نمونه‌های مکعبی به ابعاد 50 × 50 × 50 میلی­ متر مکعب که از بلوک­ های خشت­ کامل بریده شده و شکل‌پذیری نمونه­ ها نیز با استفاده از منحنی­ های تنش - کرنش فشاری حاصل محاسبه می‌شود. به منظور ارزیابی مقاومت کششی نمونه‌ها، از آزمایش خمش سه نقطه‌ای بر روی نمونه ­های مکعب مستطیلی به ابعاد 50 × 50 × 200 میلی­ متر مکعب که از بلوک­ های خشت کامل بریده شده، استفاده می‌شود. نتایج به دست آمده نشان می­ دهد افزودن مقدار 0/25% الیاف خرما می­ تواند مقاومت فشاری خشت را تا حدود 50% و افزودن 1% الیاف مقاومت کششی آن را تا بیش از 100% نسبت به نمونه شاهد افزایش دهد. همچنین بر پایه آنالیز نتایج به دست آمده از آزمایش­ های فشاری و خمش سه نقطه ­ای، روابط تحلیلی برای تخمین مقاومت فشاری و کششی مصالح خشتی مسلح شده با الیاف خرما (با مقدار الیاف 0 تا 1%) پیشنهاد می­ شود.

کلیدواژه‌ها

موضوعات

عنوان مقاله [English]

Experimental evaluation into improving the mechanical properties of adobe using palm fibers

نویسندگان [English]

  • Hossein Mohammadi 1
  • Abolfazl Eslamihassanabadi 2
  • Reza Morshed 3
1 Department of Civil Engineering/Yazd University
2 Assistant Professor, Dept. of Civil Engineering, Yazd University, Yazd, Iran
3 Department of Civil Engineering/Yazd University
چکیده [English]

The relatively low compressive strength and negligible tensile resistance aligned with inadequate ductility are considered as major drawbacks of earthen buildings leading to their vulnerability against the gravity and lateral loading including seismic-induced forces. In this study, the possibility of using palm fibers as a natural reinforcement in order to improve the mechanical properties of adobe bricks including compressive strength, tensile strength and ductility are evaluated. To this end, adobe bricks with dimensions of 200 × 200 × 50 mm3 are made by adding palm fibers of 0, 0.25, 0.5, 0.75, and 1% of soil weight. Compressive properties are determined using cube samples with dimensions of 50 × 50 × 50 mm3 cut from the full-scale adobe bricks while the ductility factor is obtained using the compressive stress-strain curves. To evaluate the tensile strength of specimens, three-point flexural tests are conducted on prismatic specimens of 50 × 50 × 200 mm3 cut from the full-scale adobe bricks. The obtained results indicated adding 0.25% palm fibers can increase the compressive strength of adobe bricks by 50% and adding 1% palm fiber can twice the tensile strength. Further, based on the analysis of the results obtained from the compressive and three-point bending tests, analytical expressions are proposed to estimate the compressive and tensile strengths of adobe bricks reinforced by palm fiber (from 0 to 1%).

کلیدواژه‌ها [English]

  • Adobe
  • Palm fibers
  • Compressive strength
  • Tensile strength
  • Ductility

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نشریه مهندسی عمران امیرکبیر
دوره 54، شماره 6
شهریور 1401
صفحه 2321-2342

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