تقویت عملکرد خمشی چندسازۀ چوبی با لایه‌های متقاطع (CLT) ساخته‌شده از صنوبر و پیچ با ورق آلومینیوم و الیاف شیشه

نوع مقاله : مقاله پژوهشی

نویسندگان

1 استادیار گروه منابع طبیعی، دانشکدۀ کشاورزی و منابع طبیعی، دانشگاه محقق اردبیلی، اردبیل

2 دانشجوی کارشناسی گروه منابع طبیعی، دانشکدۀ کشاورزی و منابع طبیعی، دانشگاه محقق اردبیلی، اردبیل

چکیده

در این پژوهش، تقویت عملکرد خمشی CLT سه‌لایۀ ساخته‌شده از صنوبر (populous alba)، چسب و پیچ پانلی برای اعمال فشار بررسی شد. متغیرهای بررسی‌شده شامل نوع تقویت‌کننده (ورق آلومینیوم و الیاف شیشه) و آرایش قرارگیری تقویت‌کننده (آرایش 1 (در قسمت پایین (کششی))، آرایش 2 (در قسمت پایین (کششی) و بالا (فشاری))، آرایش 3 (در پایین، بالا و بین دو لایۀ پایین) و آرایش 4 (در پایین، بالا و بین لایه‌ها) بودند. آزمون خمش براساس ASTM D4761  و دستگاه اینسترون انجام گرفت. نتایج نشان داد که بیشترین MOR و MOE مربوط به جهت طولی پانل‌های CLT تقویت‌شده با ورق آلومینیوم با آرایش 3 و کمترین MOR و MOE مربوط به جهت عرضی پانل‌های CLT تقویت‌شده با الیاف شیشه با آرایش 1 بود. با تقویت CLT با ورق آلومینیوم، MOR و MOE در جهت عرضی CLT به‌ترتیب 1/195  و 6/344 درصد و در جهت طولی 3/89 و 8/50 درصد نسبت به نمونۀ شاهد افزایش یافت. در پی تقویت CLT با الیاف شیشه، MOR و MOE در جهت عرضی پانل CLT به‌ترتیب 8/42 و 3/21 درصد و در جهت طولی 1/46  و7/12 درصد نسبت به نمونۀ شاهد افزایش یافت. MOR و MOE نمونه‌های تقویت‌شده با ورق آلومینیوم بیشتر از نمونه‌های تقویت‌شده با GFRP بود. تقویت CLT سبب تغییر مد شکست از ترد به شکست نرم شد و به‌تبع آن عملکرد خمشی آنها بهبود یافت.

کلیدواژه‌ها

عنوان مقاله [English]

Reinforcement of flexural performance of screwed cross laminated timber (CLT) panels constructed of poplar by aluminum sheet and glass fiber reinforced polymer wrap

نویسندگان [English]

  • Akbar Rostampour Haftkhani 1
  • Ali Shokrvand Shakiba 2
1 Assist., Prof., Department of Natural Resources, Faculty of Agriculture and Natural Resources, University of Mohaghegh Ardabili, Ardabil, I.R. Iran
2 B.Sc., Department of Natural Resources, Faculty of Agriculture and Natural Resources, University of Mohaghegh Ardabili, Ardabil, I.R. Iran
چکیده [English]

In this study, flexural reinforcement of 3-layer screwed CLT made of poplar (Populous alba) and polyurethane glue was investigated. Static bending test was performed by Instron according to ASTM D4761. The variables of this study were types of reinforcing (aluminum sheet and glass fiber reinforcement polymer (GFRP) wrap) and arrangements of reinforcers (no.1: bonded on the bottom (tension) side; no.2: bonded on the bottom and top (tension and compression side); no.3: bonded on the bottom, top and between two bottom layers; no.4: bonded on the bottom, top and among layers). The results showed that the higher MOR and MOE were related to major direction of CLT reinforced with aluminum with configuration of no.1. The lower MOR and MOE were observed in minor direction of CLT reinforced with GFRP with configuration of no.1. The increasing percentage of the MOR and MOE in minor direction of CLT reinforced with aluminum were 195.1 and 344.6% and in major direction of them were 89.3 and 50.8%, respectively in comparison with control specimens. When CLT panel were reinforced with GFRP, the increasing percentage of MOR and MOE in the minor direction of CLT were 42.8 and 21.3% and in major direction of CLT were, respectively 46.1 and 12.7% in comparison with control specimens. The results showed that MOR and MOE of CLT reinforced with aluminum sheet were higher than those reinforced with GFRP wraps. Failure modes of CLT were changed by reinforcing from brittle to ductile and consequently increased their flexural strength.

کلیدواژه‌ها [English]

  • Mechanical fastener
  • GFRP wrap
  • flexural performance reinforcement
  • cross-laminated timber (CLT)
  • poplar
  • aluminum sheet

مراجع

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نشریه جنگل و فرآورده های چوب
دوره 73، شماره 3
آبان 1399
صفحه 317-331

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