معرفی پارامتر فیزیکو-مکانیکی برای برآورد دوام سنگ‌های تراورتن ‌ در برابر هوازدگی نمک

نوع مقاله : مقاله پژوهشی

نویسندگان

1 استادیار بخش زمین‌شناسی، دانشکده علوم پایه، دانشگاه لرستان، خرم آباد

2 استادیار،‌ گروه زمین‌شناسی مهندسی دانشکده علوم پایه دانشگاه تربیت مدرس nikudelm@yahoo.com

3 استاد گروه زمین‌شناسی مهندسی، دانشکده علوم پایه، دانشگاه تربیت مدرس، تهران

چکیده

دوام سنگ­ها در برابر عوامل مخرب محیطی از مهمترین موضوعات مرتبط با انتخاب سنگ برای استفاده در سازه­های مهندسی به ویژه سنگ نمای ساختمان­ها می­باشد. تبلور نمک­های محلول یکی از مهمترین عوامل هوازدگی در طبیعت است که می­تواند بر خصوصیات مکانیکی سنگ (مانند مقاومت فشاری تک محوری و مقاومت کششی برزیلین) تاثیر بگذارد و در طول زمان باعث زوال­پذیری و کاهش دوام آن شود. در این پژوهش پارامتر فیزیکو-مکانیکی معرفی شده است که می­تواند خصوصییات مکانیکی سنگ­ها و در نتیجه دوام آن­ها را در برابر هوازدگی نمک با دقت و صحت مناسب برآورد کند. به منظور رسیدن به اهداف پژوهش، 15 نمونه تراورتن از معادن مختلف ایران انتخاب شد. از تراورتن­ها نمونه­ها و مغزه­های لازم برای تعیین خصوصیات فیزیکی (جذب آب، میانگین قطر حفره­های نمونه­ها) و خصوصیات مکانیکی (مقاومت فشاری تک محوری و کششی برزیلین) تهیه و مقادیر این خصوصیات تعیین شد. سپس مقادیر پارامتر فیزیکو-مکانیکی که بر اساس ترکیبی از جذب آب، میانگین قطر حفره­ها و خصوصیات مکانیکی می­باشد، محاسبه شد. با انجام آنالیزهای رگرسیون دو متغیره، رابطه بین مقادیر پارامتر فیزیکو-مکانیکی با مقادیر مقاومت فشاری تک محوری و کششی برزیلین بعد از آزمایش هوازدگی نمک بررسی و مناسبترین روابط برای برآورد دوام نمونه­های مورد مطالعه با استفاده از پارامتر فیزیکو-مکانیکی در برابر هوازدگی نمک ارائه شده است. نتایج نشان دهنده دقت و صحت مناسب پارامتر فیزیکو-مکانیکی برای برآورد دوام نمونه­های مورد مطالعه می­باشد. در نهایت با استفاده از پارامتر فیزیکو-مکانیکی معرفی شده در پژوهش حاضر، می­توان از انجام آزمایش زمانبر و پرهزینه هوازدگی نمک صرفنظر کرد.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Introducing the physico-mechanical parameter for estimating the durability of travertine stones against weathering salt

نویسندگان [English]

  • Amin Jamshidi 1
  • Mohammadreza Nikudel 2
  • Mashaallah Khamehchian 3
1 Assistant Professor of Engineering Geology , Department of Geology, Lorestan University, Khoramabad
2 Assistant professor, Department of Engineering Geology, Tarbiat Modares University, nikudelm@modares.ac.ir
3 Associate Professor of Engineering Geology , Department of Engineering Geology, Tarbiat Modares University, Tehran
چکیده [English]

The durability of stone against environmental degradation factors is one of the most important issues related to stone selection for use in engineering structures, in particular stone stones. The crystallization of soluble salts is one of the most important weathering factors in nature, which can affect the mechanical properties of rock (such as uniaxial compressive strength and Brazilian tensile strength) and, over time, can decay and reduce its durability. In this research, a physico-mechanical parameter has been introduced that can assess the mechanical properties of rocks and thus their durability against salt weathering with accurate accuracy. To achieve the research objectives, 15 travertine samples were selected from different mines in Iran. Travertine samples were prepared to determine the physical properties (water absorption, mean pore diameter) and mechanical properties (uniaxial compressive strength and Brazilian tensile strength). Then, the physico-mechanical parameter was calculated, based on the combination of water absorption, mean diameter of the pores and mechanical properties. By performing bivariate regression analysis, the relationship between physico-mechanical parameter with uniaxial compressive strength and Brazilian tensile strength after the salt weather test was investigated and the most suitable relationships for estimating the durability of the samples using a physico-mechanical parameter against weathering is presented. The results show the correct accuracy of the physico-mechanical parameter for estimating the durability of the studied samples. As a result, the Physico-Mechanical Parameter avoids performing a salt crystallization test, which is time-consuming and expensive.
The durability of stone against environmental degradation factors is one of the most important issues related to stone selection for use in engineering structures, in particular stone stones. The crystallization of soluble salts is one of the most important weathering factors in nature, which can affect the mechanical properties of rock (such as uniaxial compressive strength and Brazilian tensile strength) and, over time, can decay and reduce its durability. In this research, a physico-mechanical parameter has been introduced that can assess the mechanical properties of rocks and thus their durability against salt weathering with accurate accuracy. To achieve the research objectives, 15 travertine samples were selected from different mines in Iran. Travertine samples were prepared to determine the physical properties (water absorption, mean pore diameter) and mechanical properties (uniaxial compressive strength and Brazilian tensile strength). Then, the physico-mechanical parameter was calculated, based on the combination of water absorption, mean diameter of the pores and mechanical properties. By performing bivariate regression analysis, the relationship between physico-mechanical parameter with uniaxial compressive strength and Brazilian tensile strength after the salt weather test was investigated and the most suitable relationships for estimating the durability of the samples using a physico-mechanical parameter against weathering is presented. The results show the correct accuracy of the physico-mechanical parameter for estimating the durability of the studied samples. As a result, the Physico-Mechanical Parameter avoids performing a salt crystallization test, which is time-consuming and expensive.
 

کلیدواژه‌ها [English]

  • Brazilian tensile strength
  • Durability
  • Physico-Mechanical Parameter
  • Uniaxial compressive strength
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