fa تأثیر آهک بر بهینه‌سازی خشت خام در مقابل رطوبت تخصصي Special پژوهشي Research <div style="text-align: justify;"><span style="line-height:2;"><span style="font-family:b lotus;"><span style="font-size:11.0pt;">بناها، محوطه&shy;ها و آثار معماری خشتی تاریخی و باستانی متعدد و زیادی در ایران وجود دارد که پراکندگی آن‌ها بیشتر در مناطق گرم و کویری ایران به چشم می&shy;خورد اما در مناطق کوهستانی و بارانی نیز آثار گلی و خشتی فاخری وجود دارد که&nbsp; نیاز به حفاظت و مرمت دارند تا بتوان آن آثار را به همراه پیام&shy;های خفته در آن‌ها به نسل&shy;های آینده منتقل کرد. در مناطق کوهستانی و مناطق بارانی، رطوبت بالا و جمع شدن آب در پای دیوارها و در مناطق کویری و گرم نظیر سیستان بالا بودن سطح آب&shy;های سطحی عامل اصلی آسیب رسیدن به ساختارهای خشتی و دلیل اصلی تخریب بسیاری از آثار معماری خشتی هستند که لازم است برای جلوگیری از تخریب و فرسایش راهکاری مناسب و کاربردی پیدا کرد. بهینه‌سازی مصالح در حفاظت، مرمت و بازسازی بناهای خشتی در سرتاسر جهان یکی از روش‌های مناسب مرمتی برای این‌گونه بناها به‌شمار می&shy;رود. نظر به ویژگی&shy;های کالبدی و شرایط مکانی و محیطی هر بنا، مواد افزودنی مختلفی تا به امروز مورد آزمایش قرار گرفته و به‌کار برده شده‌اند. در این پژوهش آهک به‌عنوان ماده&shy;ای سنتی و بومی که در مناطق دارای رطوبت بالا و بارندگی&shy;های فصلی شدید و تعدادی از بناهای شمال و شمال غرب ایران نیز دارای اصالت کاربردی است به‌عنوان ماده بهینه‌ساز خشت مورد استفاده قرار گرفت. هدف پژوهش حاضر دستیابی به خشتی سازگار با محیطی با شرایط رطوبت بالا (اشباع خشت) و توأم با کیفیات فیزیکی مناسب و مقاومت نسبی در مقابل سایر نیروهای آسیب رسان است. به این منظور پنج نوع خشت با ترکیب&shy;ها 0، 2، 5، 7، و 10 درصد از آهک ساخته شد و مورد آزمایش‌های مقاومت فشاری در شرایط خشک و اشباع، مقاومت سایشی، جذب مویینگی و مقاومت در برابر غوطه&shy;وری قرار گرفتند که نتیجه مطلوب و متناسب باهدف این پژوهش مربوط به خشت ساخته شده با 2 درصد آهک بود.</span></span><br> <br> &nbsp;<br> &nbsp;</span></div> <div style="text-align: justify;"><span style="line-height:2;">The importance and the value of historical buildings and sites and even villages which have adobe houses causes that conservators annually schedule restoration plans and programs to protect the buildings from hazards. This is done because conservation of these memorials is equal to conservation of culture, civilization, heritages of a nation, their architecture, and their lifestyle. There are many damaging factors for an adobe building being always a threat for its skeleton. Causing irreparable harms independently or dependently, moisture is one of the damaging factors for adobe buildings. Optimizing the repairing materials in conservation, repair, and reconstruction of adobe buildings to increase their resistance against moisture and other damaging factors is one of the suitable methods for protecting these buildings worldwide. Until today, many additive materials have been tested and occasionally applied regarding the enhancement of the physical and environmental properties of the buildings. Lime is a conventional locally supplied material, had been originally used in areas with high humidity and heavy seasonal rainfall. In this research a number of buildings in the North and North West of Iran have been selected as the case study where the lime was used as the adobe optimizer. This research aims to find a mix of adobe which is compatible with the highly humid environment (saturated adobe) as well as having high physical quality and a relative strength against other damaging forces. Now, the question is that by adding lime to soil as a traditional material that absorbs water and is resistant to moisture, can it be possible to increase the stability of these adobe against moisture, as well as their physical properties to keep compressive resistance and abrasion resistance? The research hypothesis suggests that because of low adhesion and poor bonding between lime and soil and low humidity in open spaces, it is likely that by adding lower percentages of lime, a more favorable result can be achieved<span dir="RTL">.</span><br> &nbsp;For this aim, five mix of adobe were made containing 0, 2, 5, 7 and 10 percentage of lime. The samples undergone multiple mechanical tests: compressive resistance in dry and saturated condition, abrasion resistance, capillary absorption and resistance to immersion tests. The results show that lime is affective on physical properties of adobe in such a way that by increasing the amount of lime aforementioned, the compressive strength and abrasion resistance decreases by a significant amount. Capillary test results show that, the increase in the amount of lime in the mix causes the increase in the speed of capillary absorption. This characteristic of lime causes using preparing adobes having lime in reconstruction of walls be an ideal solution to conserving the old&nbsp; internal wall adobes. This is because the exposure of water and moisture are absorbed by this kind of adobe due to the higher level of lime concentration in the mix portion and the main old structure of the wall absorbs the minimum amount of the water and remains safe from abrasion. Based on the results of pressure resistance test on the wet and dry adobe samples and also their resistance against immersion, only 2% added lime cause to keep the physical resistance of adobe compares to the other samples, impressively. According to the results of the tests done in this research and its purpose, among tested adobe samples, the sample number 2 having 2<span dir="RTL">%</span> added lime is estimated as the best optimized sample. In this way, its resistance to compressive and abrasion is higher than other lime samples, as well as its resistance to water immersion and its compressive strength after soaking from all specimens, even the lime sample was higher This optimization of the crude clay and its resistance to water saturation conditions is the same as the desired result and the purpose that this research seeks to do.<br> &nbsp;</span></div> خشت خام‌, آهک, بهینه‌سازی, مقاومت فشاری. جذب مویینگی, مقاومت سایشی, غوطه‌وری adobe, lime, optimization, pressure resistance, capillary absorption, abrasion resistance, immersion 115 124 http://jhre.ir/browse.php?a_code=A-10-3296-1&slc_lang=fa&sid=1 kaveh Bahramzadeh کاوه بهرام زاده kaveh.bahramzadeh@gmail.com 100319475328460016553 100319475328460016553 Yes M.A. Historic Conservation and Restoration of Cultural Objects کارشناس‌ارشد مرمت اشیای تاریخی و فرهنگی Alireza Razeghi علی رضا رازقی 100319475328460016554 100319475328460016554 No Islamic Architecture; PhD- Conservation and Restoration, Art University of Tehran دکترای معماری اسلامی- حفاظت و مرمت، عضو هیئت‌علمی دانشگاه هنر، تهران Najme Khatoon Miri نجمه خاتون میری 100319475328460016555 100319475328460016555 No M.A. Historic Conservation and Restoration of Cultural Objects (faculty member of University of Zabol) کارشناس ارشد حفاظت و مرمت اشیای فرهنگی و تاریخی، مربی و عضو هیئت‌علمی دانشگاه زابل