بهبود دوام و مدول الاستیسیته خاک‌های آلوده به نفت در چرخه‌های تر-خشک با استفاده از تثبیت با مواد سنتی

اگرچه مطالعات پیشین به‌طورگسترده، رفتار مقاومتی خاک آلوده به نفت را بررسی کرده‌اند، اما هنوز درک دقیقی از دوام خاک آلوده به نفت در برابر چرخه های تر- خشک وجود ندارد. برای پُرکردن خلا علمی مذکور، پژوهش حاضر بر روی ویژگی های دوام خاک های آلوده به نفت متمرکز شده است. مجموعه‌ای از آزمایش‌های آزمایشگاهی برای ارزیابی تراکم، دوام، و آنالیزهای ریزساختاری انجام شده است. برای این منظور، خاک در غلظت‌های 4، 7، و 10 درصد به نفت آلوده شد. سپس در درصدهای 0، 3، 6، و 9 به‌طورجداگانه با آهک و سیمان تثبیت شد. نتایج نشان دادند که با افزایش درصد نفت در خاک آلوده، مقادیر بیشینه‌ی وزن مخصوص خشک خاک و درصد رطوبت بهینه کاهش یافته است. بیشترین دوام‌ها مربوط به نمونه ‌ی حاوی 4٪  نفت و 9٪ سیمان، و نمونه‌ی حاوی 7٪ نفت و تثبیت‌شده با 6٪ آهک پس از گذراندن 6 چرخه‌ی تر- خشک بوده است. تصاویر میکروسکوپی نشان داده است که استفاده از سیمان و آهک به‌عنوان عوامل تثبیت کننده منجر به ساختار متراکم‌تر خاک آلوده به نفت شده است.

enhancing the durability and elastic modulus of oil-contaminated soils in wet-dry cycles through stabilization with traditional materials

considering that the infrastructures in different regions experience different weather cycles that can lead to the creation of minor surface cracks to be noticeable, it is necessary to understand the durability behavior of soils. although previous studies have extensively investigated the strength behavior of oil-contaminated soil, there is still no accurate understanding of the durability of oil-contaminated soil against wet-dry cycles. to fill these gaps, this research is focused on the durability characteristics of oil-contaminated soils. for this purpose, a series of laboratory tests were conducted to evaluate compaction, durability and microstructural analyses. in that regard, the soil was contaminated with oil in concentrations of 4, 7 and 10% and then stabilized with lime and cement in concentrations of 0, 3, 6 and 9% separately. initial laboratory experiments, including atterberg limits and compaction tests, were conducted. subsequently, durability tests were performed to examine wet-dry cycles in 1, 3, and 6 cycles on oil-contaminated soil samples, as well as those stabilized with cement and lime. the results demonstrated that the highest durability was observed in the samples containing 4% oil and 9% cement in the 6th cycle, showing a 42% increase in resistance compared to a similar sample with the same percentage of oil and cement in the 3rd cycle. additionally, the elasticity modulus of the oil-contaminated soil sample with 4% oil and stabilized with 6% lime was 2 times that of the 1st cycle in the 3rd cycle and 2.8 times that of the 3rd cycle in the 6th cycle. microscopic analysis using electron field emission microscopy unveiled that the incorporation of cement and lime as stabilizing agents resulted in a denser and more compact structure of oil-contaminated soil. this comprehensive research endeavor seeks not only to advance the management practices of contaminated soils but also to uphold the conservation of natural resources while offering an alternative solution for the construction of secondary access roads.