26796

تاثير جذب CO2 بر خصوصيات مكانيكي خاك هاي اصلاح شده با پوزولان طبيعي

كارشناسي ارشد

مهندسي عمران- ژئوتكنيك

1398

1401/3/31

حميدرضا رازقي

مهندسي عمران

مشكلات زيست‌محيطي و تغييرات اقليمي يكي از مسئله¬هايي مي‌باشد كه امروزه مشكلات مهمي براي بشر ايجاد كرده، يكي از دلايل ايجاد اين مشكل، توليد گاز¬هاي گلخانه¬اي به دليل فعاليت¬هاي بي¬رويه¬ي بشر مي‌باشد. به همين دليل امروزه يكي از چالش¬هاي مهم كه بشر با آن مواجه است، افزايش توليدات گاز¬هاي گلخانه¬اي مثل CO_2 مي‌باشد، در پروژه¬هاي عمراني، يكي از موادي كه همواره هم در فرايند توليد و هم در فرايند مصرف باعث توليد CO_2 مي‌باشد، سيمان است، ازاين‌رو محققين در اين حوزه همواره در تلاشند كه اين ماده را با يك ماده دوستدار محيط‌زيست جايگزين كنند. ژئوپليمر يكي از موادي مي‌باشد كه در سال¬هاي اخير مورد توجه قرار گرفته است. پليمريزاسيون از يك واكنش شيميايي سريع در يك محيط بازي استفاده مي‌كند تا يك زنجيره¬ي شامل Si-O-Al-O را تشكيل دهد. فرايند ژئوپليمراسيون به Al و Si نياز دارد تا در محلول قليايي حل شود. در سيمان¬هاي پرتلند، خاصيت اصلي چسبندگي آن از كلسيم سيليكات هيدراته ناشي مي‌شود (CSH)، در حالي كه در ژئوپليمر اين چسبندگي از شبكه¬ي 3 بعدي آمورف آلومينوسيليكات ناشي مي‌شود. تكنولوژي ژئوپليمر مي¬تواند زباله¬هاي صنعتي كه شامل آلومينوسيليكات هستند، به مواد قابل‌استفاده‌اي تبديل كند. در اين تحقيق هدف بررسي تاثيرات جذب گاز CO_2 بر خصوصيات مكانيكي خاك‌هاي اصلاح شده با پوزولان طبيعي مي‌باشد.

1401/04/28

The effect of CO2 captured on the mechanical properties of soils modified with natural pozzolan

6/21/2023 12:00:00 AM

Geopolymer technology can turn industrial wastes, including aluminosilicates, into usable materials. Solid geopolymer samples alone can be used as CO_2 adsorbents. The finer and more homogeneous the particles that make up the geopolymer and the higher the specific surface area, the higher their CO_2 uptake. Step 1: Gather the available information about natural geopolymers and pozzolans Step 2: Provide the required soil and natural pozzolan and alkaline activator for the initial test Step 3: Perform a preliminary experiment to accurately select the soil with the desired characteristics, using a system that can direct CO_2 into the soil to synthesize high quality geopolymer. To do this, an isolated three-axis cell was used, which is connected to a carbon dioxide gas capsule and is also equipped with a pressure regulator. of In the result section, Uniaxial compressive strength samples made in different percentages of Taftan pozzolans and under different processing conditions that have been exposed to different pressures of carbon dioxide gas are presented, then in the next step the results of XRD, FTIR, SEM tests related to The microstructure of the samples is given, and the last part of the calcimeter test results, which determines the amount of carbonate in the soil, is included. As described in the sample construction section, the samples are made in two relative densities of 30% and 80%. The prescribed percentages for the geopolymer precursor were set at three values of 10%, 15% and 20%, moreover 25% (in the case of pressure 1 time and processing time of 7 days) was added to the precursor percentages. It should also be noted that samples containing 10% of pozzolan were made at a relative density of 30%, but due to its weakness and very low resistance compared to other percentages, the specified tests were not performed on them. For the processing part, two states of dry (in the oven and at a temperature of about 50 to 60 degrees) and wet (in the ionolite box with high humidity) were placed in three processing times of 3, 7 and 14 days. In the next step, the samples were placed in the CO_2 gas chamber in 3 pressure modes: 1 bar, 2 bar and 3 bar, and also a number of samples were placed in the atmosphere (laboratory environment) as a control sample.

جذب كربن دي اكسيد , ژئوپليمر , كربناسيون , پوزولان طبيعي , ماسه فيروز كوه , روش زيست-تثبيت سازي , خاكستر آتشفشاني

CO2 Captured , Geopolymer , Carboantion , Natural Pozzolan , firouzkoh sand , bio-stabilized method , Volacanic ash

Armin Geranghadr

Dr. Razeghi