اثر گليسرول و استون بر خواص فيزيكي و مكانيكي يك خاك رسي

Effect of Glycerol and Acetone on the physical and mechanical properties of a clay soil

در اﯾﻦ ﭘﮋوﻫﺶ اﺛﺮ دو ﻧﻮع آﻻﯾﻨﺪه ﮔﻠﯿﺴﺮول و اﺳﺘﻮن ﺑﺮ ﺧﻮاص ﻓﯿﺰﯾﮑﯽ و ﻣﮑﺎﻧﯿﮑﯽ ﯾﮏ ﺧﺎك رﺳﯽ ﺑﺎ ﺧﻤﯿﺮاﯾﯽ ﭘﺎﯾﯿﻦ )CL( ﻣﻮرد ﺑﺮرﺳﯽ ﻗﺮار ﮔﺮﻓﺖ. آزﻣﺎﯾﺸﺎت ﺣﺪود آﺗﺮﺑﺮگ، ﺗﺮاﮐﻢ، ﺗﻮرم آزاد، ﺗﺤﮑﯿﻢ، ﻣﻘﺎوﻣﺖ ﺗﮏﻣﺤﻮري و ﺳﯽﺑﯽآر ﺑﺮ روي ﻧﻤﻮﻧﻪﻫﺎﯾﯽ از ﺧﺎك در ﺣﺎﻟﺖ ﻃﺒﯿﻌﯽ و آﻟﻮده ﺷﺪه ﺑﺎ درﺻﺪﻫﺎي ﮔﻮﻧﺎﮔﻮن )15 ،10 و20 درﺻﺪ( از دو ﻣﺎدة آﻻﯾﻨﺪه ﻫﯿﺪروﮐﺮﺑﻨﯽ ﻓﻮق ﺻﻮرت ﭘﺬﯾﺮﻓﺖ. ﻋﻼوه ﺑﺮ اﯾﻦ ﻋﮑﺲﺑﺮداي ﻣﯿﮑﺮوﺳﻮپ اﻟﮑﺘﺮوﻧﯽ روﺑﺸﯽ )SEM( روي ﻧﻤﻮﻧﻪﻫﺎي ﺧﺎك ﻃﺒﯿﻌﯽ و آﻟﻮده ﺷﺪه ﺑﺎ دو ﻣﺎدة ﯾﺎد ﺷﺪه، اﻧﺠﺎم ﺷﺪ. ﻧﺘﺎﯾﺞ ﻧﺸﺎن دادﻧﺪ ﮐﻪ ﺑﺎ اﻓﺰودن ﮔﻠﯿﺴﺮول، ﺣﺪود آﺗﺮﺑﺮگ و درﺻﺪ ﺗﻮرم ﮐﺎﻫﺶ، وﻟﯿﮑﻦ ﭘﺎراﻣﺘﺮﻫﺎي ﺗﺮاﮐﻤﯽ ﺷﺎﻣﻞ وزن واﺣﺪ ﺣﺠﻢ ﺧﺸﮏ ﺑﯿﺸﯿﻨﻪ و رﻃﻮﺑﺖ ﺑﻬﯿﻨﻪ ﺑﻪ ﺗﺮﺗﯿﺐ اﻓﺰاﯾﺶ و ﮐﺎﻫﺶ ﻣﯽﯾﺎﺑﻨﺪ. ﻟﯿﮑﻦ اﻓﺰودن اﺳﺘﻮن ﺑﻪ ﺧﺎك ﺑﺮﺧﻼف ﺗﻐﯿﯿﺮات اﯾﺠﺎد ﺷﺪه ﻧﺎﺷﯽ از اﻓﺰودن ﮔﻠﯿﺴﺮول را ﻧﺸﺎن داد ﺑﻪ ﮔﻮﻧﻪاي ﮐﻪ ﺣﺪود آﺗﺮﺑﺮگ و درﺻﺪ ﺗﻮرم اﻓﺰاﯾﺶ و ﻧﯿﺰ وزن واﺣﺪ ﺣﺠﻢ ﺧﺸﮏ ﺑﯿﺸﯿﻨﻪ ﮐﺎﻫﺶ و رﻃﻮﺑﺖ ﺑﻬﯿﻨﻪ اﻓﺰاﯾﺶ ﯾﺎﻓﺘﻨﺪ ﮐﻪ اﯾﻦ ﺗﻐﯿﯿﺮات اﯾﺠﺎد ﺷﺪه ﻧﯿﺰ ﺗﺎﺑﻌﯽ از درﺻﺪ وزﻧﯽ ﻣﺎدة آﻻﯾﻨﺪه ﺑﻮدﻧﺪ. ﻋﻼوه ﺑﺮ اﯾﻦ ﻧﺘﺎﯾﺞ ﻧﺸﺎن دادﻧﺪ ﮐﻪ ﻣﻘﺎوﻣﺖ و ﺳﯽﺑﯽآر )ﻇﺮﻓﯿﺖ ﺑﺎرﺑﺮي( ﺧﺎك آﻟﻮده ﺷﺪه ﺑﺎ ﻫﺮ دو ﻣﺎده ﻧﺴﺒﺖ ﺑﻪ ﺣﺎﻟﺖ ﻃﺒﯿﻌﯽ در ﺧﺎك، روﻧﺪ ﮐﺎﻫﺸﯽ داﺷﺘﻪ ﮐﻪ اﯾﻦ ﮐﺎﻫﺶ در ﺧﺎكﻫﺎي ﺣﺎوي ﮔﻠﯿﺴﺮول ﺑﯿﺸﺘﺮ ﺑﻮده اﺳﺖ. ﻧﺘﺎﯾﺞ آزﻣﺎﯾﺸﺎت ﺗﺤﮑﯿﻢ ﻧﯿﺰ ﻧﺸﺎن دادﻧﺪ ﮐﻪ ﻣﻘﺎدﯾﺮ ﻧﺸﺎﻧﮥ ﻓﺸﺮدﮔﯽ )Cc( و ﻧﺸﺎﻧﮥ ﺗﻮرم )Cs( ﻣﺴﺘﻘﻞ از درﺻﺪ آﻻﯾﻨﺪه ﻣﯽﺑﺎﺷﻨﺪ. ﻫﻤﭽﻨﯿﻦ ﻧﺘﺎﯾﺞ SEM ﻧﺸﺎن داد ﮐﻪ ﺗﻐﯿﯿﺮات ﻧﺎﺷﯽ از دو آﻻﯾﻨﺪة ﯾﺎد ﺷﺪه در وﯾﮋﮔﯽﻫﺎي ﻓﯿﺰﯾﮑﯽ و ﻣﮑﺎﻧﯿﮑﯽ ﺧﺎك، ﻧﺎﺷﯽ از ﺗﻐﯿﯿﺮات اﯾﺠﺎد ﺷﺪه در ﺳﺎﺧﺘﻤﺎن ﺧﺎك اﺳﺖ و ﺗﺄﺛﯿﺮ آﻧﻬﺎ ﺑﺮ وﯾﮋﮔﯽﻫﺎي ﺧﺎك ﻣﻮرد اﺳﺘﻔﺎده ﯾﮑﺴﺎن ﻧﻤﯽﺑﺎﺷﺪ.

In this research work the effect of glycerol and acetone on the properties of a clay soil with low plasticity (CL) was studied through experimental tests. Contaminated soil was prepared by mixing 10, 15 and 20% pure glycerol or acetone with soil. A set of experimental tests including Atterberg limits, compaction, free swelling, Unconfined Compressive Strength (UCS), California Bearing Ratio (CBR), consolidation tests and Scanning Electron Microscopy (SEM) were conducted on uncontaminated and contaminated soil. The results showed that the effect of glycerol on contaminated soil was a reduction of Atterberg Limits, Free Swelling, optimum water content and increasing maximum dry unit weight but the effect of acetone was in the opposite trend of glycerol. These variations in the behaviors of soil were the function of percent of glycerol or acetone. In addition, the results indicated that both glycerol and acetone cause the reduction in the values of compressive strength and CBR number of soil but the reduction due to glycerol was more than the acetone. The results of consolidation test showed that the values of compression index (Cc) and swelling index (Cs) were independent of the percent of chemical fluids. The SEM results also reveal that these two contaminations cause some variations in the physical and mechanical properties of a clay soil becase of changing the structure of soil and the effect of these contaminations on the properties of soil was not the same.