ارزیابی آزمایشگاهی و بررسی تحلیلی روسازی بتن غلتکی تقویت شده با الیاف پلی پروپیلن و پودر متاکائولن

ﻫﺪف از اﯾﻦ ﭘﮋوﻫﺶ، ﺑﺮرﺳﯽ آزﻣﺎﯾﺸﮕﺎﻫﯽ و ﺗﺤﻠﯿﻞ رﻓﺘﺎر روﺳﺎزی ﺑﺘﻦ ﻏﻠﺘﮑﯽ ﺗﻘﻮﯾﺖﺷﺪه ﺑﻪ ﮐﻤﮏ اﻟﯿﺎف ﭘﻠﯽﭘﺮوﭘﯿﻠﻦ و ﭘﻮدر ﻣﺘﺎﮐﺎﺋﻮﻟﻦ ﻣﯽﺑﺎﺷﺪ. ﺑﻪ ﻣﻨﻈﻮر ارزﯾﺎﺑﯽ اﯾﻦ ﻫﺪف، 16 ﻃﺮح اﺧﺘﻼط ﻣﺘﻔﺎوت ﺳﺎﺧﺘﻪ ﺷﺪ. در اﯾﻦ ﻃﺮحﻫﺎ، اﺛﺮ اﺳﺘﻔﺎده از اﻟﯿﺎف ﭘﻠﯽﭘﺮوﭘﯿﻠﻦ در ﻣﻘﺎدﯾﺮ ﺻﻔﺮ، 0/1 ،0/05 و 0/2 درﺻﺪ ﺣﺠﻤﯽ ﺳﯿﻤﺎن و ﭘﻮدر ﻣﺘﺎﮐﺎﺋﻮﻟﻦ در ﻣﻘﺎدﯾﺮ ﺻﻔﺮ، 7/5، 15 و 22/5 درﺻﺪ وزﻧﯽ ﺳﯿﻤﺎن ﺑﻪ ﺻﻮرت ﻣﺠﺰا و ﻫﻤﺰﻣﺎن در ﺑﺘﻦ ﻏﻠﺘﮑﯽ ﺑﺮرﺳﯽ ﮔﺮدﯾﺪ. آزﻣﺎﯾﺶﻫﺎی ﻣﻘﺎوﻣﺖ ﻓﺸﺎری، ﻣﻘﺎوﻣﺖ ﮐﺸﺸﯽ و ﺟﺬب آب روی ﺗﻤﺎﻣﯽ ﻧﻤﻮﻧﻪﻫﺎ اﻧﺠﺎم ﺷﺪ. ﻧﺘﺎﯾﺞ ﺑﺮرﺳﯽ ﻧﺸﺎﻧﮕﺮ وﺟﻮد ﺑﯿﺸﺘﺮﯾﻦ ﻣﻘﺎوﻣﺖ ﻓﺸﺎری در ﻣﺼﺮف ﻫﻤﺰﻣﺎن 0/1 درﺻﺪ اﻟﯿﺎف ﭘﻠﯽﭘﺮوﭘﯿﻠﻦ و 15 درﺻﺪ ﻣﺘﺎﮐﺎﺋﻮﻟﻦ اﺳﺖ. در اﯾﻦ ﺗﺮﮐﯿﺐ، ﻣﻘﺎوﻣﺖ ﻓﺸﺎری 7 و 28 روزه ﻧﺴﺒﺖ ﺑﻪ ﻧﻤﻮﻧﻪ ﻣﺮﺟﻊ ﺑﻪ ﺗﺮﺗﯿﺐ ﺑﻪ ﻣﯿﺰان 51 و 25 درﺻﺪ اﻓﺰاﯾﺶ ﯾﺎﻓﺖ. ﺗﺮﮐﯿﺐ ﻓﻮق، ﺑﯿﺸﺘﺮﯾﻦ اﻓﺰاﯾﺶ )42 درﺻﺪ( در ﻣﻘﺎوﻣﺖ ﮐﺸﺸﯽ را ﻧﯿﺰ ﻧﺸﺎن داد. ﺑﯿﺸﺘﺮﯾﻦ ﮐﺎﻫﺶ ﺟﺬب آب ﺑﻪ ﻣﯿﺰان 11 درﺻﺪ در ﻣﺼﺮف ﻫﻤﺰﻣﺎن 0/1 درﺻﺪ اﻟﯿﺎف ﭘﻠﯽﭘﺮوﭘﯿﻠﻦ و 22/5 درﺻﺪ ﻣﺘﺎﮐﺎﺋﻮﻟﻦ ﻧﺴﺒﺖ ﺑﻪ ﻧﻤﻮﻧﻪ ﻣﺮﺟﻊ رخ داد. ﻓﺮﻣﻮلﻫﺎی ﺗﺤﻠﯿﻠﯽ ﻣﻘﺎوﻣﺖ و ﺟﺬب آب در ﺑﺘﻦ ﻏﻠﺘﮑﯽ ﺑﻪ ﺻﻮرت ﺗﻮاﺑﻊ دو ﻣﺘﻐﯿﺮه از ﻣﺘﺎﮐﺎﺋﻮﻟﻦ و اﻟﯿﺎف ﭘﻠﯽﭘﺮوﭘﯿﻠﻦ ﺑﻪ ﺧﻮﺑﯽ ﺧﻮاص ﺑﺘﻦ ﻏﻠﺘﮑﯽ و درﺻﺪ ﺑﻬﯿﻨﻪ اﺳﺘﻔﺎده از ﺗﺮﮐﯿﺒﺎت ﻓﻮق را ﭘﯿﺶﺑﯿﻨﯽ ﻧﻤﻮد.

experimental and analytical investigation of metakaolin and polypropylene fiber addition on some properties of roller compacted concrete pavement

in this study, mechanical properties of roller compacted concrete pavement (rccp) containing metakaolin (mk) with or without polypropylene fibers (pp) are experimentally and analytically investigated. for this purpose, 16 different mixes were designed and tested in the laboratory. effect of using polypropylene fibers in 0, 0.05, 0.1 and 0.2 percent of cement volume with metakaolin powder in 0, 7.5, 15 and 22.5 percent of cement weight was investigated. compressive strength, tensile strength and water adsorption were evaluated. results showed that highest compressive strength occurs in combination of 0.1% of pp and 15% of mk that increases the compressive strength of 7 and 28 days respectively, by 51% and 25% compared to the reference sample. the tensile strength using the above combination increased by 42%, which is the highest increase in the tensile strength. by using 0.1% of pp and 22.5% of mk, maximum decrease in water adsorption (11%) was observed as compared to the reference sample. in this research, analytical formulas predicted properties of the rccp and estimated optimal combination of the pp and mk.