ﺑﺘﻦآرﻣﻪ ﺑﯿﻀﯽﺷﮑﻞ ﺳﺎﺧﺘﻪ ﺷﺪه از ﺑﺘﻦ- ﻫﺎیﻣﻘﺎﯾﺴﻪ ﻋﺪدی و آزﻣﺎﯾﺸﮕﺎﻫﯽ رﻓﺘﺎر ﺳﺘﻮن ﺗﺤﺖ ﺑﺎر ﻣﺤﻮری دورﭘﯿﭻ و ﻫﺎی ﻣﻌﻤﻮﻟﯽ و ﭘﺮﻣﻘﺎوﻣﺖ ﺑﺎ و ﺑﺪون ﻏﻼف

در اﯾﻦ ﺗﺤﻘﯿﻖ ﺑﻪ ﻣﻘﺎﯾﺴﻪ ﻧﺘﺎﯾﺞ ﻋﺪدی و آزﻣﺎﯾﺸﮕﺎﻫﯽ رﻓﺘﺎر ﺳﺘﻮنﻫﺎی ﺑﺘﻦآرﻣﻪ ﺑﺎ ﻣﻘﻄﻊ ﺑﯿﻀﯽ ﺳﺎﺧﺘﻪﺷﺪه از ﺑﺘﻦﻫﺎی ﻣﻌﻤﻮﻟﯽ و ﭘﺮﻣﻘﺎوﻣﺖ ﮐﻪ ﺗﻮﺳﻂ ﻏﻼف ﭘﻼﺳﺘﯿﮑﯽ ﺗﻘﻮﯾﺖﺷﺪه ﺑﺎ اﻟﯿﺎف ﺷﯿﺸﻪ1 و دورﭘﯿﭻ اﻟﯿﺎف ﭘﻠﯿﻤﺮی ﺗﻘﻮﯾﺘﯽ ﮐﺮﺑﻦ2، ﻣﺤﺼﻮر ﺷﺪﻧﺪ، ﭘﺮداﺧﺘﻪ ﺷﺪ. ﻣﻨﻈﻮر از رﻓﺘﺎر، ﻇﺮﻓﯿﺖ ﻓﺸﺎری و ﺷﮑﻞﭘﺬﯾﺮی ﺳﺘﻮنﻫﺎ اﺳﺖ. ﺗﺄﺛﯿﺮ ﻧﻮع ﺑﺘﻦ، ﻏﻼف، دورﭘﯿﭻ و ﺗﻌﺪاد ﻻﯾﻪﻫﺎی آن ﺑﺮرﺳﯽ ﺷﺪﻧﺪ. 12 ﺳﺘﻮن ﺑﻪ ﻗﻄﺮﻫﺎی 200 و120 و ارﺗﻔﺎع 600ﻣﯿﻠﯽﻣﺘﺮ ﺳﺎﺧﺘﻪ ﺷﺪﻧﺪ. ﺳﺘﻮنﻫﺎ ﺑﻪ دو ﮔﺮوه 6ﺗﺎﯾﯽ از ﺑﺘﻦﻫﺎی ﻣﻌﻤﻮﻟﯽ و ﭘﺮﻣﻘﺎوﻣﺖ، و ﻫﺮ ﮔﺮوه ﻧﯿﺰ ﺑﻪ دو ﺑﺨﺶ 3ﺗﺎﯾﯽ ﺗﻘﺴﯿﻢ ﺷﺪﻧﺪ؛ ﺑﺨﺶ اول دارای ﻏﻼف و ﺑﺨﺶ دوم ﻓﺎﻗﺪ ﻏﻼف ﺑﻮدﻧﺪ. از ﻫﺮ ﺑﺨﺶ ﯾﮏ ﺳﺘﻮن ﻓﺎﻗﺪ دورﭘﯿﭻ، ﯾﮏ ﺳﺘﻮن ﯾﮏ ﻻﯾﻪ و ﺳﺘﻮن دﯾﮕﺮ دو ﻻﯾﻪ داﺷﺘﻨﺪ. ﻣﺪلﺳﺎزی ﻋﺪدی ﺑﺎ ﻧﺮماﻓﺰار آﺑﺎﮐﻮس3 اﻧﺠﺎم ﮔﺮدﯾﺪ و ﻧﺘﺎﯾﺞ ﺣﺎﺻﻠﻪ ﺑﺎ ﻧﺘﺎﯾﺞ آزﻣﺎﯾﺸﮕﺎﻫﯽ ﻣﻘﺎﯾﺴﻪ ﺷﺪﻧﺪ ﮐﻪ ﺗﻄﺎﺑﻖ ﺧﻮﺑﯽ ﺑﯿﻦ آنﻫﺎ ﺑﻪدﺳﺖ آﻣﺪ. ﻧﺘﺎﯾﺞ ﺗﺤﻘﯿﻖ ﻧﺸﺎن داد ﮐﻪ دورﭘﯿﭻ و ﻏﻼف ﺑﺎﻋﺚ ﺑﻬﺒﻮد رﻓﺘﺎر ﺳﺘﻮنﻫﺎ ﮔﺮدﯾﺪﻧﺪ. اﻓﺰودن ﯾﮏ ﻻﯾﻪ و دو ﻻﯾﻪ دورﭘﯿﭻ ﺑﻪ ﻃﻮر ﻣﯿﺎﻧﮕﯿﻦ در روش آزﻣﺎﯾﺸﮕﺎﻫﯽ ﺳﺒﺐ اﻓﺰاﯾﺶ %19/7 و %28/7 در ﻇﺮﻓﯿﺖ ﻓﺸﺎری در ﮔﺮوه اول و %11و %28/7 در ﮔﺮوه دوم و در روش ﻋﺪدی ﺳﺒﺐ اﻓﺰاﯾﺶ %19/9 و %36/6 در ﻇﺮﻓﯿﺖ ﻓﺸﺎری در ﮔﺮوه اول و % 16/8و %30/9 در ﮔﺮوه دوم ﮔﺮدﯾﺪ؛ ﮐﺎرﺑﺮد ﻏﻼف ﻣﯿﺎﻧﮕﯿﻦ اﻓﺰاﯾﺶ ﻇﺮﻓﯿﺖ ﺳﺘﻮنﻫﺎ در روش آزﻣﺎﯾﺸﮕﺎﻫﯽ در ﮔﺮوه اول ﺑﻪ ﻣﯿﺰان 4/15 ﺑﺮاﺑﺮ و در ﮔﺮوه دوم 3/51 ﺑﺮاﺑﺮ و در روش ﻋﺪدی در ﮔﺮوه اول ﺑﻪ ﻣﯿﺰان 4/26 ﺑﺮاﺑﺮ و در ﮔﺮوه دوم 3/25 ﺑﺮاﺑﺮ را ﻧﺘﯿﺠﻪ داد. ﻫﺮﭼﻨﺪ ﮐﻪ دورﭘﯿﭻ و ﻏﻼف ﻫﺮ دو ﻣﺤﺼﻮرﯾﺖ اﯾﺠﺎد ﻣﯽﮐﻨﻨﺪ، اﻣﺎ ﻣﻘﺎﯾﺴﻪ اﺛﺮ ﻣﺤﺼﻮرﯾﺖ ﻏﻼف ﺑﺎ دورﭘﯿﭻ ﻧﺸﺎن داد ﮐﻪ ﻏﻼف ﺑﻪ ﺧﺎﻃﺮ ﻣﺤﺼﻮرﯾﺖ ﺑﯿﺶﺗﺮ، ﺗﺎﺛﯿﺮ ﺑﺴﯿﺎر زﯾﺎدﺗﺮی ﺑﺮ ﺑﻬﺒﻮد رﻓﺘﺎر ﺳﺘﻮنﻫﺎ ﺑﻪوﯾﮋه ﺳﺘﻮنﻫﺎی ﺳﺎﺧﺘﻪ ﺷﺪه از ﺑﺘﻦ ﻣﻌﻤﻮﻟﯽ دارد.

experimental and numerical comparison of the behavior of elliptic rcc’s made of nc and hsc, with and without casing and wrapping, under axial load

in this study, the numerical and experimental results of the behaviour of rcc’s with an elliptic cross- section made of nc and hsc enclosed by a grp casing and a cfrp wrapping were compared. behaviour refers to the compressive capacity and ductility of columns. the effect of concrete type, casing, wrapping and layers number, were investigated. 12 columns with 200*120 diameter and 600 mm height were made. the columns were divided into two groups from nc and hsc, and each group was divided into two part of three; the first part had a casing and the second without casing. each part had a column without wrapping, 2nd with one layer, and 3rd column with two layers. numerical modelling was performed with abaqus software and the results were compared with experimental results, which were well matched. the results showed that the wrapping and casing improved the behaviour of the columns. addition of one layer and two layers of wrapping on average in the experimental method causes an increase of 19.7% and 28.7% in the cc in the 1st group and 11% and 28.7% in the 2nd group and in the numerical method causes an increase of 19.9% and 36.6% in cc in the 1st group and 16.8% and 30.9% in the 2nd group. averagely, the use of casing increased the capacity in the experimental method by 4.15 times in the 1st group and 3.51 times in the 2nd group; in the numerical method; this increase in the capacity in the 1st group was 4.26 times and in the 2nd group was 3.25 times. although the casing and the wrapping both create confinement, comparison showed that the casing, due to its greater confinement, has a much greater effect on improving the behaviour of columns, especially columns made of nc.