بررسی تاثیرات مصالح کامپوزیتی پایه سیمانی بر مقاومت سیستم قاب خمشی بتنی تحت شرایط خرابی پیشرونده

ﻋﻤﻠﮑﺮد اﺗﺼﺎﻻت ﺗﯿﺮ – ﺳﺘﻮن ﻧﻘﺸﯽ ﮐﻠﯿﺪی در ﺣﻔﻆ ﭘﺎﯾﺪراری ﺳﺎزهﻫﺎی ﺑﺘﻦ ﻣﺴﻠﺢ ﺗﺤﺖ ﺷﺮاﯾﻂ ﺧﺮاﺑﯽ ﭘﯿﺸﺮوﻧﺪه داﺷﺘﻪ و ﻃﺮاﺣﯽ ﻣﻨﺎﺳﺐ اﯾﻦ ﻧﺎﺣﯿﻪ از اﻧﻬﺪام ﻧﺎﮔﻬﺎﻧﯽ ﺳﺎزه ﺟﻠﻮﮔﯿﺮی ﻣﯽﻧﻤﺎﯾﺪ. رﻓﺘﺎر ﻣﻨﺤﺼﺮ ﺑﻪ ﻓﺮد ﻣﺼﺎﻟﺢ ﮐﺎﻣﭙﻮزﯾﺘﯽ ﭘﺎﯾﻪ ﺳﯿﻤﺎﻧﯽ اﻟﯿﺎﻓﯽ ﺑﺎﻋﺚ ﮔﺮدﯾﺪه اﺳﺖ اﯾﺪه اﺳﺘﻔﺎده از اﯾﻦ ﻣﺼﺎﻟﺢ ﺑﻪ ﻋﻨﻮان ﺟﺎﯾﮕﺰﯾﻨﯽ ﺑﺮای ﺑﺘﻦ ﻣﻌﻤﻮﻟﯽ در ﺳﺎﻟﻬﺎی اﺧﯿﺮ ﻣﻮﺿﻮع ﺗﺤﻘﯿﻖ ﺑﺴﯿﺎری از ﻣﻬﻨﺪﺳﯿﻦ ﺳﺎزه ﺑﺎﺷﺪ. در اﯾﻦ ﻣﻄﺎﻟﻌﻪ ﺑﻪ ارزﯾﺎﺑﯽ ﺗﺎﺛﯿﺮات ﺑﮑﺎرﮔﯿﺮی ﻣﺼﺎﻟﺢ ﮐﺎﻣﭙﻮزﯾﺘﯽ ﭘﺎﯾﻪ ﺳﯿﻤﺎﻧﯽ اﻟﯿﺎﻓﯽ در ﻧﻮاﺣﯽ اﺗﺼﺎﻻت ﺗﯿﺮ – ﺳﺘﻮن و اﺛﺮات اﺳﺘﻔﺎده از آن ﺑﺮ ﻣﻘﺎوﻣﺖ ﺳﺎزهﻫﺎی ﺑﺘﻨﯽ در ﺑﺮاﺑﺮ ﺧﺮاﺑﯽ ﭘﯿﺸﺮوﻧﺪه ﭘﺮداﺧﺘﻪ ﺷﺪه اﺳﺖ. ﺑﻪ اﯾﻦ ﻣﻨﻈﻮر ﺑﻌﺪ از ﺻﺤﺖ ﺳﻨﺠﯽ ﺷﺒﯿﻪ ﺳﺎزیﻫﺎ ﺑﺎ ﻧﺘﺎﯾﺞ آزﻣﺎﯾﺸﮕﺎﻫﯽ ﺑﺎ اﺳﺘﻔﺎده از ﻧﺮم اﻓﺰار opensees ﻋﻤﻠﮑﺮد ﻣﻘﺎوﻣﺘﯽ دو ﺳﺎزه 10 ﻃﺒﻘﻪ ﺑﺘﻨﯽ ﺗﺤﺖ ﺷﺮاﯾﻂ ﺧﺮاﺑﯽ ﭘﯿﺸﺮوﻧﺪه ﻣﻮرد ﻣﻄﺎﻟﻌﻪ ﻗﺮار ﮔﺮﻓﺘﻪ اﺳﺖ. ﻣﻘﺎوﻣﺖ ﻧﻤﻮﻧﻪﻫﺎی ﻣﻮرد ﻣﻄﺎﻟﻌﻪ ﺑﺎ اﺳﺘﻔﺎده از ﺷﺎﺧﺺ ﻣﻘﺎوﻣﺖ ﭘﯿﺸﻨﻬﺎدی ﺗﻮﺳﻂ ﻓﺴﺘﯽ و ﻫﻤﮑﺎران ﺳﻨﺠﯿﺪه ﺷﺪه اﺳﺖ ﮐﻪ ﯾﮑﯽ از ﺟﺎﻣﻊ ﺗﺮﯾﻦ و ﻗﺎﺑﻞ اﻋﺘﻤﺎد ﺗﺮﯾﻦ روﺷﻬﺎی ﻣﻮﺟﻮد ﺟﻬﺖ ارزﯾﺎﺑﯽ ﻣﻘﺎوﻣﺘﯽ ﺳﺎزهﻫﺎی ﺑﺘﻨﯽ ﻣﯽﺑﺎﺷﺪ. ﺷﺎﺧﺺ ﻣﻘﺎوﻣﺖ ﻓﺴﺘﯽ ﺗﻠﻔﯿﻘﯽ از ﺗﺤﻠﯿﻞﻫﺎی دﯾﻨﺎﻣﯿﮑﯽ ﻏﯿﺮﺧﻄﯽ و اﺳﺘﺎﺗﯿﮑﯽ ﻏﯿﺮﺧﻄﯽ ﻣﯽﺑﺎﺷﺪ ﮐﻪ ﻣﻘﺎوﻣﺖ ﺳﺎزه در ﺑﺮاﺑﺮ ﺧﺮاﺑﯽ ﭘﯿﺸﺮوﻧﺪه را ﻣﻮرد ارزﯾﺎﺑﯽ ﻗﺮار ﻣﯽدﻫﺪ. ﻧﺘﺎﯾﺞ ﺣﺎﺻﻞ از ﺗﺤﻠﯿﻞ ﻧﻤﻮﻧﻪﻫﺎ ﻧﺸﺎن ﻣﯽدﻫﺪ اﺳﺘﻔﺎده از ﻣﺼﺎﻟﺢ ﮐﺎﻣﭙﻮزﯾﺘﯽ ﭘﺎﯾﻪ ﺳﯿﻤﺎﻧﯽ اﻟﯿﺎﻓﯽ در ﻧﻮاﺣﯽ اﺗﺼﺎل ﺗﯿﺮ- ﺳﺘﻮن ﺑﺎ اﻓﺰاﯾﺶ ﻣﻘﺎوﻣﺖ و ﺷﮑﻞ ﭘﺬﯾﺮی ﺳﺎزه ﻣﯽﺗﻮاﻧﺪ ﻣﻘﺎوﻣﺖ ﺳﺎزه در ﺑﺮاﺑﺮ ﺧﺮاﺑﯽ ﭘﯿﺸﺮوﻧﺪه را ﺑﻬﺒﻮد ﺑﺨﺸﺪ. ﻫﻤﭽﻨﯿﻦ ﻣﺸﺎﻫﺪه ﮔﺮدﯾﺪ اﺳﺘﻔﺎده از ﻣﺼﺎﻟﺢ ﮐﺎﻣﭙﻮزﯾﺘﯽ ﭘﺎﯾﻪ ﺳﯿﻤﺎﻧﯽ اﻟﯿﺎﻓﯽ در ﻧﻮاﺣﯽ اﺗﺼﺎﻻت ﺗﯿﺮ- ﺳﺘﻮن ﺷﺎﺧﺺﻫﺎی ﻣﻘﺎوﻣﺖ دﯾﻨﺎﻣﯿﮑﯽ ﻏﯿﺮﺧﻄﯽ و اﺳﺘﺎﺗﯿﮑﯽ ﻏﯿﺮﺧﻄﯽ ﺳﺎزه را ﺑﻪ ﺗﺮﺗﯿﺐ 25/22 و 58/32 % ﻧﺴﺒﺖ ﺑﻪ ﺳﺎزه ﺑﺎ اﺗﺼﺎﻻت ﺑﺘﻦ ﻣﻌﻤﻮﻟﯽ اﻓﺰاﯾﺶ ﻣﯽدﻫﺪ.

investigation the effects of hpfrcc materials on the robustness of rc frames subjected to progressive collapse

reinforced concrete (rc) frames cover a large part of our country’s structures. neglect progressive collapse in this type of structures can lead to significant human and financial costs. most of the regulations related to rc frames have comprehensive measures for resistance to seismic forces but there are only a few general solutions to increase the robustness to progressive collapse have been provided. in this study the effects of using high performance fiber reinforced cementitious composite materials (hpfrcc) in the beam-column joints and the effects of its use on the robustness of rc frames against progressive collapse have been evaluated. for this purpose, after verifying the simulations with experimental tests using opensees software the robustness of two 10-story rc frames under progressive collapse has been evaluated. the performance of the samples was measured using the robustness index proposed by fascetti et al. the fascetti robustness index is a combination of nonlinear dynamic and nonlinear static analyzes that evaluate the structural robustness to progressive collapse under multi columns removing scenario. the results of the sample analysis show the use of hpfrccs materials in the joints beam-column can dramatically improve the robustness of concrete frames against progressive collapse by increasing the stiffness and ductility of the beam-column joints.