بهبود پارامترهای مکانیکی بتن حاصل از سیمان پوزولانی جهت استفاده در پروژه های آبیاری و زهکشی

اﯾﻦ ﻣﻘﺎﻟﻪ ﺑﻪ ﮐﻤﯽ ﺳﺎزی ﻋﺪم ﻗﻄﻌﯿﺖ ﻧﺎﺷﯽ از ﻣﺪل ﺳﺎزی ﺳﺎزه ﻫﺎی ﻓﻮﻻدی ﺗﻮﺳﻂ ﺗﯿﺮ ﺗﯿﻤﻮﺷﻨﮑﻮ ﻣﯽ ﭘﺮدازد. ﯾﮑﯽ از روش ﻫﺎی ﻣﺮﺳﻮم در ﺗﺤﻠﯿﻞ دﯾﻨﺎﻣﯿﮏ ﺳﺎزه ﻫﺎ، ﻣﺪل ﮐﺮدن ﺳﺎزه ﻫﺎی ﺳﺎﺧﺘﻤﺎﻧﯽ ﺗﻮﺳﻂ ﻣﺪل ﻫﺎی ﺗﯿﺮ ﭘﯿﻮﺳﺘﻪ اﺳﺖ. اﺳﺘﻔﺎده از ﺗﯿﺮ ﺗﯿﻤﻮﺷﻨﮑﻮ، ﺑﻪ ﻋﻨﻮان ﯾﮏ ﮐﻼس از ﻣﺪل ﻫﺎی ﺗﯿﺮ ﭘﯿﻮﺳﺘﻪ، ﺑﻪ ﺟﺎی ﯾﮏ ﻣﺪل اﺟﺰای ﻣﺤﺪود ﺑﻪ ﺗﺴﺮﯾﻊ ﻣﺤﺎﺳﺒﺎت ﻣﻨﺠﺮ ﻣﯽ ﺷﻮد. اﯾﻦ ﮐﺎﻫﺶ ﻣﺤﺎﺳﺒﺎت، اﻣﮑﺎن ﺷﻨﺎﺳﺎﯾﯽ اﺣﺘﻤﺎﻻﺗﯽ ﺑﺮﺧﻂ ﺳﺎزه ﻫﺎی ﺳﺎﺧﺘﻤﺎﻧﯽ و ﺗﺸﺨﯿﺺ ﺳﺮﯾﻊ ﺧﺮاﺑﯽ در آن ﻫﺎ را ﭘﺲ از ﯾﮏ روﯾﺪاد ﻟﺮزه ای ﻓﺮاﻫﻢ ﻣﯽ ﺳﺎزد. ﻻزﻣﻪ ﺷﻨﺎﺳﺎﯾﯽ ﺳﺎزه ﻫﺎ ﺑﻪ اﯾﻦ روش، ﮐﻤﯽ ﺳﺎزی ﻋﺪم ﻗﻄﻌﯿﺖ ﻧﺎﺷﯽ از ﺗﻘﺮﯾﺐ ﺳﺎزه ﺑﺎ ﯾﮏ ﺗﯿﺮ ﭘﯿﻮﺳﺘﻪ اﺳﺖ ﮐﻪ ﻫﺪف اﺻﻠﯽ اﯾﻦ ﭘﮋوﻫﺶ را ﺗﺸﮑﯿﻞ ﻣﯽ دﻫﺪ. ﺑﺪﯾﻦ ﻣﻨﻈﻮر ﺑﺎ ﺗﻮﺳﻌﻪ ﯾﮏ ﺳﯿﺴﺘﻢ ﺧﻮدﮐﺎر، ﺗﻌﺪاد 1000 ﻣﺪل اﺟﺰای ﻣﺤﺪود ﺳﺎزه ﺳﺎﺧﺘﻤﺎﻧﯽ ﻃﺮاﺣﯽ ﺷﺪه و ﺗﺤﺖ ﺗﺤﻠﯿﻞ ﻣﻘﺪار وﯾﮋه ﻗﺮار ﻣﯽ ﮔﯿﺮﻧﺪ ﺗﺎ ﺑﺴﺎﻣﺪ و ﺷﮑﻞ ﻣﻮدی ﻃﺒﯿﻌﯽ آن ﻫﺎ ﺗﻌﯿﯿﻦ ﺷﻮد. ﺑﺮای ﻫﺮ ﺳﺎزه، ﺗﯿﺮ ﺗﯿﻤﻮﺷﻨﮑﻮی ﻣﻌﺎدل آن ﺗﻌﯿﯿﻦ ﻣﯽ ﺷﻮد. ﺳﭙﺲ، ﺧﻄﺎی ﻧﺎﺷﯽ از ارﺿﺎ ﻧﺸﺪن ﻣﻌﺎدﻟﻪ ﻣﺸﺨﺼﻪ ﺗﯿﺮ ﺗﯿﻤﻮﺷﻨﮑﻮ ﺑﻪ ازای ﺑﺴﺎﻣﺪ و ﺷﮑﻞ ﻣﻮدی ﻧﺎﺷﯽ از ﻣﺪل دﻗﯿﻖ اﺟﺰای ﻣﺤﺪود ﻣﺤﺎﺳﺒﻪ ﻣﯽ ﺷﻮد. ﺑﺎ ﺗﺤﻠﯿﻞ آﻣﺎریِ اﯾﻦ ﺧﻄﺎﻫﺎ ﺑﺮای ﺳﯿﺴﺘﻢ ﻫﺎی ﻣﺨﺘﻠﻒ، ﻣﺸﺨﺼﺎت ﺗﻮزﯾﻊ اﺣﺘﻤﺎل ﺧﻄﺎ، از ﺟﻤﻠﻪ ﺷﮑﻞ ﺗﻮزﯾﻊ، ﻣﯿﺎﻧﮕﯿﻦ و اﻧﺤﺮاف ﻣﻌﯿﺎر آن ﺗﻌﯿﯿﻦ ﻣﯽ ﺷﻮد. ﻧﺘﺎﯾﺞ ﻧﺸﺎن ﻣﯽ دﻫﺪ ﮐﻪ ﻣﯿﺰان ﺧﻄﺎ ﺣﺴﺎﺳﯿﺖ اﻧﺪﮐﯽ ﺑﻪ ﻃﻮل، ﻋﺮض و ارﺗﻔﺎع ﺳﺎزه دارد، اﻣﺎ ﺑﻪ ﺳﯿﺴﺘﻢ ﺳﺎزﻫﺎی ﺑﺴﯿﺎر واﺑﺴﺘﻪ اﺳﺖ. ﺑﺮ اﺳﺎس اﯾﻦ ﻧﺘﺎﯾﺞ، اﻧﺤﺮاف ﻣﻌﯿﺎر ﺧﻄﺎ ﺑﺮای ﺳﺎزه ﻫﺎﯾﯽ ﺑﺎ ﺳﯿﺴﺘﻢ ﻗﺎب ﺧﻤﺸﯽ ﻓﻮﻻدی 3/5 ﺑﺮاﺑﺮ ﮐﻤﺘﺮ از ﺳﺎزه ﻫﺎﯾﯽ ﺑﺎ ﺳﯿﺴﺘﻢ ﻣﻬﺎرﺑﻨﺪی ﻓﻮﻻدی اﺳﺖ. ﺑﻨﺎﺑﺮاﯾﻦ، ﮐﻼس ﻣﺪل ﺗﯿﺮ ﺗﯿﻤﻮﺷﻨﮑﻮ ﺗﻘﺮﯾﺐ ﺑﻬﺘﺮی از ﺳﯿﺴﺘﻢ ﻫﺎی ﻗﺎب ﺧﻤﺸﯽ ﻓﻮﻻدی اراﺋﻪ ﻣﯽ ﮐﻨﺪ.

Improvement of mechanical parameters of concrete yielded from pozzolanic cement for irrigation and drainage projects

Among various active parts of construction industry, irrigation and drainage projects (such as dams, spillways and peripheral parts such as canals) are one of the biggest consumers of cement. Various empirical reports show that the concrete made of Ardabil’s pozzolanic cement does not meet the requirement for irrigation and drainage projects in case of mechanical characteristics which signifies the importance of further research in this area. The objective of this study is to investigate the suitability of replacing Ardabil’s pozzolanic cement with type 2 Soufian cement from the viewpoint of compression strenght at irrigation and drainage projecta. This study focuses on experimental methods by performing standard compression strength tests on base and improved speimens. The initial results showed that solely utilization of Ardabil’s pozzolanic cement in structural parts is not feasible and there should be some other approaches to reach this end. In this regard, 4 additive materials were used instead of cement including: stone powder, fined part of sand, silica fume and fly ash. The results indicated that utilization of fly ash increases the compressive strength of the cement in long term application; however, it causes a reduction in compressive strength in short term application. Furthermore, replacemet of silica fume in lower percentages causes a reduction in compression strength; however, higher percentage of silica fume replacement increases compression strength. The finer parts of the sand slightly decreased the compression strength and the replacement of stone powder yields to an increase in long term compression strength.