3RD INTERNATIONAL CONGRESS ON TECHNOLOGY - ENGINEERING & SCIENCE - Kuala Lumpur - Malaysia (2017-02-09)

Effect Of Cycles Of Freezing And Thawing On Nanotube Mixed Concrete Behavior
As concrete structures being threatened by aggressive conditions, the maintenance and rehabilitation of these structures have been widely studied by researchers. One of the most threat to concrete structures is successive cycles of freezing and thawing. The main object of this study is to investigate the effects of multi-walled carbon nanotubes MWCNT on the durability of concrete structures against the successive cycles of freezing and thawing. In this study, an equal ratio of water-cement has been considered and for preparing concrete mix design; 0.045, 0.15 and 0.2 of concrete weight have been replaced by MWCNT with the length of 20-30 Nm respectively. Then for designing the cycles of freezing and thawing, the concrete samples has been made for 30 and 150 cycles based on ASTM C66B. The results showed that, at the cycles of 30, control samples have the most compressive strength while the concrete mix design has respectively 15.4, 8.2 and 3.54 percent of compressive strength lower than control samples. At the cycle of 150 more damaged has been appeared and control samples have the less compressive strength. the concrete mix design has respectively 9.6, 26.96 and 31.85 percent of compressive strength higher than control samples and finally, it has resulted that in the cycles of freezing and thawing with MWCNT the appeared damages are less and compressive strength is been shown better performance in comparison with control samples as shown in Figure 1.
Keywords: Nano-technology, multi-walled carbon nanotubes, Durability of against frost, compressive strength.

Mohammad Noraeezadeh, S. Mohammad Mirhosseini Hezave, Ali Hassani Joshaghani