Carbon Nanotubes and their Application in the Construction Industry

Abstract

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Nanoscale Modification of Cementitious Materials

“…Few attempts have been made to add CNTs in cementitious matrices at an amount ranging from 0.5 to 2.0% by weight of cement. Previous studies have focused on the dispersion of CNTs in liquids by pre-treatment of the nanotube's surface via chemical modification [2][3][4][5][6][7][8]. Preliminary research has shown that small amounts of CNTs can be effectively dispersed in cementitious matrix [13].…”

“…However, cement matrix exhibits flaws which are at the nanoscale. The development of new nanosized fibers, such as carbon nanotubes (CNTs), has opened a new field for nanosized reinforcement within concrete [2][3][4][5][6][7][8]. The remarkable mechanical properties of CNTs [9][10] suggest that are ideal candidates for high performance cementitious composites.…”

Yüksek Performanslı Harç Üretiminde Optimum Nano Malzeme Oranlarının Belirlenmesi

“…İnce tanecikli malzemeler kullanılan betonun mukavemeti de normal betondan daha çok olacaktır [17,18]. Beton ile yapılan son çalışmalarda kullanılan nano alümine, nano kalsit ve nano silikanın normal betona göre beton mukavemetini arttırdığı gözlemlenmiştir [19]. Nazari ve Riahi'nin [20,21] akademik yayınlarında ağırlık olarak çimento yerine %4' e varan miktarlarda nano-silika kullanılması sonucunda beton numunelerinin basınç dayanımlarında belli oranda artış meydana gelmiştir.…”

Performance of carbon nanofiber-cement composites subjected to accelerated decalcification

“…It is interesting to note that the PC-CNF composite experienced a decrease in porosity as the exposure duration increased (from 6.1% prior to exposure to 5.2% after 125 days of exposure), while the PC paste experienced the opposite trend (increase in porosity from 5.1% to 6.6%). The greater local porosity initially caused by the CNF agglomerates 02005-p. 4 decreased during decalcification due to a filling effect of the CNF agglomerates as a result of the precipitation of secondary hydration within the agglomerates. …”

“…Lately, with the recent advances in nanotechnology, the use of carbon nanofibers (CNFs) in cement composites has received increasing attention due to the promising potential for the development of superior structural and multifunctional materials [2]. CNFs possess a number of unique properties, such as high specific strength, chemical resistance, and electrical and thermal conductivity, making them excellent candidates for nanoscale reinforcement in cement composites [3,4]. While most studies to date have been conducted to examine the direct structural, mechanical, and electrical properties provided by the CNFs [5][6][7], the long-term chemical and structural stability of these materials in response to severe conditions such as decalcifying environments and the potential impact of the CNF dispersion on the chemo-mechanical behavior of CNF-cement composites has received little attention.…”