Experimental Investigation of the Piezoresistive Properties of Cement Composites with Hybrid Carbon Fibers and Nanotubes

Abstract

Cement-based sensors with hybrid conductive fillers using both carbon fibers (CFs) and multi-walled carbon nanotubes (MWCNTs) were experimentally investigated in this study. The self-sensing capacities of cement-based composites with only CFs or MWCNTs were found based on preliminary tests. The results showed that the percolation thresholds of CFs and MWCNTs were 0.5–1.0 vol.% and 1.0 vol.%, respectively. Based on these results, the feasibility of self-sensing composites with four different amounts of CFs and MWCNTs was considered under cyclic compression loads. When the amount of incorporated CFs increased and the amount of incorporated MWCNTs decreased, the self-sensing capacity of the composites was reduced. It was concluded that cement-based composites containing both 0.1 vol.% CFs and 0.5 vol.% MWCNTs could be an alternative to cement-based composites with 1.0 vol.% MWCNTs in order to achieve equivalent self-sensing performance at half the price. The gauge factor (GF) for that composite was 160.3 with an R-square of 0.9274 in loading stages I and II, which was similar to the GF of 166.6 for the composite with 1.0 vol.% MWCNTs.

Self-sensing Properties of Concrete with Electric Arc Furnace Slag and Steel Fiber

“…전도성재료를 혼입한 시멘트기반 복합재료의 자기센싱 특성을 평가하기 위하여 다음과 같은 저항변화율(Fractional change in resistivity, FCR)이 사용되고 있다 (Lee et al, 2017;Yoo, You, Youn, et al, 2018).…”

“…여기서   와   는 각각 시작점에서의 저항 그리고 하중이 변화함에 따라 측정된 저항을 의미하고,   과   는 시작점에 서의 비저항 그리고 하중변화에 따른 비저항을 나타낸다. 하중이 가해지는 과정에서 발생하는 부재의 길이 변화가 무시할 만큼 작은 경우 저항변화율은 비저항 변화율과 같다 고 볼 수 있으며, 본 연구에서는 이 저항변화율을 적용하였다 (Yoo, You, Youn, et al, 2018 Yoo, You, Youn, et al, 2018 (Lee et al, 2017;Yoo, You, Youn, et al, 2018…”

“…많은 연구자들은 전도성능이 뛰어난 탄소나노튜브(Carbon nanotube), 탄소섬유(Carbon fiber)를 시멘트기반 복합체 에 혼입하여 자기센싱 성능을 평가하였다. 이 밖에도 금속 분말, 카본블랙(Carbon black), 강섬유(Steel fiber) 등 전도 성 재료를 시멘트기반 복합체에 혼입하여 자기센싱에 관한 연구들도 수행되어 왔다 (Lee et al, 2017, Ackermann, 2018 (Wang et al, 2013;Hu et al, 2008). (Li et al, 2014).…”

Piezoresistive Chopped Carbon Fiber Rubber Silicone Sensors for Shedding Frequency Detection in Alternating Vortex Streets

“…While the composites can also achieve extreme gauge factors [16], [20] cost of materials and need of careful handling might make them less desirable for implementation in low budget and rapid prototyping projects. Combating this, it has been shown that introducing chopped carbon fibers (CCF) along with CNT in sensor materials might yield similar sensor properties while greatly reducing production cost [21]. Similar to CNT, CB, and graphene, carbon fibers show piezoresistive properties that can be used to create sensors on their own [22]- [24].…”

Stability of GO Modified by Different Dispersants in Cement Paste and Its Related Mechanism

“…Nano-materials have shown to improve the micro-structure and comprehensive performance of cement-based composites [ 3 , 4 , 5 , 6 ]. Moreover, several studies on self-sensing cement composites which uses nanocomposites have also been reported [ 7 , 8 , 9 ]. Thus, nano-modified cement-based materials are the main technical ways for developing ultra-high-performance concrete (UHPC).…”