Bond behavior of carbon-fiber yarn embedded in cement mortar

Abstract

This paper deals with the infl uence of admixtures -silica fume, superplasticizer and air entraining agent -on the improvement of the bond strength between bundled carbon fi laments and cement mortars. Pull-out tests were carried out to examine the bond between carbon-fi ber yarn and various cement matrices. An overall microstructural analysis was conducted and correlated with pull-out data. Experimental results showed that all the applied admixtures contributed to improved bonding. The air entraining agent was found to be the most effective in improving the bond strength of the studied carbon-fi ber reinforced cement mortar. Air bubbles formed inside the mortar mix as a result of added air entraining agent and the ones formed in the vicinity of the outer fi laments of the yarn may provide a mechanical barrier at the interface, leading to a signifi cant increase in interface friction.

Performance and Cost-Effectiveness of Short Pitch-Based Carbon Fiber Reinforced Mortar Composite

“…Moreover, silica fume contributes to decreasing the capillary porosity of cement composites [ 68 , 69 ] through its micro-filling ability and pozzolanic activity. In addition, it improves the interfaces of sand particles and carbon fibers [ 70 , 71 ] due to pore filling. However, all these improvements greatly depend on the workability of CFRM.…”

Comparison of Various Techniques for Flexural Strengthening of Thin Concrete Members Using Continuous Carbon Fibers

“…This observation indicates presumably tougher behavior of cement composites made with an aerated matrix. It was concluded in previous work of Ivanič et al [8], that air bubbles formed inside the mortar mix as a result of added air entraining agent, can slow down, or even prevent a cracking process. This can lead to reduced brittleness and increased toughness of the composite, respectively.…”