USE OF 2-D NANO-PARTICLE TO ENHANCE THE CONCRETE RESISTANCE TO CHLORIDE INGRESS
Author(s): Du, H., Gao, H. J. and Pang, S. D.
Paper category: Conference
Book title: XIII International Conference on Durability of Building Materials and Components - XIII DBMC
Editor(s): Marco Quattrone, Vanderley M. John
Print ISBN: none
Publication year: 2015
Total Pages: 8
Abstract: Experiments are carried out in this study to improve the durability of cement composites using 2-D nano-particles, namely graphene nanoplatelet (GNP). GNP was added into concrete at content of 0, 0.5%, 1.0%, 1.5, 2.0 and 2.5% by weight of cement. Compared with the commonly used 0-D and 1-D nano-particle (represented by nano-silica and carbon nanotube, respectively), this 2-D material has the advantage of barrier effect which can increase the tortuosity for the harmful agents to pass through the composites, leading to better durability performance. Chloride migration coefficient and diffusion coefficient were determined for each concrete mix, corresponding to accelerated and non-accelerated chloride penetration test, respectively. Both test results reveal that the resistance to chloride ion ingress decreases with GNP content, with the greatest resistance using 1.5% GNP where a reduction of 37% and 80% in the chloride migration coefficient and diffusion coefficient respectively were measured. Pore size distribution was probed using mercury intrusion porosimetry (MIP) and the result showed that 1.5% GNP addition can produce concrete with the lowest fraction of macropores and smallest average pore size. This supports the observations made for the chloride ingress where the concrete mix with 1.5% GNP showed the highest durability performance. However, clustering of GNP at higher contents compromises its improvement on the concrete durability due to agglomeration, resulting in formation of weak pockets and porous zones. This adverse influence might be overcome by better exfoliation and processing methods that are currently being explored.
Online publication: 2015
Publication Type: full_text
Public price (Euros): 0.00