Issue 41

X. Wu et alii, Frattura ed Integrità Strutturale, 41 (2017) 388-395; DOI: 10.3221/IGF-ESIS.41.50 394 moreover carbon tubes would consume part of energy in the form of energy consumption in pullout, which could help improving breaking energy and overcoming fragility. Figure 8 : The observation results of carbon nano-tubes under a SEM. C ONCLUSIONS he mixing of a certain amount of carbon nano-tubes can enhance the mechanical properties of cement-based composite materials. After analyzing the condition in the 7th, 14th and 28th d, it was found that the mixing of 0.10 wt% carbon nano-tubes had the best effect in improving the mechanical properties of cement-based composite materials; the bending and compressive strength improved for 12% approximately. In the analysis using SEM, it was found that, carbon nano-tubes produced bridging and pullout effects in the cement-based materials and absorbed more damage energy to ensure the integrity of composite materials and protect the cement-based materials from external damages. A CKNOWLEDGEMENT eneral program of university natural science research of education department of Jiangsu, NO: (16KJB560011). R EFERENCES [1] Lo, T.Y., Cui, H.Z., Li, Z.G. Influence of aggregate pre-wetting and fly ash on mechanical properties of lightweight concrete. Waste Management, 24(4) (2004) 333-338. [2] Hunashyal, A.M., Sundeep, G.V., Quadri, S.S., et al. Experimental investigations to study the effect of carbon nanotubes reinforced in cement-based matrix composite beams. Proceedings of the Institution of Mechanical Engineers, Part N: Journal of Nanoengineering and Nanosystems, 225(1) (2011)17-22. [3] Konsta-Gdoutos, M.S., Metaxa, Z.S., Shah, X.P. Multi-scale mechanical and fractural characteristics and early-age strain capacity of high performance carbon nanotubes/cement nanocomposites. Cemnet and Concrete Composites, 32(2) (2010) 110-115. [4] Chaipanich, A., Nochaiya, T., Wongkeo, W., Torkittikul, P. Compressive strength and microstructure of carbon nanotubes-fly ash cement composites. Materials Science and Engineering: A, 527(4-5) (2010) 1063-1067. [5] Lahiri, I., Seelaboyina, R., Hwang, J.Y., et al. Enhanced field emission from multi-walled carbon nanotubes grown on pure copper substrate. Carbon, 48 (2010) 1531-1538. [6] Yang, W., Thordarson, P., Gooding, J.J., et al. Carbon nanotubes for biological and biomedical applications. Nanotechnology, 41 (2007) 412001-1-8. [7] Yan, J., Liu, J., Fan, Z., et al. High-performance supercapacitor electrodes based on highly corrugated grapheme sheets. Carbon, 50 (2012) 2179-2188. T G