PSI - Issue 28

Angeliki-Eirini Dimou et al. / Procedia Structural Integrity 28 (2020) 1694–1701 A.-E. Dimou et al. / Structural Integrity Procedia 00 (2019) 000–000

1700

7

1.0

0.8

0.74 MOhm

0.61 MOhm 0.65 MOhm

0.6

0.9

0.4

0.2

blank paste

Blank paste

rGO

0.8

0.0

reinforced paste

MWCNTsCOOH

reinforced paste

Electrical Resistance (MOhm)

MWCNTsCOOH reinforced paste

0.7

rGO reinforced paste

Electrical Resistance (MOhm)

0.6

0

5

10

15

20

25

30

Time (minutes)

Fig. 6. Electrical resistance of the pastes at 28 d of age.

4. Conclusions The mechanical and electrical properties of CBN-reinforced NHL pastes for restoration applications were investigated. The results showed that the addition of MWCNTsCOOH at 0.15 wt % lead to a 56 % increase of flexural strength, while the compressive strength did not display any significant changes. Regarding the rGO reinforcement, the inverse phenomenon was observed. The compressive strength of the reinforced paste was increased about 20 % while the flexural strength remained almost constant when compared to the respective property of the original matrix. The electrical resistance drops in both cases by approximate 15 %. The experimental results indicate that CBNs can be successfully incorporated in hydraulic binders for the development of nano-composite mortars to be used in the restoration interventions of traditional buildings and Cultural Heritage buildings. Acknowledgements This research has been co‐financed by the European Regional Development Fund of the European Union and Greek national funds through the Operational Program Competitiveness, Entrepreneurship and Innovation, under the call RESEARCH – CREATE – INNOVATE (project code: T1EDK-03069, MIS 5031866, project name: Self-healing and self-sensing nano-composite conservation mortars – acronym: AKEISTHAI). The authors would like to thank Abolin Co. for kindly providing the binder materials (natural hydraulic lime and the metakaolin). References Alves e Silva, R., de Castro Guetti, P., da Luz, M.S., Rouxinol , F., Gelamo, R.V., 2017. Enhanced properties of cement mortars with multilayer graphene nanoparticles. Construction and Building Materials 149, 378-385. Arrechea, S., Guerrero-Gutiérrez, E.M.A., Velásquez, L., Cardona, J., Posadas, R., Callejas, K., Torres, S., Díaz, R., Barrientos, C., García, E., 2020. Effect of additions of multiwall carbon nanotubes (MWCNT,MWCNT-COOH and MWCNT-Thiazol) in mechanical compression properties of a cement-based material. Materialia 11, 100739. Banthia, N., Djeridane, S., Pigeon, M., 1992. Electrical Resistivity of Carbon and Steel Micro-Fiber. Cement and Concrete Research 22, 804-811. Danoglidis, P.A., Konsta-Gdoutos, M.S., Gdoutos, E.E., Shah, S.P., 2016. Strength, energy absorption capability and self-sensing properties of multi functional carbon nanotube reinforced mortars. Construction and Building Materials 120, 265-274. Dimou, A.E., Sakellariou, I., Maistros, G., Alexopoulos N.D., 2020. Study of reduced graphene oxide dispersions via electrical impedance spectroscopy. Manuscript submitted for publication. Du, H., Pang, S.D., 2015. Enhancement of barrier properties of cement mortar with graphene nanoplatelet. Cement and Concrete Research 76, 10-19. Fang, S., Zhang, K., Zhang, H., Zhang, B., 2015. A study of traditional blood lime mortar for restoration of ancient buildings. Cement and Concrete Research 76, 232-241. Faria, P., Duarte, P., Barbosa, D., Ferreira, I., 2017. New composite of natural hydraulic lime mortar with graphene oxide. Construction and Building Materials 156, 1150-1157.