Influence of Cementitious Capillary Crystalline Waterproofing Material on the Water Impermeability and Microstructure of Concrete

Abstract:

The main objective of this study is to investigate the effect of cementitious capillary crystalline waterproofing (CCCW) material on the water impermeability and microstructure of concrete. The water impermeability of concrete covered with or without CCCW material was tested according to the Chinese standard GB 18445-2012. The results indicate that concretes coated with CCCW material showed much higher water impermeability than blank ones, and the ratio of water impermeability pressure between them reached 275. The samples obtained in various depths of hardened cement paste specimens with or without CCCW coating were analyzed through scanning electron microscopy (SEM) and thermogravimetry-differential scanning calorimetry (TG-DSC), to study the differences in microstructure and hydration products. The results present that after a 28-day standard curing, there were lots of ettringite crystals and CaCO₃ formed in the paste in 1 cm from the coating, but the action depth of the CCCW coating could not reach 3 cm. The ettringite and CaCO₃ is precipitated in the pore structure of cement matrix and filling the voids, which leads to the significant enhancement in water impermeability.

• Periodical: Materials Science Forum (Volume 953)
• Pages: 209-214
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.953.209
• Online since: May 2019
• Authors: Yi Teng Zhang*, Lian Zuo, Jin Chao Yang, Wei Xia Zhao, Xiang Xiong Zeng
• Keywords: CaCO₃, Cementitious Capillary Crystalline Waterproofing Material (CCCW), Ettringite, Penetration Depth, Water Impermeability

References

[1] GB 18445-2012, Cementitious capillary crystalline waterproofing materials.

[2] Y. Yu, T. Sun, Polymer-modified cement waterproofing coating and cementitious capillary crystalline waterproofing materials: mechanism and applications, Key Eng. Mater. 726 (2017) 527-531.

DOI: 10.4028/www.scientific.net/kem.726.527

[3] L. Ferrara, V. Krelani, M. Carsana, A 'fracture testing', based approach to assess crack healing of concrete with and without crystalline admixtures, Constr. Build. Mater. 68 (2014) 535–551.

DOI: 10.1016/j.conbuildmat.2014.07.008

[4] D.T. Niu, J.B. Wang, Y. Wang, Effect of hydration aging and water binder ratio on microstructure and mechanical properties of sprayed concrete, J. Wuhan Univ. Technol. –Mater. Sci. Ed. 30 (2015) 745-751.

DOI: 10.1007/s11595-015-1222-6

[5] L.B. Li, C.C. Gong, S.D. Wang, L.C. Lu, X. Cheng, Effect of natural zeolite on performance of sulfoaluminate cement-based planting cementitious material, J. Wuhan Univ. Technol. –Mater. Sci. Ed. 32 (2017) 386-390.

DOI: 10.1007/s11595-017-1638-2

[6] S.Y. Duan, H.Q. Liao, F.Q. Cheng, H.P Song, H.Q. Yang, Investigation into the synergistic effects in hydrated gelling systems containing fly ash, desulfurization gypsum and steel slag, Constr. Build. Mater. 187 (2018) 1113–1120.

DOI: 10.1016/j.conbuildmat.2018.07.241

[7] Q.T. Phung, N. Maes, D. Jacques, E. Bruneel, I.V. Driessche, G. Ye, G.D. Schutter, Effect of limestone fillers on microstructure and permeability due to carbonation of cement pastes under controlled CO2 pressure conditions, Constr. Build. Mater. 82 (2015) 376–390.

DOI: 10.1016/j.conbuildmat.2015.02.093

[8] V.D. Pizzol, L.M. Mendes, H. Savastano Jr., M. Frías, F.J. Davila, M.A. Cincotto, V.M. John, G.H.D. Tonoli, Mineralogical and microstructural changes promoted by accelerated carbonation and ageing cycles of hybrid fiber–cement composites, Constr. Build. Mater. 68 (2014) 750–756.

DOI: 10.1016/j.conbuildmat.2014.06.055