1 School of Materials Science and Engineering, Southeast University, Nanjing 211189, China 2 Research Center of Greening Building & Construction Materials, Southeast University, Nanjing 211189, China 3 Key Laboratory of Microbial Bio-mineralization Technology, China Construction Materials Industry, Nanjing 211189, China 4 Jiangsu Key Laboratory of Construction Materials, Nanjing 211189, China
Abstract: Glass-fiber reinforced cement (GRC) products are one of the most widely used cement-based decorative materials on account of low weight, easy installation, high strength, and capability of being precast. An important factor restricting the use of GRC products is the white substances separated on the surface when serving in a drying-wetting cycle circumstance, that is efflorescence. The main methods to solve the problem of efflorescence include adding superfine aggregate, surface superhydrophobic treatment, and so on. These methods do not fundamentally solve the problem from the material. In this work, the microbial anti-efflorescence agent was used to improve the anti-efflorescence property of GRC products, which was based on bio-mineralization technology. The microbial anti-efflorescence agent can fix the Ca2+ inside the products, thus preventing it from moving to the surface with water and leading to efflorescence. The results showed that the efflorescence area ratio could significantly decrease to around 3% with the agent. The effects of glass-fiber on the anti-efflorescence property of GRC were also studied. X-CT and MIP tests showed that the effects of both microbial anti-efflorescence agent and glass-fiber on the anti-efflorescence property of GRC were related to the change of pore structure. Besides, the measuring method of the anti-efflorescence property was modified, and a new indicator, efflorescence uniformity, was proposed in this work.