Influence of Ultrafine 2CaO·SiO2 Powder on Hydration Properties of Reactive Powder Concrete |
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| Authors: | Hongfang Sun Zishanshan Li Shazim Ali Memon Qiwu Zhang Yaocheng Wang Bing Liu Weiting Xu Feng Xing |
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| Institution: | 1.Guangdong Province Key Laboratory of Durability for Marine Civil Engineering, School of Civil Engineering, Shenzhen University, Shenzhen 518060, Guangdong, China; E-Mails: (H.S.); (Z.L.); (Y.W.); (B.L.);2.Department of Civil Engineering, COMSATS Institute of Information Technology, Abbottabad 22010, Pakistan; E-Mail: ;3.Department of Civil Engineering, Chongqing University, Chongqing 400044, China; E-Mail: |
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| Abstract: | In this research, we assessed the influence of an ultrafine 2CaO·SiO2 powder on the hydration properties of a reactive powder concrete system. The ultrafine powder was manufactured through chemical combustion method. The morphology of ultrafine powder and the development of hydration products in the cement paste prepared with ultrafine powder were investigated by scanning electron microscopy (SEM), mineralogical composition were determined by X-ray diffraction, while the heat release characteristics up to the age of 3 days were investigated by calorimetry. Moreover, the properties of cementitious system in fresh and hardened state (setting time, drying shrinkage, and compressive strength) with 5% ordinary Portland cement replaced by ultrafine powder were evaluated. From SEM micrographs, the particle size of ultrafine powder was found to be up to several hundred nanometers. The hydration product started formulating at the age of 3 days due to slow reacting nature of belitic 2CaO·SiO2. The initial and final setting times were prolonged and no significant difference in drying shrinkage was observed when 5% ordinary Portland cement was replaced by ultrafine powder. Moreover, in comparison to control reactive powder concrete, the reactive powder concrete containing ultrafine powder showed improvement in compressive strength at and above 7 days of testing. Based on above, it can be concluded that the manufactured ultrafine 2CaO·SiO2 powder has the potential to improve the performance of a reactive powder cementitious system. |
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| Keywords: | ultrafine hydration reactive powder concrete microstructure compressive strength |
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