Microstructure and durability properties of cement mortars containing nano-TiO2 and rice husk ash (Retracted Article)
Microstructure and durability properties of cement mortars containing nano-TiO2 and rice husk ash (Retracted Article)
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DOI：
10.1016/j.conbuildmat.2016.03.136
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发表时间：
2016-07-01
影响因子：
7.4
通讯作者：
Ranjbar, Malek Mohammad
中科院分区：
文献类型：
--
作者：
Mohseni, Ehsan;Naseri, Farzad;Ranjbar, Malek Mohammad
在本研究中，研究了在水泥砂浆中加入两种补充胶凝材料：农业废弃物灰即稻壳灰（RHA）和纳米tio2 （NT）的硬化复合材料的抗压强度、吸水率、电阻率、快速氯离子渗透试验（RCPT）和超声脉冲速度（UPV）试验。采用扫描电镜（SEM）和x射线衍射（XRD）分析了复合材料的界面过渡区（ITZ）和微观结构。抗压强度结果表明，含有NT的样品有了实质性的改善，并且通过使用高达10%的RHA作为水泥的替代品，观察到砂浆性能略有增加。然而，二元混合物在强度发展和耐久性方面表现出最好的结果。还可以看到，砂浆中15% RHA和5% NT的组合对耐久性性能有积极的贡献。XRD分析表明，添加NT后，Alite相和Belite相强度降低，portlandite相强度达到新的峰值。SEM显微图显示，含有NT的砂浆广泛分布，孔隙结构密集，提高了试样的强度和耐久性。因此，RHA和NT的混合可以提高砂浆的强度和耐久性。总的来说，考虑到经济效益和硬化性能，15% RHA和5% NT似乎可以被认为是合适的替代品。(C) 2016 Elsevier Ltd.版权所有。
In the present study, Compressive strength, water absorption, electrical resistivity, Rapid Chloride Permeability Test (RCPT) and Ultrasonic Pulse Velocity (UPV) tests of the hardened composites incorporating two supplementary cementitious materials: agricultural waste ash namely as rice husk ash (RHA) and nano-TiO2 (NT) in cement mortars were investigated. The interfacial transition zone (ITZ) and the microstructure were studied by using Scanning Electron Microscope (SEM) and X-ray Diffraction (XRD) analysis, respectively. Compressive strength results showed a substantial improvement in samples containing NT and also a slight increase in mortar performance was observed by using up to 10 wt% of RHA as a replacement of cement. However, binary mixtures displayed the best results for strength development and durability. It is also seen that a combination of 15% RHA and 5% NT in mortar led to a positive contribution to durability properties. XRD analysis showed that intensity of Alite and Belite phases decreased and new peak of portlandite achieved with the addition of NT. The SEM micrographs illustrated the widespread distribution of mortars containing NT with packed pore structures which resulted in promoting of strength and durability of specimens. Consequently, the combined mixture of RHA and NT has led to the enhancement of strength and durability properties of mortars. In general, it seems that 15% RHA and 5% NT can be considered as a suitable replacement regarding to the economic efficiency and hardened properties. (C) 2016 Elsevier Ltd. All rights reserved.