Pimenta Teixeira Karine, Perdigão Rocha Isadora, De Sá Carneiro Leticia, Flores Jessica, Dauer Edward A, Ghahremaninezhad Ali
Department of Civil, Architectural and Environmental Engineering, University of Miami, Coral Gables, FL 33146, USA.
Department of Biomedical Engineering, University of Miami, Coral Gables, FL 33146, USA.
Materials (Basel). 2016 Nov 23;9(11):952. doi: 10.3390/ma9110952.
This paper investigates the effect of curing temperature on the hydration, microstructure, compressive strength, and transport of cement pastes modified with TiO₂ nanoparticles. These characteristics of cement pastes were studied using non-evaporable water content measurement, X-ray diffraction (XRD), compressive strength test, electrical resistivity and porosity measurements, and scanning electron microscopy (SEM). It was shown that temperature enhanced the early hydration. The cement pastes cured at elevated temperatures generally showed an increase in compressive strength at an early age compared to the cement paste cured at room temperature, but the strength gain decreased at later ages. The electrical resistivity of the cement pastes cured at elevated temperatures was found to decrease more noticeably at late ages compared to that of the room temperature cured cement paste. SEM examination indicated that hydration product was more uniformly distributed in the microstructure of the cement paste cured at room temperature compared to the cement pastes cured at elevated temperatures. It was observed that high temperature curing decreased the compressive strength and electrical resistivity of the cement pastes at late ages in a more pronounced manner when higher levels of TiO₂ nanoparticles were added.
本文研究了养护温度对用二氧化钛纳米颗粒改性的水泥浆体水化、微观结构、抗压强度和传输性能的影响。采用非蒸发水含量测量、X射线衍射（XRD）、抗压强度试验、电阻率和孔隙率测量以及扫描电子显微镜（SEM）对水泥浆体的这些特性进行了研究。结果表明，温度提高了早期水化。与在室温下养护的水泥浆体相比，在高温下养护的水泥浆体在早期通常表现出抗压强度的增加，但后期强度增长下降。发现与室温养护的水泥浆体相比，在高温下养护的水泥浆体在后期电阻率下降更为明显。SEM检查表明，与在高温下养护的水泥浆体相比，水化产物在室温养护的水泥浆体微观结构中分布更均匀。观察到，当添加较高水平的二氧化钛纳米颗粒时，高温养护在后期更显著地降低了水泥浆体的抗压强度和电阻率。
