研究了不同掺量下氧化石墨烯( GO)对水泥石以及胶砂微观结构和力学性能的影响。含16.5%水的水泥浆、0.05%GO及3倍于水泥的沙子共混物作为添加剂制备成砂浆。通过SEM、液氮吸附仪和一系列标准实验分别对水泥石的微观形态、孔隙结构、抗压抗折强度以及水泥净浆的流动度、黏度、凝结时间进行表征；考察不同GO掺量下水泥水化放热的变化情况。结果表明：GO对水泥浆有显著增稠和促凝作用；GO的掺入可以有效降低水泥的水化放热量；GO对水泥石有显著的增强增韧效果,28天龄期时,GO质量分数为0.05%的水泥石,3、7和28 d抗压强度和抗折强度同比对照组分别增加52.4%、46.5%、40.4%和86.1%、68.5%、90.5%,胶砂的抗压强度和抗折强度同比对照组分别增加43.2%、33%、24.4%和69.4%、106.4%、70.5%；GO在水泥硬化过程中对水泥石中晶体产物的产生有促进作用并能规整晶体的排布而形成针状晶体簇,改善水泥石中的孔结构,降低水泥石中微孔的体积,增加水泥石的密实度,对水泥石有显著地增强增韧效果。
The effect of adding graphene oxide ( GO) to cement on its microstructure and mechanical strength was investigated. A paste of cement (16. 5% of water)and GO (0. 05%) was prepared together with an identical mixture to which sand (3x the weight of the cement) had been added to form a mortar. The fluidity, viscosity and setting time of the mortar and the morphology, pore structure and compressive and flexural strengths of both the hardened cement paste and mortar, were investigated using SEM, nitro-gen adsorption, and fluidity, viscosity, mechanical and hydration tests. The influence of the GO addition on the hydration heat of the cement was also tested. Results show that the addition of GO increases the viscosity, decreases the fluidity and shortens the set-ting time of the mortar. It also reduces the heat of hydration of the cement. The compressive and flexural strengths of the hardened cement paste at different times are increased by the addition of GO. The flexural strength was greater by 86. 1%, 68. 5% and 90. 5% after 3, 7 and 28 days, respectively, and the corresponding compressive strength increases were 52. 4%, 46. 5% and 40. 4% For the hardened mortar, the corresponding increases are 69. 4%, 106. 4% and 70. 5% for flexural strength and 43. 2%, 33% and 24. 4% for compressive strength. The addition of GO promotes hydration, decreases pore volume, accelerates crystallite formation and causes the crystallites to align, which increases the tightness of both the hardened cement paste and mortar.
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