纳米α-Al2O3的合成及其对混凝土力学性能的影响

Synthesis of Nano α-Al2O3 and Influence on Mechanical Properties of Concrete

采用溶胶凝胶法合成α-Al2O3纳米粉,利用DSC-TG、XRD及TEM对α-Al2O3纳米粉的煅烧温度、晶相及微观形貌进行表征。将该纳米粉掺入水泥混凝土,借助万能试验机研究纳米α-Al2O3粉对混凝土力学性能的影响。结果表明:干凝胶前驱体经1050℃煅烧得到结晶良好的α-Al2O3纳米粉;纳米α-Al2O3粉的适量添加使混凝土的抗压强度、抗折强度及劈裂抗拉强度均有所提高,对劈裂抗拉强度的提高最为显著;纳米α-Al2O3粉的合理掺量在2.0%~2.5%之间;纳米α-Al2O3粉的添加有利于降低混凝土的脆性。

Nano α-Al2O3 was prepared by sol-gel method.The calcination temperature,crystalline phase and microscopic morphology of nano-powder were characterized by DSC-TG,XRD and TEM,respectively.The nano-powder was incorporated into cement concrete.The influence of nano α-Al2O3 on mechanical properties of concrete was measured by universal testing machine.The results show that crystalline α-Al2O3 nano-powder is obtained after calcination at 1050 ℃;The compressive strength,flexural strength and splitting tensile strength of concrete are all improved by proper amount addition of nano α-Al2O3 powder,and the splitting tensile strength is the highest degree of improvement;the suitable dosage of α-Al2O3 nano-powder is between 2.0%and 2.5%;the brittleness of concrete is reduced by addition of α-Al2O3 nano-powder.