Abstract

Concrete is one of the most widely used engineering materials in the field of civil engineering. With the extensive use of concrete structures, people have paid more and more attention to the durability of concrete structures. Nowadays, the research on the durability of concrete structures has become a hotspot in the field of civil engineering academics.The purpose of this article is to study the influence of nanomaterials on the physical mechanics and durability of concrete composite bridge piers, and to prepare nano-concrete by mixing appropriate number of nanomaterials (nanoSiO₂, liquid nanoSiO₂ and nanoFe₂O₃) into the concrete composite bridge piers. The physical mechanics and durability of nano-concrete under the combined action of CO₂ erosion and AAR. The results show that the 28-day compressive strength test of nano-concrete is carried out to analyze the effect of the type and amount of nano-materials on the 28-day compressive strength of concrete. The test results show that the concrete has the highest compressive strength when the content of nano-SiO₂, liquid nano-SiO₂ and nano-Fe₂O₃ is 2%, 2% and 1%, respectively. The effect of nano-SiO₂ on the durability of concrete under the effect of AAR is better than that of liquid nano-SiO₂. Therefore, nanomaterials can effectively improve the pore structure of concrete, and participate in the hydration of concrete, thereby improving the durability of concrete such as frost resistance, impermeability, erosion resistance, and corrosion resistance.

摘要

混凝土是土木工程领域应用最广泛的工程材料之一。随着混凝土结构的广泛使用，人们越来越关注混凝土结构的耐久性。目前，混凝土结构耐久性研究已成为土木工程学术领域的一个热点。本文旨在研究纳米材料对混凝土组合桥墩物理力学和耐久性的影响，并制备纳米材料。 -通过混合适当数量的纳米材料（纳米SiO ₂、液态纳米SiO ₂和纳米Fe ₂ O _{3 ）}制成混凝土) 进入混凝土组合桥墩。CO ₂侵蚀和AAR共同作用下纳米混凝土的物理力学和耐久性。结果表明，通过纳米混凝土28天抗压强度试验，分析纳米材料种类和用量对混凝土28天抗压强度的影响。试验结果表明，当纳米SiO ₂、液态纳米SiO ₂和纳米Fe ₂ O ₃的含量_分别为2%、2%和1%时，混凝土的抗压强度最高。纳米SiO ₂在AAR作用下对混凝土耐久性的影响优于液态纳米SiO ₂. 因此，纳米材料可以有效改善混凝土的孔隙结构，参与混凝土的水化，从而提高混凝土的抗冻、抗渗、抗冲刷、抗腐蚀等耐久性。