【摘要】 利用自制的MgO膨胀剂,制备了C50氧化镁微膨胀混凝土,并对其抗压强度、安定性、耐久性能、自生体积变形、徐变性能及其与钢管变形的协调性进行了研究.结果表明,外掺约6%(质量分数,下同)的MgO对混凝土的抗压强度不会产生不利影响;与普通混凝土相比,C50氧化镁微膨胀混凝土的徐变度增加了10%~20%,确保其安定性的MgO外掺量为不超过8%;外掺MgO使混凝土结构更加密实,提高了混凝土的抗渗性和抗冻性;C50氧化镁微膨胀混凝土具有良好的延迟微膨胀性能且自生体积膨胀稳定;外掺6%MgO可使混凝土与钢管的变形保持较好的协调.更多还原

【Abstract】 C50 mangnesium oxide micro-expanded concrete was prepared using a self-made MgO expansive agent.The properties including mechanical properties,soundness,durability,autologous volumetric deformation,creep behavior and coordination with tube deformation were investigated.The results show that mixing with 6%(by mass) MgO has no adverse effect on the mechanical properties of concrete;to ensure soundness the MgO content should be less than 8%;the creep degree increases by about 10%～20% for magnesium oxide micro-expanded concrete compared with ordinary concrete;the resistance to permeability and the resistance to freezing can be further improved due to more compact structure of concrete mixed with MgO.The autologous volumetric deformation of magnesium oxide microexpanded concrete is stable and favorably delays micro-expansion characteristic;the favorable coordination between concrete deformation and tube deformation can be obtained by adding 6% MgO.更多还原