关键词: MgO膨胀剂, 混凝土, 原材料, 自生体积变形

Abstract:

The autogenous volume deformation is one of the most important performances of MgO concrete. The influences of MgO expansion agent types and amount, cement types, aggregates types as well as the fly ash amount on autogenous volume deformation of MgO concrete with 1400d curing age were systematically investigated. The research results indicated that the autogenous volume deformation tended to stable in approximately 2 years without retraction when 4% to 6% of MgO with reactivity time ranging from 50s to 200s was doped. The MgO content in cement concrete cannot accurately reflect the periclase content that generates effective expansion. The autogenous volume deformation and long-term water absorption of aggregates are correlated well, namely the autogenous volume decreased with the increase of water absorption of aggregates. 

Key words: MgO expansion agent, concrete, raw materials, autogenous volume deformation