规模化拌合超高性能混凝土流动性研究

Research on the Liquidity of Scale Mixed Ultra-High Performance Concrete

超高性能混凝土(UHPC)具备高工作性、高强度、高韧性和高耐久性等优越性能,可满足土木工程轻量化、高层化、大跨化和高耐久化的要求,应用前景广阔。然而UHPC的应用受其规模化制备条件限制。通过改变搅拌机型制和搅拌制度,研究不同搅拌机型制和搅拌制度对UHPC拌合物工作性的影响,分析新拌UHPC物理性能及其硬化后力学性能,结果表明:搅拌机进料容量、搅拌方式对UHPC流动性及抗压强度的影响甚微;延长搅拌时间能够提升拌合物的流动性,但是搅拌超过9 min时,会因物料分布失稳而对力学性能带来负面影响。

Ultra-high performance concrete(UHPC)has high workability,strengthened mechanical properties,high toughness and remarkable durability,which has met the requirements of structural element with lightweight,high rise,large span and high durability.However,the application of UHPC is limited by its scale preparation conditions.In this paper,by changing the mixer model and mixing time,the workability of fresh UHPC was studied,and the mechanical properties of UHPC after hardened were analyzed.The results show that the feeding capacity and mixing mode have little effect on the fluidity and compressive strength of UHPC.Prolonging the mixing time can improve the fluidity of the mixture,but when mixing for more than 9 minutes,it will have a negative impact on the mechanical properties due to the instability of material distribution.