凝灰岩石粉掺量对活性粉末混凝土性能的影响

The Influence of Tuff Powder Content on the Properties of Reactive Powder Concrete

以0.14水胶比成型活性粉末混凝土(RPC)为基体,采用凝灰岩石粉取代部分胶凝材料制备RPC,研究凝灰岩石粉掺量对RPC抗压强度、抗折强度和微观结构的影响。结果表明:RPC的抗压强度、抗折强度随凝灰岩石粉掺量增加呈下降趋势。凝灰岩石粉在胶凝体系中发挥了一定的火山灰效应和填充效应,改善了RPC的微观结构;掺量为5%凝灰岩石粉掺制备的RPC能满足力学要求,28 d龄期的抗压强度为119 MPa,抗折强度为12.4 MPa,孔隙率最低,且界面区最密实;当凝灰岩石粉掺量超过5%后,对微观结构的改善效果有所下降,当凝灰岩石粉掺量超过20%时,已不利于RPC微观结构的改善。

Reactive powder concrete(RPC)with a water-binder raio of 0.14 was used as the matrix to prepare RPC by replacing part of the cementitious material with tuff powder.The effects of tuff powder content on the compressive strength,flexural strength and microstructure of RPC were studied.The results show that the compressive strength and flexural strength of RPC show a downward trend with the increase of tuff powder content.The tuff powder exerts certain pozzolanic and flling effects in the cementitious system,and improved the microstructure of RPC.The RPC prepared by adding 5%tuff powder can meet the mechanical requirements,the compressive strength at 28 dage is 119 MPa,the flexural strength is 12.4 MPa,the porosity is the lowest,and the interface area is the densest.When the content of tuff powder exceeds 5%,the efct of improving the microstnucture decreases.When the content of tuff rock powder exceeds 20%,it is not conducive to the improvement of RPC microstructure.