养护方法对含铁尾矿粉的高性能混凝土力学、耐久和微观结构影响

Effects of Curing Conditions on Mechanical,Durability,and Microstructural Properties of UHPC Incorporating Iron Tailing Powder

混凝土的高性能化和绿色化对原材料品质提出很高要求,而我国大量铁尾矿工业废弃物的处置是当下急需解决的问题。基于此,研究了标准养护、45℃温水养护与90℃蒸汽养护3种养护方法对含铁尾矿粉的高性能混凝土力学性能(抗压和抗折强度)、收缩性能和微观结构(组成成分和微观形貌)影响。结果表明,含15%铁尾矿粉的混凝土力学性能达到最佳值,温水养护和蒸汽养护可进一步提升其力学性能。此外,引入细小的铁尾矿粉可促进水泥颗粒水化,从而形成致密的微观结构,但铁尾矿粉自身活性有限,在蒸汽养护条件下可参与水化反应。研究成果可进一步开发绿色、低成本的高性能混凝土。

The high performance and greenness of concrete put forward high requirements on the quality of raw materials,and the disposal of a large amount of industrial wastes from iron tailings in my country is a problem that needs to be solved urgently.This paper studies the mechanical properties(compressive and flexural strength)and shrinkage of iron-containing tailings powder on the three curing systems of standard curing,45℃warm water curing and 90℃autoclaved curing.Performance and micro properties(composition and micro morphology)influence.The steam curing regime stimulates the activity of ITP,refines the microstructure,and enhances their early-age strength.This study demonstrates the potential of replacing Portland cement(PC)with ITP in UHPC production.The outcomes of this study can further develop green,low-cost of UHPC.