Effect of Lightweight Aggregate Pre-wetting on Microstructure and Permeability of Mixed Aggregate Concrete
来源期刊：Journal Of Wuhan University Of Technology Materials Science Edition2009年第5期
论文作者：葛勇
文章页码：838 - 842
摘 要：The influence of lightweight aggregate （LWA） pre-wetting on the chemical bound water and pore structure of the paste around aggregate as well as concrete permeability were investi-gated. The results show that, in early age the dry LWA has significant effect on the formation of dense paste around it and improving the concrete impermeability. However the prewetted LWA has strong water-releasing effect in later age, which increases the hydration degree of the paste around it, and makes the adjacent paste develop a structure with low porosity and finer aperture, furthermore the concrete impermeability can be improved. It is suggested that, as for concrete with low durability requirement, the LWA without pre-wetting treatment can be used as long as meet the workability re-quirement of fresh concrete, the good impermeability of concrete can be gained as well. As for con-crete with high durability requirement, the prewetted LWA should be used, and the pre-wetting time should be extended as long as possible, in order to optimize the concrete structure in long term, and improve the concrete durability.
葛勇
School of Materials Science and Engineering,Harbin Institute of Technology
摘 要：The influence of lightweight aggregate （LWA） pre-wetting on the chemical bound water and pore structure of the paste around aggregate as well as concrete permeability were investi-gated. The results show that, in early age the dry LWA has significant effect on the formation of dense paste around it and improving the concrete impermeability. However the prewetted LWA has strong water-releasing effect in later age, which increases the hydration degree of the paste around it, and makes the adjacent paste develop a structure with low porosity and finer aperture, furthermore the concrete impermeability can be improved. It is suggested that, as for concrete with low durability requirement, the LWA without pre-wetting treatment can be used as long as meet the workability re-quirement of fresh concrete, the good impermeability of concrete can be gained as well. As for con-crete with high durability requirement, the prewetted LWA should be used, and the pre-wetting time should be extended as long as possible, in order to optimize the concrete structure in long term, and improve the concrete durability.
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