Limestone powder and fly ash microbeads were used as mineral admixtures to adjust the properties of ultra high performance wet-joint concrete.The effects of limestone powder and fly ash microbeads on rheological properties,mechanical properties,shrinkage properties and impermeability of ultra high performance wet-joint concrete were studied by setting different mixing ratios.In addition,the hydration performance of ultra high performance wet-joint concrete was analyzed by hydration heat.The results show that when limestone powder is higher than 30％(mass fraction),with the increase content of limestone powder,the plastic viscosity of ultra high performance wet-joint concrete increases first and then decreases.The plastic viscosity of concrete is reduced by 38.0％when added with 50％limestone powder and 50％(mass fraction)fly ash microbeads.The addition of limestone powder promotes the early hydration of cement and improves the early compressive strength of ultra high performance wet-joint concrete,and the maximum growth rate of 3 d compressive strength is 11.6％.The autogenous shrinkage of ultra high performance wet-joint concrete is reduced by adding limestone powder and fly ash microbeads.The impermeability of ultra high performance wet-joint concrete is the best when the content of limestone powder is 30％,and the 28 d chloride ion diffusion coefficient is 0.15 x 10-12 m2/s.
维普
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