The effects of the roughness(Ⅰ,Ⅱ)of bonding surface and the age(0,45,90,210 and 330 d)of sulphate erosion on the impermeability of the bonding surface of ultra-high performance concrete-normal concrete(UHPC-NC)specimens were investigated,and the microscopic mechanism was analyzed.The results show that,regardless of the roughness of the bonding surface,with the increase of the erosion age,the impermeability of the bonding surface of UHPC-NC specimens basically shows a trend of first increasing and then decreasing,and the impermeability of the bonding surface of UHPC-NC specimens is basically the best when the erosion age is 90 d.Overall,the impermeability of the bonding surface of UHPC-NC specimens with roughness Ⅱ is better than that of the UHPC-NC specimens with roughness Ⅰ.Under the erosion of sulphate,the expansive corrosion products(gypsum,ettringite)are generated in the internal pores of the UHPC-NC specimen.When excessive,it can cause an increase in the internal tensile stress of the concrete,resulting in expansion cracks,and thus weakening the impermeability of the bonding surface of the UHPC-NC specimens.
维普
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