基于半经验的UHPC配合比设计方法

UHPC Mix Design Method Based on Semi⁃quantitative

超高性能混凝土(UHPC)是国内外学者当下关注的热点,但对于UHPC配合比设计目前没有明确的规范。采用理论分析和试验相结合的方法提出一种基于半经验的UHPC配合比设计,首先按照参考文献胶凝材料配合比配制胶砂试件并测出其28 d抗压强度,其次使用Matlab拟合工具箱拟合UHPC 28 d抗压强度与水胶比、胶凝材料28 d强度的定量关系;再采用Mathematica拟合胶凝材料强度与水泥胶砂强度的关系,通过拟合公式确定水胶比,依据最大密实理论确定骨料的掺加比例,最后通过全体积计算方法确定UHPC配合比。在这之后对基于半经验的UHPC配合比设计方法进行了验证,测试了蒸养条件下的抗压强度与抗折强度。结果表明:根据拟合公式计算的理论配制强度与实际测试的抗压强度接近,其差值在抗压强度测量误差范围内,该配合比设计方法具有较好的可靠性,此方法为广大工作者设计UHPC提供了一种新思路。

Ultra⁃high performance concrete(UHPC)is currently a hot spot for domestic and foreign scholars,but there is no explicit specification for the UHPC mix ratio design.This papercomes up with a semi-empirical UHPC mix design based on theoretical analysis and experiment.Firstly,the cement sand specimen was prepared according to the mix ratio of the cementitious material in reference,and then 28 d compressive strength was measured.Secondly,using Matlab fitting toolbox to fit UHPC the quantitative relationship between preparation strength and water⁃binder ratio and cementitious material strength.Thirdly,fitting the relationship between the strength of cementitious material and the strength of cement sand through Mathematica.Fourthly,the water⁃binder ratio is determined by the fitting formula.Then according to the maximum density theory to determine the proportion of aggregate addition.Finally,the UHPC mix ratio is determined by the whole product calculation method.After that,the semi⁃empirical UHPC mix ratio design method is verified;we tested the compressive strength and flexural strength of 28 d under steaming conditions.The results show that the theoretical strength calculated according to the fitting formula is close to the compressive strength measured in practice.The difference is within the error range of compressive strength measurement.The mix ratio design method has good reliability.And this method provides a new way for workers to design UHPC.