基于配合比设计的混凝土强度影响因素灰关联分析

Grey relational analysis of influencing factors of concretestrength based on mix proportion design

为研究混凝土配合比设计因素对混凝土强度影响的敏感性,实现混凝土配比优化设计以及对施工的指导作用,本文以成资渝高速公路TJ2标项目为例,基于不同配合制备5组混凝土,以水胶比、砂率、坍落度作为影响因素,引入灰关联分析法,分析各因素与7d和28d抗压强度之间的关联度。结果表明:各因素对混凝土强度影响的灰关联度排序为坍落度>砂率>水胶比,即坍落度对混凝土强度的影响最为敏感。随着坍落度的增加,混凝土强度呈现出先增加后减小的变化规律,并且当坍落度为195mm时混凝土强度达到最大值。砂率对混凝土强度具有两方面影响,过大或过小均不利于混凝土强度的形成,以35MPa为分界点,砂率对7d和28d混凝土强度变化的影响速率有所不同。随着水胶比的增大,混凝土强度呈递减的规律。

In order to study the sensitivity of concrete mix proportion design factors to the influence of concrete strength,realize the optimal design of concrete mix proportion and guide the construction.Taking the Tj2 bid project of Chengdu Ziyang Chongqing Expressway as an example,five groups of concrete are prepared based on different mixes.Taking water binder ratio,sand ratio and slump as influencing factors,the grey correlation analysis method is introduced to analyze the correlation between each factor and 7d and 28d compressive strength.The results show that the grey correlation degree of the influence of various factors on concrete strength is slump>sand ratio>water binder ratio,that is,slump is the most sensitive to the influence of concrete strength.With the increase of slump,the concrete strength increases first and then decreases,and the concrete strength reaches the maximum when the slump is 195mm.Sand ratio has two effects on concrete strength.Too large or too small is not conducive to the formation of concrete strength.Taking 35MPa as the dividing point,the influence rate of sand ratio on the change of concrete strength at 7d and 28d is different.With the increase of water binder ratio,the strength of concrete decreases.