混凝土早龄期回弹强度影响因素数值分析

Numerical Analysis of Factors Influencing the Rebound Strength of Concrete in Early Age

公路工程中常用回弹法检测混凝土实体强度,但回弹法测得结果本质上有别于混凝土立方体抗压强度,影响因素颇多.为了了解不同因素对回弹强度的影响规律,采用不同的水胶比、浆体体积、粉煤灰掺量等,制备了26组混凝土,对比立方体抗压强度和回弹法换算强度之间的关系,同时推导了回弹强度预测公式,通过数值计算分析了回弹强度影响因素.结果表明:回弹换算强度一般低于立方体抗压强度;影响回弹强度的主要因素是浆体体积、掺合料用量、水胶比、水泥强度;随着浆体体积增加、水胶比增大、掺合料用量增加,回弹强度会降低,水泥强度增加,回弹强度会提高.

In highway engineering,rebound method is often used to detect the concrete solid strength,but the result of rebound method is different from the concrete cube compressive strength in essence,and there are many influencing factors.In order to understand the influence law of diflerent factors on rebound strength,26 groups of concrete were prepared by using different water binder ratio,slurry volume,fly ash content,etc.the relationship between cube compressive strength and rebound method converted strength was compared.At the same time,the prediction formula of rebound strength was deduced,and the influencing factors of rebound strength were analyzed by numerical calculation.The results show that the rebound conversion strength is generally lower than the cube compressive strength;the main factors affecting the rebound strength are the volume of slurry,the amount of admixture,the water binder ratio and the cement strength.With the increase of the volume of slurry,water binder ratio and the amount of admixture,rebound strength will decrease.And if cement strength increase,rebound strength will increase too.