混凝土密实度发展规律的混沌特征评价

Assessment of chaos on the law of development of compactness in concrete

通过监测不同振捣时间处理的混凝土30 d内的超声声速值以及抗压强度试验,对混凝土超声声速与抗压强度进行了回归分析,并运用混沌特征参数Lyapunov指数分析了不同密实度的混凝土超声声速值随时间的发展规律。结果表明:混凝土的初始密实度影响超声声速值与抗压强度回归相关性的高低,初始密实程度大,相关性高;经振捣处理的混凝土的超声声速信号的发展过程最大Lyapunov指数均为负值,不属于混沌特征范围,而未经振捣处理的混凝土超声声速的发展过程最大Lyapunov指数为正数,表现出混沌特征。

The regression analysis of the ultrasonic velocity and the compressive strength data was performed assisted by the tests of ul- trasonic detection and the compressive strength which carded out in the 30 days of the different vibrating time processed-concrete and the law of development that the ultrasonic velocity along with the curing time of three different initial degree density of concrete was investi- gated by analyzing the Lyapunov exponents in this paper.The results showed that the initial degree density indeed impact the correction of the regression between the ultrasonic velocity and the compressive strength, in details, the correlation between the two is more higher when the initial degree density of concrete is more uniform and denser.In addition, the Lyapunov exponents of the ultrasonic velocity along with the curing time are all negative values in the vibrating concrete which indicated that chaotic analyzed system do not come under the scope of chaos characteristic.While in the non-vibrating concrete, the Lyapunov exponents of the ultrasonic velocity along with the curing time is positive value which indicated that chaotic analyzed system belong to the scope of chaotic characteristic.