石墨混凝土电导率-应变与割线模量-应变关系

Study on Relationship Between Electrical Conductivity-Strain and Deformation Modulus-Strain of Graphite Concrete

目的研究石墨混凝土破坏全过程的力学及电学性能,将这种功能材料用于混凝土结构(如建筑、桥梁、大坝等)的无损自诊断检测预警、车辆质量及速度的测量、电磁屏蔽、采暖、融雪化冰等领域.方法使用刚性试验机,做了石墨混凝土棱柱体试件单轴压缩全过程试验.结果无论在单次还是反复荷载的作用下,混凝土割线模量-应变关系与电导率-应变关系的走势均保持一致.再从导电机理和比拟法两方面进行探讨,找出两种曲线走势相一致的原因,并论证得到.结论即便在出现损伤甚至破裂的情况下导电混凝土电-力仍可相互比拟(可作全过程比拟).并且认为电导率这个本征量与割线模量一样,能够很好地揭示混凝土材料的损伤.

Conductible concrete possesses properties of stress and temperature sensitivity, and can be used as a functional material. It can be applied to the fields of nondestructive tests, early-warning of concrete structures （like buildings, bridges and dams, etc. ）, weight and speed measurement of vehicles, electromagnetic shielding and heating and snow melting, etc. The stiff testing machine has been used for the study of the mechanical and electrical behaviors. Specimens have been tested for their conductivity and mechanical properties in the whole process under single and cyclic loading. The results have shown that the deformation modulus-strain and conductivity-strain relationships are obviously correspondent with each other under both single and cyclic loading. The study analyzes the reasons why the up-and-down trend as shown on the deformation modulus-strain curve conforms to that as shown on the conductivity- strain curve. The conduction mechanism has been discussed and an analogy has been drawn to find the reason why the two keep consistent relationships. Even if a specimen is damaged, it is proved positively that an analogy between the electrical and mechanical fields of the concrete can also be drawn in the whole loading test process of conductible concrete. Like the deformation modulus, the electrical conductivity is such an eigenvalue that it will characterize well the damage of conductible concrete.