应力自感知水泥基复合材料及其传感器的研究进展

State-of-the-art of stress-sensing cement composite material and sensors

应力自感知水泥基复合材料是在传统的水泥或砂浆中添加特定导电材料或纳米材料复合而成的具有压阻效应的材料。利用这类材料的电阻率与其自身压应力存在一定对应关系的特性,可以制成性能独特的应力自感知水泥基复合材料传感器。此类传感器因具有造价低、耐久性好、埋设工艺简单以及与混凝土材料相容性好等特性,有望成为混凝土结构长期健康监测的新一代传感装置。本文作者从原材料选择、搅拌工艺、电阻测试方法以及传感器测试系统等多方面综合评述了应力自感知水泥基复合材料的研究进展。同时指出,为促进其在工程中的应用,对碳纤维水泥石电阻率的离散性、稳定性以及多向约束受力下电阻率的变化曲线等问题都必须进一步深入研究。

The stress-sensing cement composite material, which is mainly composed of special conducting material or nano-particle and traditional cement or mortar, is a new kind of material with piezoresistive effect. Using the special performance of this material that between its specific resistance and compressive stress there is a corresponding relationship, a new kind of sensor can be made. As having character of low cost, high durability and good compatibility with concrete, sensors made of the stress-sensing cement composite material have great potential to be used as long time health monitors of concrete structures. In this paper, the progress in stress- sensing cement composite materials, such as treating and selecting of the raw material, mixing technology, testing method of specific resistance, and testing system of the stress-sensing cement sensor, was summarized. And the problems, i.e. stability and discreteness of specific resistance and specific resistance＇s changing rules under multiaxial stresses and so on, should be further resolved so as to promote their applications to practical engineering.