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

The st ress-sensing cement composite material , which is mainly composed of special conducting materialor nano-particle and t raditional cement or mortar , is a new kind of material with piezoresistive effect . Using the special performance of this material that between it s specific resistance and compressive st ress there is a correspondingrelationship , 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 st ress-sensing cement composite material have great potential to be used aslong time health monitors of concrete st ructures. In this paper , the progress in st resssensing cement compositematerials , such as t reating and selecting of the raw material , mixing technology , testing method of specific resistance , and testing system of the st ress-sensing cement sensor , was summarized. And the problems , i. e. stabilityand discreteness of specific resistance and specific resistanceps changing rules under multiaxial st resses and so on ,should be further resolved so as to promote their applications to practical engineering.