Conceptual design of super environment-conscious intelligent composites incorporated with life-cycle program of self-repair and self-collapse and application for environment-conscious interior planning in buildings

Abstract

Super environment-conscious intelligent composite materials incorporated with life-cycle program of self-repair during in service and self-collapse after designed service life are proposed. One example is carbon short-cut fiber reinforced composites (CFRC) incorporated into matrix mortar with numerous two kinds of micro capsules imbedded with two smaller capsules containing nanometer-size reacting particle (calcium oxide (CaO) or cement) and initiating one (highly water-containing resin particle). These double capsules are incorporated during mixing mortar and fiber as chemical admixture, but they are stably dispersed, not breaking during in service of composites. By triggering these double capsules by external electromagnetic wave having two different frequencies, these capsules are broken, and chemical reaction occurs. As the results, selfrepair is made to occur in the crack part during in service by the rather mild hydration reaction of cement, and self-collapse after designed service life by the rapid expansive hydration reaction of CaO. These cement composites are intelligent due to the appropriate response to the controlled external electromagnetic trigger, and environment-friendly due to the elongation of service life by self-repair, and the easiness of demolition and recycling by self-collapse. The same concept is also applied to carbon continuous fiber reinforced plastic reinforced concrete (CFRPRC). Other than double microcapsules, glass optical fibers are also imbedded into matrix resin of FRP. By detecting the change of electric resistance of CFRP, we can predict the collapse. By triggering the embedded double capsules, self-repair and self-collapse are made to occur. These pseudobiological functions of self-repair and self-collapse are also incorporated into base concrete. These CFRPRC are enough to become intelligent and environment-friendly. By using well designed these super environment-conscious intelligent composites, I try to realize environment-conscious interior planning in which non-adhesive, but joint or set-in type interior construction are considered. © 2005 The Japan Institute of Metals.