Three designs for the internal release of sealants, adhesives, and waterproofing chemicals into concrete to reduce permeability

Various types of hazardous wastes need engineered barriers to prevent outflow. Concrete is a brittle and porous material, which changes dramatically over its lifetime. In order to design waste barriers using any type of concrete, the most effective intervention occurs at the time when it is needed during the life of the material and at the location undergoing distress. Internally placed encapsulators containing sealants, adhesives, and waterproofing are designed to release these chemicals where and when they are needed. Optimizing for durability requires an understanding of the timing and location of release. In all of the cases, brittle fibers containing adhesives or sealants release the chemicals where and when the matrix cracks, causing the fiber to crack and release chemicals. Research from over a decade is presented with special emphasis on permeability, cracking, and data and results from field tests. (C) 2001 Elsevier Science Ltd. All rights reserved.