With the rapid rise in our needs and requirements, the amount of waste generated by modern cities is also increasing at an unprecedented rate. This problem is global in nature and most countries around the world need appropriate waste management strategies. These measures include disposal and the 3Rs (reduce, reuse, and recycle). Each of these strategies has its own share of pros and cons. An increasing emphasis is being placed on the application of the 3Rs, especially from the environmental perspective. Construction & demolition (C & D) waste is generated when new infrastructure is built and/or older structures are demolished or renovated. Hundreds of millions of tons of such waste are generated worldwide annually, making it one of the most significant waste generating activities in the world. One way to take care of a significant fraction of this waste is as recycled aggregates (RA), wherein the waste is crushed to the dimensions of coarse and fine aggregates and is used for various activities, most notably in manufacturing of concrete. Other uses may include landfilling, manufacturing of tiles, bricks, pavement blocks, etc. Recently, other types of wastes such as used PET bottles have also been studied as a source of recycled aggregates. This book deals with the various socio-economic, technical, environmental, and policy issues related to the application of various types of recycled aggregates in different countries around the world. This is a continually evolving area of applied research which needs further emphasis not only from researchers, but planners and regulators as well.