This book is about the study of recycled aggregate. Recycling of aggregate is a process in which used aggregate is reused for new construction. Use of recycled aggregate is not very common in India and other developing countries. There is a huge requirement of the aggregate because of fast development in the infrastructure area. In order to reduce the usage of fresh aggregate, the recycled aggregate can be used as a replacement material. Recycled aggregate used in this study is obtained from the debris of dismantled roads. Various properties find out by comparison of fresh and recycled aggregate.