Completely recyclable concrete of aggregate-recovery type by using microwave heating technology

Title: Completely recyclable concrete of aggregate-recovery type by using microwave heating technology
Author(s): T. Noguchi, R. Kitagaki, H. Nagai and M. Tsujino
Paper category : conference
Book title: 2nd International RILEM Conference on Progress of Recycling in the Built Environment
Editor(s): V.M. John, E. Vazquez, S.C. Angulo, C. Ulsen
e-ISBN: 978-2-35158-122-3
Publisher: RILEM Publications SARL
Publication year: 2011
Pages: 333 - 343
Total Pages: 11
Nb references: 6
Language: English

Abstract: Concrete is the most widely consumed construction material, which is expected to serve as a wastebasket for industrial by-products but will generate a lot of waste in the future while currently most concrete waste is recycled as road bottoming and backfilling. Closed-loop recycling systems for concrete, therefore, will be one of the key issues in establishing a resource-recycling society.

Several methods to retrieve aggregates from concrete with high quality have been eagerly developed in Japan. However, some methods produce approximately 10 times amount of CO2 emission to retrieve aggregates comparing with virgin aggregate production, and another cannot control the quality of the retrieved aggregates, which might cause the decrease of concrete performance. In this research, the new method is developed, which accomplishes low CO2 emission in retrieving process and low water absorption of the retrieved aggregate, as well as better mechanical performance of concrete than concrete with virgin aggregates owing to coating the surface of the aggregates with compounds of a dielectric material and pozzolan, which respectively contribute to being heated selectively and efficiently from the outside by microwave radiation so as to easily recover the original aggregate and reinforcing the bond strength between the aggregates and cement matrix.

Online publication: 2012-02-08
Publication type : full_text
Public price (Euros): 0.00