Paper by HENDRIKS from ISCR 5th 1986 Aachen Germany
In che paper, results are presented of laboratory research and applications in practice of concrete and masonry waste as aggregates for concrete. In a thorough study the amounts, composicion and relevant properties of the waste were investigated. Based on the results of tests in the laboratory and of full scale, recommendations were made for optimal processing in order to prepare aggregates Erom the waste with an acceptable and constant quality. With a combination of crushing, sieving, washing and magnet separation, an aggregate was obtained with an amount of impurities that was negligible (less than 0.1% m/m). Investigation of the properties of concrete made with these aggregates resulted in information concerning strength, workability, long term strength, creep, shrinkage, modulus of elasticity and frost resistance, which was used for design calculations of several types of concrete constructions. The results were also used to prepare a provisional specification for the use of concrete and masonry waste aggregates in all classes of both non-reinforced and reinforced concrete; this specification is at present the base for practical applications. In the last few years, concrete was applied in several road and airfield constructions in which constructions concrete waste was applied as an aggregate. From a technical as well as an economical point of view, the results are successful.