INFLUENCE OF RECYCLED AGGREGATE QUALITY ON CONCRETE PROPERTIES

摘要

Almost all the studies and experiences on recycled concrete agree that the utilization of recycled aggregates in structural concrete should be limited to recycled concrete aggregate, and only recommend the use of the coarse fraction, as the fine fraction worsens the properties of recycled concrete too much. The objective of this work is to study the influence of different percentages of recycled concrete aggregate on concrete properties in order to establish a maximum percentage usable in concrete. In order to standardize structural recycled concrete properties, an intermediate quality recycled aggregate, but suitable enough for structural concrete, has been selected. The following properties have been studied in concretes with 20%, 50% and 100% of recycled coarse aggregate: slump, density, compressive strength, tensile strength, elastic modulus of elasticity and drying shrinkage. In this study, the coefficients to be applied to traditional formulas have been established to foresee recycled concrete properties. The results show that the selected recycled concrete aggregate can unfavorably affect to concrete properties in a larger extent than those established by some international recommendations (Rilem, Netherlands, etc).