ABSTRACT
Among the three ways of recycling fine recycled aggregate (FRA) in the cement and concrete process, the first one is the use it as components of clinker raw mix raw does not raise any question in terms of standardization as long as, through burning process, the result of it will give, by design, a Portland clinker with the expected mineralogical composition and the subsequent usage properties (Chapter 4). The second and third ways are, respectively, the incorporation of FRA as cement main constituents other than clinker and considering FRA as concrete addition or supplementary cementitious material (SCM) after grinding; they are evaluated in this chapter. The first part of this chapter is devoted to the evaluation of the physicochemical properties of composed Portland cements, produced at a semi-pilot scale obtained by replacement of limestone, considering their mineral composition. The FRA can be considered as a serious potential candidate to be recognized as cement main constituent. In the second 84part of the chapter, the evaluation of the opportunity to use the fine fraction extracted from crushed demolition concretes is presented considering FRA as mineral additions in binder-based mortars or concrete mixes. Two types of fines particles are described and were studied: fines particles from dust collector, obtained during the process of recycled concrete crushing for the production of fine and coarse aggregates and fines particles obtained from the grinding of fine recycled aggregate. The work includes the characterization of these materials, the study of their hydraulic and pozzolanic activity, and their effect on the properties of fresh and hardened mortars when used in replacement of a fraction of Portland cement. The FRA can be considered as type I addition (filler) and even as type II addition (pozzolanic), since it was observed that they seem to have a long-term binding activity.
