Properties of self-compacting concrete made of recycled aggregates and various mineral additives

Abstract

By its technology, Self-Compacting Concrete does not need compaction by vibration. Compaction of this concrete, in every part, or in every corner of the formwork, including its hardly available parts, is done without any external forces except its own weight. These properties are achieved by adding superplasticizers, commonly with new Viscosity Modification Admixtures, or/and determined amount of powders. It is possible to use different mineral additions, where the use of those which are industrial by - products (like fly ash) has multiple environmental benefits. Lack of natural aggregate in urban areas and increasing distance between deposits of high - quality natural aggregate and building sites, forced building contractors to analyze possibility of replacing of natural aggregate with recycled materials (masonry, slag, concrete, etc.). On the other hand, huge amount of old concrete exists in urban areas and its removal and deposition is a big ecological problem. Aim of this paper is analysis of properties and technology of Self-Compacting Concrete with different mineral additions (lime, fly ash and silica fume), natural and recycled aggregate, considering mixes without recycled aggregate, with third recycled fraction, and with second and third recycled fractions.

Keywords

• self - compacting concrete
• lime
• fly ash
• silica fume
• recycled aggregate
• ecological aspect