Self-Compacting Concrete with Low Binder Content and Recycled Aggregates - Economical or Ecological Solution?

Abstract

Despite the fact that the self-consolidating concrete is present on the market since the 1990s, it still faces a number of problems that limit its use in many countries. In Poland, in addition to economic barriers (the standard self-compacting concrete is much more expensive than standard concrete, which is most obtainable at low classes such as C16/20 and C20/25), there are also problems with a higher shrinkage resulting from the large amounts of grout There are also frequent problems with a high viscosity of the standard self-consolidating concrete, limiting the areas of its use. Development of a concrete technology and, in particular, the new generation of stabilizers (VMA) produced an alternative to the traditional self-consolidating concretes, i.e. the self-consolidating concretes with a low binder content - less than 380 kg/m3 , or even down to 315 kg/m3 . The low binder content in the new generation of the self-consolidating concretes, comparable to the binder content of standard products, makes them more economically competitive. The low viscosity of these mixtures result in much easier application, and the contraction rate lower in comparison to the standard self-consolidating concrete, which make them ideal substitutes of standard concretes. In the age of sustainable development, the requirements of the certification related to multi-criteria evaluation system such as LEED, BREEAM and DGNB, considerable importance to the issue of CO2 emission reduction. The production of self-compacting concrete with low binder content and recycled aggregates result in lower CO2 emissions than production of other self-consolidating concretes with high binder content. The use of recycled aggregates coupled with reducing the binder content make the self-compacting concrete more attractive in terms of their environmental impact. This solution allows for reduction in both the heat of hydration due to low cement content, and also for higher scores in multi-criteria evaluation building systems, due to the use of waste materials. This paper attempts to present the advantages and disadvantages of economical and ecological analyze of waste material usage such as recycled aggregates in SCC solutions.