Environmentally friendly material solutions in the technology of autoclaved aerated concrete

Abstract

Autoclaved aerated concrete is an environmentally friendly material. However, the demands of the modern world and, above all, care for the future, necessitate the search for new solutions to minimise negative environmental effects. This paper presents selected solutions for the use of waste materials and by-products from other techniques in autoclaved aerated concrete production, taking into account potential risks and limitations. Attention was also drawn to the use of aerated concrete waste in other methods, primarily as a cement substitute, or concrete additive. The paper is selective in nature due to its volume, but the main purpose is to present trends and directions in the search for new material solutions in this technology.

Polish approach to the development of AAC properties and applications

“…A technology has also been developed to produce AAC using the so‐called “new generation” fly ash from the combustion of coal in fluidized bed boilers at a temperature of about 850°C, which results in different (ash) characteristics [15, 31]. The technology was patented (patent no.…”

“…Of great importance for manufacturers is always the cost of production, which in the case of AAC is significantly influenced by the amount of binder, that is, lime and cement used. For this reason, the ongoing research into partial replacement of those binders with mineral additives with pozzolanic properties should continue [31, 37, 38].…”

“…More and more research is emerging concerning the reduction of the energy-intensive AAC components, like cement and lime. For this purpose, pozzolanic and hydraulic mineral additives, such as zeolites, geza, chalcedonite sand, expanded perlite waste and fluidized ash can be used [27,31,38]. More C-S-H can then be formed, with a C/S ratio of ∼1.0, as well as new phases like scawtite, xonotlite, girolite, and hydrogranates [42].…”

“…The AAC manufacturing process does not produce any materials or substances that could be harmful to living organisms or the environment. The subject of AAC manufacturing technology highlighting the advantages of the process has been discussed in many publications [5, 10, 15, 18, 20–22, 31, 35, 36].…”

“…AAC products are characterized by relatively high strength with low density and good thermal insulation, and thus help save energy for heating, while ensuring a healthy microclimate [5, 9, 11, 22, 31]. Modern AAC manufacturing technologies, the product characteristics and the related effects considered in the full Life‐Cycle‐Assessment (LCA) indicate that both the production process and the use of AAC fit into the requirements for sustainable development.…”