Search

The benefit of recycling industrial by-products in the construction industry led to growing interest in exploring and potentially exploiting these by-products, in the context of sustainable development, and in creating new materials. Fly ash is a type of byproduct waste, having enjoyed considerable attention, especially from the perspective of creating and perfecting fly ash based geopolymer concrete. In Romania, over 80% of industrial waste is deposited, this being the most widely used method of waste disposal. This creates the premises of potentially using this waste as a source material in producing fly ash based geopolymer concrete. In order to obtain a material with desirable compressive strength, the mix design of geopolymers needs to be carefully studied and much research remains to be conducted. The aim of this paper is to present the preliminary results for producing fly ash-based geopolymer paste, using Romanian local source materials and to open new perspectives on the global existing research agenda about the production of fly ash-based geopolymer concrete. Preliminary results shown a compressive strength of the fly ash-based geopolymer paste between 7 and 25 MPa, at 2, and 7 days, respectively when keeping the fly ash/alkaline liquid ratio constant and different Na2SiO3 solution/NaOH solution ratios, with NaOH solution concentration of 8M. [ABSTRACT FROM AUTHOR]

Sustainability is a criterion defined since the 1980s, essential in all areas of activity, without which development cannot be acheived. Thermal insulation mattresses produced using sheep wool, successfully meet the conditions imposed by this criterion. This type of building material ensures the responsible use of non-renewable natural resources, the possibility of reuse and recycling of materials, contributes to environmental protection and pollution reduction, energy saving and provides a hygienic and healthy living climate. This paper analyzes how sheep wool mattresses meet sustainability requirements, simultaneously with compliance with specific requirements in construction based on the criteria of regulation (EU) no. 305/2011 of the European Parliament and of the Council of 9 March 2011 laying down harmonised conditions for the marketing of construction products. At the same time, the physical and mechanical performances of 20 types of sheep wool mattresses, from 7 manufacturers, available on the international market, are presented. This identifies the strengths of these products (thermal insulation performance, low overload of the structural strength of buildings due to low density, low environmental impact and contribution to improving indoor air quality), as well as weaknesses (high water absorption, low mechanical strength, which make it difficult to use outside buildings, requiring either indoor location, additional protection measures for outdoor location). However, cumulating all these aspects, it can be said that sheep wool mattresses are a good heat-insulating material, which successfully meets the requirements of sustainable development, the benefits in terms of environmental impact and quality of life recommending them as a possible substitute for some sintering heat-insulating materials, highly polluting and hardly or not at all biodegradable. [ABSTRACT FROM AUTHOR]