Research of the use of waste rigid polyurethane foam in the segment of lightweight concretes

Abstract

The question of the reduction of waste production and the method of safe, environmentally acceptable and economically profitable use or disposal of waste has currently been a very widely discussed global issue from the point of view of the environment. According to data from the statistics of the largest companies in the world and the only global non-governmental organization dealing with the management of secondary raw materials, the Bureau of International Recycling based in Brussels, it is clear that the industry of secondary raw materials uses 700-800 million tons of secondary raw materials a year, which is more than 40% of all the materials used in industry. This article addresses the issue of the use of waste rigid polyurethane foam after the end of its life cycle with a density of 30 to 40 kg.m-3 as a new filler in the segment of lightweight concretes.

The introduction part of this article informs about the current state of the use of secondary raw materials, and it is focused on the incorporation of waste products in the building industry. It presents the results of research and development concerning the use of plastic, rubber and metallurgical waste materials in building industry and a general treatment of these waste materials for their further use. The article describes the individual materials used to prepare the experimental concrete mixtures and the methods used during the research. The experimental part evaluates the particle-size analysis of the input crushed polyurethane foam and selects a suitable type for subsequent incorporation into the concrete mixture. It is a new type of filler, which replaces the natural filler in the amount of 100%. It also presents the individual designed experimental formulas of concrete mixtures based on polyurethane and the test results of their physical and mechanical properties. The tests performed on the experimental mixtures included slump, density of fresh concrete mixture and compressive strength tests. The test results have shown that crushed rigid polyurethane foam can be used as the filler in lightweight concretes, and this new type of lightweight concretes can be produced with different densities, depending on the different ratios of the added components. The conclusion of this article confirms the possibility of using rigid polyurethane foam in building industry as a secondary raw material, representing a possible solution of the disposal of these waste materials.