Abstract. The paper presents the results of the research on modifications of silicate bricks with a polypropylene mesh and their influence on physical, mechanical and microstructural properties of such bricks. The main goal of the paper was to determine effects of the polypropylene mesh on sand-lime product parameters. The analysis has focused on compressive strength, water absorption, bulk density and structural features of the material. The obtained product is characterized by improved basic performance characteristics compared to traditional silicate products. Using the polypropylene mesh increased compressive strength by 25% while decreasing the product density. The modified products retain their form and do not disintegrate after losing their bearing capacity.
IntroductionStatistics on production and application of building materials in Poland, and in the world, show that consumption and demand for silicate materials have increased since the turn of the 21st century. They are not only used in Eastern and Central Europe, but also in Germany, Portugal, and the Middle East and Asian countries [1]. Such autoclaved bricks have the strength of 15-25 MPa, and are designed for constructing structural and partition walls (depending on a type), including up to 5 storeys, and in justified cases more. Civilization and technological advances force modifications in all industries, including a construction industry. By studying each type of material, its properties i.e. strength, density, water absorption and thermal properties are a priority. Such performance characteristics are due to bonds and reactions resulting from a hydration process between a binder and water. Autoclaving (hydrothermal treatment), in the case of silicate bricks, accelerates material maturation, the result of which is an artificial stone (mortar) as the end product.Crystalline phases produced in a sand-lime product depend on the whole brick production process, including mainly autoclave conditions, temperature, steam pressure, quality and proportion of constituents used, aggregate fractions and others [2,3].A modification of sand-lime product composition is a decisive factor in the technology development and leads to structural changes and performance of a product. Using basalt aggregate [4], barium sulphate [5,6], lithium silicate [7] or leachate from a landfill [8] has improved properties of sand-lime products. Efforts were also made to reduce bulk density of silicates and improve their thermal insulation properties by using a light additive in the form of expanded glass granules [9,10].In the era of sustainable development, attempts have been made to dispose of waste materials by using them as a filler in silicate products. Modifying sand-lime bricks with plastics (high impact polystyrene HIPS, and polypropylene and polyethylene PP) in the form of regranulates has improved strength, while lowering absorbability and density of finished products [11,12]. Using granular
