Advanced Materials Research Vol. 897

Abstract: This article focuses on a special kind of polymer modified mortars (PMM) which were developed especially for industrial floorings. These floorings are designed as self-leveling screeds, repair mortars or final coatings of the floor. The article investigates systems of two different binder systems (cement and PU or EP) with polymer-cement ratios between 0,2 to 0,75 [1-. Products of this range could be called cementitious hybrids. Polymers are added into cementitious mortars for different purpose. They are used mainly to improve performance of final product like the workability, adhesion, tensile strength and many other properties of cement materials. They combine several advantages compared to conventional materials like pure epoxy or self-leveling cementitious screeds. Hybrids also show good final properties like endurance against organic and inorganic acids, high abrasion resistance, good slip resistance, toughness etc.. This kind of material can be applied on relative water-saturated substrates or a few days old concrete without cracks or blister formation. It is also known, that properly designed formulations could provide a temporary moisture barrier, which is used to minimize osmotic blister formation in polymer based top coats caused by high moisture content of the substrate. The article elaborates progress of forming co-matrix of these cementitious hybrids. These show some improved properties like waterproofness and improved adhesion to the substrate compared to the conventional cementitious mortar without an organic binder. The general advantages of using this type of material for industrial floorings are also mentioned in the article.

Abstract: This paper describes experimental investigation on the response of new advanced materials to low and high velocity load. Foams were designed using two types of porous lightweight spherical raw materials with dimensions of 30-100 μm, combined with polymer matrix. Prism shaped specimens were prepared and loaded to obtain physical-mechanical parameters bulk density, compressive and flexural strength under quasistatic load and impact strength. The load-displacement data were captured. The slab specimens were prepared of selected materials, covered with a layer of ballistic laminates on both surfaces to form the sandwich element and were subjected to the blast load of 100 g Semtex 1A from a distance of 10 cm. Blast energy absorption was measured on test rig STAND T0-B according to methodology M-T0-B VTÚO 10_09.

Abstract: The paper deals with the evaluation of epoxy adhesive modification by silane coupling agent used for gluing process of spruce wood. Moreover, the usage of primer containing the silane coupling agent was performed to find out, whether better compatibility between spruce wood and epoxy adhesive at the interface bondline can ensure sufficient resistance to delamination process. As the main criterion, tensile shear strength properties of glued specimens in different thermal and moisture exposures were carried out.

Abstract: This contribution deals with the composition of the bitumen substance of bitumen waterproofing sheets used in bridge decks in the Slovak Republic. This contribution examines the samples of waterproofing sheets from various manufacturers in terms of the bitumen areal weight and the quantity of fillers in the bitumen substance. This contribution also answers the hypothesis of whether the quantity of bitumen is increased or decreased and the filler affects the basic thermal technical properties of bitumen waterproofing sheets, such as its flexibility at low temperatures and its heat resistance.

Abstract: The aim of the article is to describe the sintering activity of industrially milled sodium potassium feldspar to determine of optimal firing temperature during fast firing typical for e.g. production of dry pressed ceramic tiles. The change of porosity, flexural strength, firing shrinkage and mineralogical composition in dependence on the firing temperature (1120 1210 °C) were determined on the test samples made from dry granulate prepared from the pure feldspar. Tested alkali sodium potassium feldspar is characterized by low sintering temperature (1190 °C) during fast firing (heating rate 10 °C/min). During the sintering process, feldspar gradually disappears in phases first of all potassium feldspar (microcline), sodium feldspar (albite) we can find in the fired body at firing temperature 1180 °C.

Abstract: There has been increased effort for achieving enhanced properties of brickwork for external cladding of buildings, in particular as regards thermal insulation. This trend is caused by various factors, while the most important one is general aiming at reduction of energetic demand of buildings (within EU connected with the Regulation of the European Parliament and of the Council 2010/31/EU) and aiming at reduction of energetic demand of production of construction materials and building structures. The price of the products themselves is also important, because it determines their competitive strength in the market. One of the ways of development of thermal insulation brickwork with enhanced end-used properties with low price and minimal demands for material resources is use of secondary raw materials with low value of thermal conductivity. The paper describes possibilities of using granulated PUR material manufactured from water PUR foam used for production of thermal insulation form-pieces with integrated insulation layer.

Abstract: In the Czech Republic, liquid glass is mainly used for painting areas with higher surface temperatures, such as bonding agent of heat-resistant concretes, which require higher chemical resistance; it is also used as additional damp proofing for buildings with damp brickwork. Globally, liquid glass is used with expanded perlite as thermal insulation for higher temperature (maximum application temperature of 650 °C). This paper should outline the possible preparation of such material in our conditions and verify, whether it is possible to achieve the bulk density for such material of up to 200 kg/m³, or the potential application of such material.

Abstract: Silica is used for lining of the upper parts of glass furnaces and their regenerators and for lining of the lids of arc furnaces and for the coke oven batteries construction. Silica bricks represent 60% of refractory material used for a coke battery construction. Coke ovens are generally the largest oven aggregates, where silica material is used. The whole coke oven battery may reach the length up to 80 m due to the chamber sizes. A single coke oven battery contains up to 50.000 tons of refractories [1]. From the material science point of view, the durability of silica bricks depends on numerous parameters including first of all porosity and mineral composition. Microstructure of silica bricks changes during their application due to the heat load, repeated heating and cooling, and direct contact with the oven atmosphere. The paper discusses the possibility of reducing the apparent porosity and increasing of bulk density of coke oven silica bricks. It describes the effects of an iron dust, microsilica and influence of the compaction pressure on the coke oven silica microstructure. Functional characteristics of the material prepared according to the new standard recipes are compared with the properties of standard silica products.

Abstract: This work deals with oportunity of recycled glass utilization as pozzolanic aktive substance. It analyzes pozzolanic dependency on reached specigic surface and method of grinding in various types of mills. This way arisen admixture is researched in mineralogical and technical aspekt.

Abstract: NDT method of impedance spectroscopy was used to characterize concrete slab specimens without and with contact graphite compound coating. Differences in tanδ(f), ImZ(f) and ReZ(f) spectra for dry specimens were observed. Furthermore, based on the predominant loss type, the material quality was characterized. Our measurements confirmed the reproducibility of this method. Furthermore, the influence of the concrete specimen composition on their electric parameters was assessed.