Advanced Materials Research Vol. 1124

Abstract: Throughout history, natural fibres have been known to be added in plaster mixes in order in order to prevent the formation of microcracks. These plasters can still be encountered during reconstruction of historical buildings but are used in new buildings as well. The goal of this research was to develop new, low energy cost thermal insulation plasters with natural fibres and afterwards examine and analyse their hygrothermal transport. Given their presumable application in the rehabilitation of old and historical buildings which often suffer from damp and salt attack, the research was also focused on the examination of their capillary activity.

Abstract: Structure and properties of cement composite are time-varying characteristics, depending among others on environmental conditions. The key idea of the project is a struggle for complex research of joint effect of physical, chemical and dynamic loads on the internal structure [8] of cement composite and understanding the correlation between changes in microstructure and macro-scale properties [5]. During the experimental program, specimens will be exposed to combined influence of freeze-thaw cycles [9], aggressive chemical agents and dynamic loading [7]. The aim is to create a theoretical basis for design of effective cement composites meant to be used in severe environmental conditions. Results of first dynamic load tests carried out on prismatic specimens (100x100x400 mm) are presented in this paper. The results are supplemented by ultrasonic measurement.

Abstract: This study deals with stability and quality of surface treatment of concrete roof tiles, considering the use of special inorganic binders spraying onto freshly prefabricated surface of concrete roof tiles. Their application leads to smoothing of surface defects generated from previous processing. Method of applying the coating is discussed in this work among with stability study of styrene-acrylate cement mixtures. Impact of presence of selected styrene-acrylate copolymer onto the hydration of cement is evaluated, in order to verify, for how long could be prepared mixture used for treating freshly fabricated surface of concrete roof tiles. Pull-off tests results after freeze-thaw test are further presented in this study to verify designed coating process properties.

Abstract: The paper is about a research focused on a development of thin slabs made from white UHPC. These slabs are reinforced by scattered PVA fibres and textile glass reinforcement in form of 2D net. The aim of the experiment is the development of tin slabs that can be used as facade or roof panels. The course of the experimental tests of these slabs and its correspondence with the numeric analysis made with ATHENA software is in the paper. Three slab specimens with size of 750 x 125 x 15 mm were tested in four-point bending. The white UHPC matrix was reinforced by the scattered PVA fibres and the 2D textile glass reinforcement with mesh 20 x 20 mm. The used 2D reinforcement was coated against alkali conditions, so called AR - Glass with 2400 TEX fineness. The reinforcement was placed and fixed near the lower surface of the slabs. The course of the tests was continually monitored by an automatic measuring unit where especially the acting force, the deformation in the middle of the span, the deformation in the supports and the progressive formation and development of cracks were detected. The numeric model was created in 3D surroundings of Gid 2011 program and then converted into ATENA software.

Abstract: The paper is focused on the use of advanced composite materials in the real application areas of buildings exposed to extreme environmental stress. The paper describe properties of composite rebar, especially with regards to long-term resistance to chemical and corrosion attack, minimization of heat transfer or resistance in construction with reduced concrete cover. The paper also presents behavior of composite rebar and concrete samples with composite reinforcement during loading and fire tests.

Abstract: Natural fibre based thermal insulating materials belong to progressive building materials representing one of the possible ways in sustainable development and which are characterised with low carbon trace and low value of primary bound energy. In case of industrially produced insulating materials (for instance using thermal connection method) the insulating materials based on natural fibres showed comparable properties with industrially produced insulating materials on building markets. In the view of thermal insulating properties the natural insulating material show slightly different behavior in comparison with synthetic insulating materials which is caused by fibrous structure of insulating materials and low thermal conductivity of natural fibres (contrary to glass or mineral fibres). The paper describes results of research oriented on study of heat propagation within materials based on natural fibres originated from agriculture and stockbreeding.

Abstract: The present study deals with ballistic performance of corundum and silicon carbide ceramics against 7.62 mm calibre projectile. In particular, ceramic samples of dimension 100 x 100 mm with various thickness in the range of 6.94 – 6.96 mm and 7.77 - 7.79 mm were glued to Al plate with thickness of 8 mm and tested against 7.62 mm calibre projectiles, namely 30.06 M2 AP, 7.62 mm x 51 AP (WC) and 7.62 mm x 54 R B32. The conducted tests have provided the V₅₀ value for tested materials composed of 8 mm Al plate and ceramic.Furthermore, applying linear approximation the value V₅₀ for normalized ceramic areal density of 26 kg/m² was calculated. From the given V₅₀ values, the energy of projectile absorbed in ceramic and in Al plate was also calculated. Finally, the results showed that corundum ceramic exhibited significantly lower ballistic efficiency probably due to lower thickness (26 kg/m² corresponds to thickness of 6.61 mm) in comparison with SSiC ceramic (26 kg/m² corresponds to thickness of 8.33 mm). The highest efficiency showed 7.62 mm x 51 AP (WC) with a hard core against both ceramics. An unexplained point remains similar V₅₀ value for 30.06 M2 AP and 7.62 mm x 54 R B32 projectile for corundum ceramic and significantly different for SSiC ceramic.Graphical abstract

Abstract: The paper deals with the development options of particular insulation based on a blend of recycled cellulose fibers and natural (mainly) bast fibers. The paper presents the results of research work in the field of addiction thermal insulation, acoustic and mechanical properties of experimentally produced insulators on density..Keywords: Natural fibers, thermal conductivity, insulation materials, straw, fibreboard, cellulose fibers

Abstract: The article is focused on complex analysis of the principles of degradation of composites based on alkali-activated materials exposed to extreme temperatures (max. temperature 1200 degree of Celsius). Thanks to specific properties these materials show a remarkable potential for the special application, for example for construction with high risk of fire etc. The effect of high temperatures shall be tested not only at such extreme levels but also at gradually increasing temperatures. The temperature effects shall be evaluated not only in of changes physic-mechanical parameters but also the physic-chemical determinations.

Abstract: Paper deals with development of face architectural fibre-cement composites based on white Portland cement with addition of photoactive TiO₂. Tests were carried on composite binder and then on the composites. The role of TiO₂ on performance of materials was monitored. Selected composites were tested on self-cleaning ability, de-NO_x activity and resistance to weathering in outdoor conditions. Two series of thin-walled products based on developed composites were prepared with self-cleaning ability and de-NO_x activity.