Jitka Peterková

Utilization of Lightweight Aggregate from Expanded Obsidian for Advanced Thermal Insulating Plasters Production

The thermal insulating of new and existing buildings is of a key influence in reduction of their energetic demand factor resulting in reduction of emissions of gases, carbon particles and dust which directly improves the environment. At development of light thermal insulation plasters with very low thermal conductivity the foam-plastic matters or light porous aggregates are frequently used at present. The foam-plastic materials do not appear as convenient ones in view of the environment and sustainable development as well. In the given case the thermal insulation plasters based on light cellular aggregates appear as more suitable. However a majority of light aggregates (for example expanded perlite) do not show a good ratio of insulation and mechanical properties. The paper describes a design and development of thermal insulation plasters based on expanded obsidian that can be used for thermal insulating of building constructions and for moisture sanitation. Considering the applied type of aggregates the materials show better ratio of thermal insulation and mechanical properties while in practice the plasters can be used as a full- value alternative for classical thermal insulation systems.

Investigation of Thermal Insulation Materials Based on Easy Renewable Row Materials from Agriculture

Production of building materials is mostly energy consuming. In the sphere of insulation materials we mostly see rock wool based materials or foam-plastic materials whose production process is demanding from material aspect and raw materials aspect as well. At present the demand for thermal insulation materials has been growing globally. The thermal insulation materials form integral part of all constructions in civil engineering. The materials mainly fulfill the thermal insulating functions and also the sound-insulating one. The majority of thermal insulation materials are able to fulfill both of the functions simultaneously. The paper describes questions of thermal insulation materials development with good sound properties based on natural fibres that represent a quickly renewable source of raw materials coming from agriculture. The main advantage of the materials are mainly the local availability and simple renewability of the raw materials. In addition an easy recycling of the materials after their service life end in the building construction and last but not least also the connection of human friendly properties of organic materials with advanced product manufacture qualities of modern insulation materials.

Development of Masonry Components Protected against Moisture

During construction process and life, a number of negative influences can have effect on masonry structures; moisture, which is undesirable in the masonry, can be one of such influences. The lower area of the masonry (plinth walling) is strained the most by the moisture. The paper deals with potential reduction of the effect of moisture in places, where the masonry structure is founded, through hydrophobization of walling units. Such solution of the issue of protection of the building structure against the influence of humidity should not have negative effect on the resulting masonry parameters, particularly not on the potential application of surface treatment materials. The collective influence of the surface treatment materials, consisting usually of plaster, and the actual masonry should be ensured.

Development of New Advanced Plasters with Waste Fibers Content

The paper deals with the possibilities of using secondary raw materials in the development of new advanced lightweight plasters. It was about fibers from recycled waste materials (waste paper, PET bottles, tyres) and recycled insulation (stone wool). The aim of adding fibers to these lightweight building materials was improvement of mechanical properties, improvement thermal insulation properties and reduction of crack sensitivity. It can be stated, based on the evaluation of the selected measurements, that both types of cellulose fibers and fibers from recycled tyres had positive influence on the mechanical properties, namely in the case of compressive strength. From the point of view of thermal insulating properties, it can be said that only 2 types of fibers have reduced the value of the thermal conductivity. They were mixtures with stone fibers and with recycled tyres fibers. Both of these mixtures also showed the lowest average values of bulk density. Based on the carried out research works can be it concluded that the use of recycled tyres fibers show as optimal.

Computational Simulation of Behaviour of Developed Thermal Insulation Plaster Based on Silicates with the Use of Program WUFI 2D

The investigation of the hygrothermal behavior of advanced silica materials, which are today in ever increasing demand during the reconstruction of building envelopes, is an important point of research. For determining the moisture balance in building structures, the Glaser method is most frequently used to day which, however, considers during calculations water diffusion only in stationary state at simplified marginal conditions; it does not take into account the moisture transport in the capillary system of the material structure, nor the sorption properties of the material. The goal of the research is therefore to gain deeper knowledge of the way heat and moisture transport through the pore structure of these silica materials. The paper describes verification of efficacy of thermal insulation and rehabilitation silicate plastering. Based on experiences from previously research and their results were chosen 2 developed plasters for computational simulation of their behavior in the case of detail of window jamb. One type of developed plastering was placed from the site of interior and the second type of plastering was applied from the site of exterior.

Effect of Used Binders in Lightweight Plaster Mixtures on their Thermal Insulation Properties

Good thermal insulation properties of the surface structures lead to reduction of heat losses in buildings. This reduces the energy required for heating which is positive fact from the view protection of the environment. The aim of the research intent, which is going at Faculty of Civil Engineering in Brno, is the development of high-quality, thermal insulating plasters using both conventional binders, and alternative binders, whose acquisition-production is in comparison with the technology production of cement less energy intensive. Due to the fact that increasing moisture leads to deterioration of the thermal insulating properties, further research works were devoted to the study of the influence of relative humidity and moisture content on the thermal insulation properties of lightweight plasters, including of the determination of capillary absorption coefficient. This paper describes evaluation of the development of insulating plasters based on lightweight aggregates, using different ratio of cement and lime hydrate and other chemical additives. There are presented results of the study of basic physical and thermal insulating properties, including the study of sorption properties developed lightweight plaster mixtures.

Dispersed Reinforcement Based on Natural Fibres Used in Cement Composites

One of the options for improving the mechanical properties of cement composites is the use of fibre reinforcement. Nowadays, steel or polymer fibres are most frequently used for this purpose. However, given the increasingly stricter requirements related to environmental protection, one goal is to find ways of using alternative fibres of natural origin or waste fibres for which it is difficult to find other practical use. This paper focuses on one part of the development of materials which contain natural waste fibres as dispersed reinforcement in thermally insulating cement composites. The authors aimed to observe what influence the fibres have on the material’s final mechanical properties as well as thermal insulation properties. Another important factor, which was investigated, was the quotient of mechanical and thermal insulation properties. The results of this research showed that waste cellulose fibres have a considerable effect. The best compressive strength values were found in mixture M-2-BF which contained waste basalt fibres. The highest flexural strength values were reached by mixture M-3-CF-a containing cellulose fibres.

Study of the Properties of the Environmentally Friendly Insulation Materials

Increasing demand for new progressive construction materials requires development of modern environmentally friendly materials with excellent end-use properties and reasonable price. One of the main objectives of material research in building industry is using renewable resources of raw materials of industrial waste for development of new construction materials. Current trend of thermal insulation of building constructions results in development of environmentally friendly insulation materials based on renewable material resources from agriculture and stock farming, which could became alternative for current common use insulation materials in the future. Paper describes results of research and development of materials based on natural fibres.

Possibilities of Hydrophobization of Thermo-Insulating Materials Based on Natural Resources

Current times emphasize utilization of new and promising building materials with no negative environmental impact, for reasonable price and with excellent end-use properties. Insulation materials based on natural fibers represent a good alternative for current standardly used insulation materials like foamed plastic materials and mineral wool. Input materials for such industrial insulation materials are particularly crude oil and non-renewable natural resources (moreover, manufacture of these insulation materials consumes high amount of energy). From this point of view, natural insulation materials are more advantageous, because their manufacture uses easily renewable materials resources, like fibers from agriculture (flax, technical hemp). However, these materials have two disadvantages higher sensitivity to humidity (higher water absorbing capacity and hygroscopic nature) and worse reaction to fire. The paper deals with selection of appropriate hydrophobic agent preventing high sensitivity to humidity of developed natural materials and monitoring of moisture content after application of hydrophobized materials within the frame of the ETICS system.

Hygrothermal Behavior of Thermal Insulating Material Based on Technical Hemp and its Application in Construction

Natural insulation materials have great potential of development given the contemporary requirements of the society in terms of reducing the energy demands of the production of building materials and the reduction of CO2 emissions. Natural fibers are characteristic by their high moisture absorption and combustibility. The paper describes the results of research in the field of heat and moisture transfer within the structure of insulating materials based on natural fibers (hemp). The results of the experiments provided input data for computational simulations of hygrothermal behavior of hemp based fiber insulation applied in building envelopes.