Martin Sedlmajer

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.

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 Light-Weight Concrete with Utilization of Foam Glass Based Aggregate

The use of material based on by-products and easily renewable materials in modern building structures is today’s preferred route for long-term sustainable construction and this method of construction also respects the principles of key documents, such as the Kyoto Protocol/ Paris Climate Agreements, Agenda 20-20-20, etc. In the field of light concrete (LC), the long-term effort is to effectively reduce the bulk density to a level where the concrete will still exhibit sufficient mechanical properties, so it would be possible to use it as construction material in building structure and at the same time will exhibit a sufficiently low thermal conductivity for the construction to fulfil strict requirements in the field of thermal protection of building without the need for additional thermal insulation layers. The paper describes the results of the research in the utilization of light-weight aggregate based on foam glass in conjunction with by-product based fibers for the development of light-weight porous concrete with very low density and thermal conductivity.

Effect of Plasticizing Admixtures on the Development of Hydration Temperatures and the Properties of Cement Pastes

The hydration of cement is a very intricate process. A great amount of heat is generated during the reaction, which requires close monitoring especially in large concrete members. Modified cement pastes are simpler systems and can be easily used to observe the effect of plasticizing admixtures on the development of temperatures during cement hydration as well as its rheology and mechanical properties. Knowledge of the development of hydration temperatures can be of assistance in deliberate regulation of cement hydration and the generation of hydration heat. The paper describes what influence different amounts of different plasticizers have on the properties of cement pastes, with added focus on the development of their hydration temperatures, rheology and compressive strength.

Utilization of Non-Traditional Fibers for Light Weight Concrete Production

Along with energy savings for heating and cooling, the demand for thermal insulation materials is increasing and is an attempt to achieve good thermal insulation properties for some of the construction materials. In the field of porous and lightweight concrete, this is e.g. concrete for foundations, concrete for floor constructions or flat roofs. The problem with these concrete is a relatively rapid drop in mechanical properties in reducing bulk density, with using conventional silicate binders, especially in the area below 1000 kg/m3. The paper describes the possibility of using recycled organic fibers in combination with lightweight aggregates based on foam glass for the production of porous and lightweight concrete with a good ratio of mechanical and thermal insulation properties.

Properties of Lightweight Concretes Made of Aggregate from Recycled Glass

The paper describes the basic properties of newly developed lightweight cement concrete containing lightweight aggregate based on recycled glass. The basic properties of concrete were observed, i.e. bulk density in fresh and hardened state and compressive strength. Given the low bulk density of the concretes being designed, thermal conductivity is also observed in order to assess the options off improving thermal insulation properties in a structure where such concrete may be used. Thermal insulation properties are the primary parameter in the implementation of floor or ceiling structure composition.

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.

Development of Lightweight, Remediation Plasters and Study of their Moisture Behavior

One of the strategic goals of Europe 2020 is the reduction of greenhouse gas emissions by 20 % by 2020 compared to year 1990 and increasing energy efficiency by 20 %. Closely related to the revitalization of structures necessary for reasons reduction of their unsatisfactory energy consumption and then also the construction of new building structures with minimal energy requirements by using less energy demanding materials, if is it possible from easily renewable resources. Currently, the structures involved a high degree of total energy consumption in the European Union, about 40 %. Thermal insulating plasters with using lightweight aggregate based on recycled glass are the appropriate remediation materials for the rehabilitation of existing buildings, or even for thermal insulation of new structures. In view of the fact that historic buildings are often exposed to dampness and moisture, it is necessary for these redevelopment plasters also tackle studios moisture transport. The paper describes the results of the development of new insulating plasters that would have been reflected particularly in the rehabilitation of historic buildings and problematic details of building structures.

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.

The Development of Lightweight Thermal Insulation Plasters and Experimental Analysis of their Moisture Behavior

The development of lightweight thermal insulation plasters containing alternative binders as a partial cement substitute opens the possibilities of using new, eco-friendly materials in civil engineering. The substitution of cement significantly reduces the energy consumption these materials’ manufacturing. In addition, they contribute to the overall energy performance of buildings, which represents another environmental benefit. Concerning the negative effect moisture has on the thermal insulation properties of plasters, the investigation focused on the influence of various hydrophobic agents on the hygrothermal behaviour of the newly developed porous materials. The goal of the research was to develop eco-friendly thermal insulation and rehabilitation silicate materials and to analyse their moisture transport.