The influence of regranulate admixture on the properties of wood-polymer composite

Matrice dřevoplastového kompozitu je tvořena termoplasty s nízkým bodem měknutí, nejčastěji polyolefiny nebo polyvinylchloridem. Tyto termoplasty s širokým průmyslovým využitím umožňují jednostupňovou recyklaci, která by měla zachovat požadované vlastnosti primárního polymeru. Využití recyklované drtě nebo regranulátu pro výrobu dřevoplastového kompozitu závisí tedy na splnění parametrů (druhotné) suroviny v souvislosti s účelem a technologií výroby produktu.The WPC matrix is made of thermoplastics characterized by low softening point. The main types of WPC matrixes are polyolefins and polyvinylchloride. These thermoplastics, which provide a broad range of industrial utilization, allow a single-stage recycling that should maintain the virgin polymer properties. Therefore, the use of plastic regranulates in the form of a WPC matrix depends mainly on whether they meet the parameters required by the use purpose and production technology

Synthesis of Tobermorite Structure with Non-traditional Silica Components

The main aim of the article is research of kinetics of creation of calcium silicate hydrate (CSH) and calcium aluminate hydrate (CAH) phases in the autoclaved aerated concrete in dependence on type of raw materials. Regarding materials, this will be unique combinations of lime with fly ash, quartz sand or silica fume. The aim will be to prove the influence of ratio of individual types of materials on the CSH phase to determine optimal combinations of raw materials. The research focuses first on detailed analysis of the used materials. Next focus is kinetics of the creation of microstructures of silicate phases under ideal conditions of small-sized autoclave reactors (250 ml, 190 °C, 1.3 MPa). The produced samples are further analysed using of x-ray diffraction (XRD) and scanning electron microscopy (SEM) for qualitative valuation of created microcrystalline phases. The results show that the most suitable non-traditional silica component is ash from coal combustion. The optimal combination of amorphous and crystalline silicon in combination with Al2O3 provided the highest proportion of synthesized tobermorite even in more economical autoclaving variants

The Use of Secondary Crystallization in Cement-Based Composites

The paper focuses on the study of the properties of cement-based composites produced using secondary crystallization (crystalline additive). In this study, cement mortar made with secondary crystallization was exposed to an aggressive environment and the influence of secondary crystallization on the degradation of the cementitious composite was investigated. The results indicate that the crystalline additive contributed to increasing the resistance of the cement-based composite to the attack of the selected environments (sodium sulphate solution and ammonium chloride solution)

OPTIMIZATION OF MIX-DESIGN OF CHEMICALLY RESISTANT SPRAYED CONCRETE

This paper addresses optimization of mix-design and granulometric curves of aggregate of chemically resistant cementitious sprayed mix. The target of the paper is to improve properties of currently developed mix-design, which has no chemical resistance, and to utilize the secondary raw materials. The mix was optimized by additions improving chemical resistance and binder substituted by secondary raw materials. The binder was substituted by finely ground waste glass and high-temperature fly ash. Filler was substituted with slag from deposit yard and waste sand with soluble glass from steel manufacture. Main observed properties for design of optimized mix were workability time, consistence and physical-mechanical properties. Optimized mix-design successfully replaced all fine parts of filler and up to 30% of binder while the physical-mechanical properties were preserved or even enhanced. Optimized mix-designs show the same consistencies and workability times

New Evaluation Methodology for Solidification Product Durability Assessment

This paper deals with a proposal of a new methodology for durability assessment of solidification product for its safe further use. The new methodology is based on a review of the current state of assessment of treated waste in Czech Republic and abroad. The aim of the paper is to propose an optimal evaluation methodology for verifying properties of solidification product to ensure its safe further use in building industry

Study of Possibilities of Using Special Types of Building and Demolition Waste in Civil Engineering

Construction and demolition waste makes up a substantial part of all waste produced in Europe. Its impact on the environment may be relatively small, but it exists in large amounts and holds many options of re-use. This is why it remains a frequently discussed topic of European policy. As part of circular economy, the European Commission has already proposed new goals and strategies for existing types of waste. However, they are not entirely clear on the usage of new kinds of building and demolition waste, as they are yet to be specified by existing legislation. This paper discusses new kinds of building and demolition waste and the basic principles (new technology) of their use. The possibilities of utilizing new kinds of waste are based on a multicriteria optimization calculation, specifying each material and proposing ways of its further use. Recent findings can expand the choice of new uses of construction and demolition waste and reduce their impact on the environment (less waste, better properties and more effective processing, reducing transportation needs, maximizing re-use and recycling)

What if houses were powered by milk?

© 2017 Elsevier B.V. Living architectures and green energy are hot topics of the applied sciences. They aim to develop buildings that co-live with their environment and co-habit with people they house. An ultimate goal would be to make every block in a building capable of producing energy. We present results of scoping, and somewhat illustrative, experiments on generating electrical energy in modified aerated concrete blocks. These blocks are commonly used in modern building industry and therefore make an ideal candidate for ‘inbuilt’ microbial bio-reactors. We fill the blocks with milk to evaluate electro-generation potential of a pasteurised milk and to study power generating potential of the medium nutrient rich for micro-organisms. We assess the practicality of using bio-reactors which become colonised by local micro-flora