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Dziuk D.,Silesian University of Technology | Giergiczny Z.,Wydzial Budownictwa Politechniki Slaskiej | Garbacik A.,Instytut Ceramiki i Materialow Budowlanych
Road and Bridges - Drogi i Mosty | Year: 2013

The results of tests concerning properties of cements containing calcareous fly ash obtained by a process of lignite combustion are presented in the paper. The scope ofthe study includes: Portland fly-ash cements CEM II/A,B-W; Portland composite cements CEM II/B-M containing a mixture of calcareous fly ash (W) and granulated blast furnace slag (S), siliceous fly ash (V) or limestone (LL), as well as pozzolanic cements CEM IV/B-W and CEM IV/A,B (V-W). Standard properties of cements, including cement water demand, mortars consistency and mechanical properties, are described in the paper. The obtained results have proven that use of calcareous fly ash in the production of common cements, especially Portland composite cement CEM II/B-M, is possible. Cements containing calcareous fly ash, regarding setting time, soundness and compressive strength, exhibit similar properties to the ones of cements with additives (CEM II - CEM V), available on the market for a long time. The use of calcareous fly ash in greater amount in cement composition (above 20%) results in the increased water demand and deterioration of mortars rheological properties. The process of intergrinding of fly ash with clinker in cement production results in decreased negative impact on cement water demand. Source

The paper presents the experimental results of the methylcelulose effect on the hydration of the mixture of alite and tricalcium aluminate, also with gypsum addition. The experiments have shown that the methylcellulose admixture is hampering the hydration of alite, and the peaks of portlandite on the XRD pattern are appearing only after 24 hours. Even after 168 hours their intensity is lower than in the sample without this admixture, which is relating also to the reaction of C3A with water. In the case of gypsum addition to the mixture of alite with C3A the influence of methylcellulose is much lower, however, also well marked. The gypsum addition is accelerating alite hydration in the mixture with C3A, in both cases: with and without metylcelulose admixture. © 2014, Foundation Cement, Lime, Concrete. All rights reserved. Source

Naziemiec Z.,Instytut Ceramiki i Materialow Budowlanych
Prace Naukowe Instytutu Gornictwa Politechniki Wroclawskiej | Year: 2012

Industrial comminution is the most energy consuming operation in the aggregate production sector. Several factors, including the feed and products properties, type of applied device, and the technological process run, have an effect on the level of the process energy-consumption. The relationships between the feed and final product characteristics and the energy consumption of various crushing devices were presented in the paper. An influence of selected process parameters on the level of energy consumption was analyzed in the light of the most common comminution theories, the results of pilot plant scale energy consumption results were also presented. Main directions of development of crushing devices, applied in the sector of fillers and coarse aggregate production, were indicated in the article. Source

Pichniarczyk P.,Instytut Ceramiki i Materialow Budowlanych
Cement, Wapno, Beton | Year: 2013

The effect of gypsum and two kinds of methylcellulose with plastic viscosity of 40 and 70 Pa·s on alite hydration was studied. The results have shown that gypsum retard alite reaction with water and this effect is significant till 24 hours. After 168 hours the heat of reaction is higher for alite sample with gypsum addition. The retarding effect of methylcellulose is significant in the sample of alite without gypsum. The influence of plastic viscosity i.e. 40 and 70 Pa·s of this admixture is insignificant. In the sample with gypsum addition the retarding effect is much lower. Source

Agency: Cordis | Branch: FP7 | Program: BSG-SME-AG | Phase: SME-2012-2 | Award Amount: 1.62M | Year: 2013

Refractories are materials essential for all highly industrialised processes which are performed at elevated temperatures e. g. iron- and steelmaking, cement production, glass, ceramics, nonferrous metals, power production and waste incineration Refractories have high economical importance and serve a key function for the industry in Europe. In Europe, most of refractory manufactur are SMEs. The technical suitability of refractory products is warranted through physical, chemical and technological materials properties, laid down in data sheets. For the purpose of obtaining those technical specifications, testing methods are described in national and international standardisation systems, like DIN, CEN or ISO. Progressively, the established standard testing methods no longer fulfil the increasing requirements of the refractory market. This project is a response to the need for a systematic investigation of the accuracy, precision and reproducibility of the current EN testing standards for refractories with the aim to enhance their relevance, especially to the specific needs of SMEs. The central objective of this project is to increase the competitiveness of the European SME refractory producers. This will be archived by generating up-to-date EN testing standards as a save guidance for the producers. An extensive investigation of the current EN testing methods, designs of experiments and interlaboratory tests, more specifically collaborative tests, involving the major European refractory testing laboratories will be the key approach to attain this objective. For a successful review of the EN testing standards and an effective dissemination of the results, a strong and broad-based cooperation between transnational partners is planned. For this purpose, the European SME-AG for the refractory industry is involved and brings together the most active European testing laboratories and SMEs to conduct a large scale and in-depth study of EN testing standards.

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