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Jozwiak-Niedzwiedzka D.,Instytut Podstawowych Problemow Techniki PAN | Gibas K.,Instytut Podstawowych Problemow Techniki PAN | Glinicki M.A.,Instytut Podstawowych Problemow Techniki PAN | Nowowiejski G.,Instytut Podstawowych Problemow Techniki PAN
Drogi i Mosty | Year: 2011

The subject of the investigation was evaluation of the permeability of concrete made with high calcium fly ash (HCFA) from brown coal combustion. Raw (unprocessed) and additionally grinded HCFA was tested. The influence of HCFA type and content on the concrete resistance against penetration of aggressive fluids and gases was studied. HCFA was used for partial replacement of cement in concrete mix assuming the efficiency factor k [1] 0.4. The chlorid emigration coefficient in non-steady diffusion state, the water- and air-permeability as well as t hecompressive strength of concrete were measured. The evaluation of microstructure of concrete was performed using SEM and optical microscopy in transmitted light on thin sections. It was been found that partial replacement of Portland cement by HCFA (15% or 30%) with water to binder ratio w/b=0.55 increased the resistance of concrete against water and air ingress. The grinding process of HCFA improved the air-impermeability of concrete. For w/b=0.45 the influence of HCFA on the water permeability of concrete was unnoticeable. A significant influence of partial replacement of cement by HCFA on the chloride resistance of concrete was found. The lowest value of the coefficient of chloride migration was obtained for concrete made with HCFA, for higher values of w/b the penetration of the chloride ions increased. Image analysis performed on thin sections revealed an increased content of unburned carbon particles in the matrix for higher HCFA content in concrete. The size of unburned particles was inversely related to the grinding time of HCFA and this could influence the permeability of concrete.


Knor G.,Instytut Podstawowych Problemow Techniki PAN | Glinicki M.,Instytut Podstawowych Problemow Techniki PAN | Holnicki-Szulc J.,Instytut Podstawowych Problemow Techniki PAN | Ossowski A.,Instytut Podstawowych Problemow Techniki PAN | Ranachowski Z.,Instytut Podstawowych Problemow Techniki PAN
Road and Bridges - Drogi i Mosty | Year: 2013

As a measure to avoid thermally induced cracking in massive concrete, mineral admixtures are often added as a substitute for a certain portion of cement. This paper presents the results of testing in course of which the temperature was measured during hardening of concrete mixtures produced with addition of calcareous fly ash obtained from the Power Station in Bełchatów, Poland. The investigation covered 76 concrete mixtures produced with three different aggregates and diverse binder content. In the experimental part of the research, the thermal parameters of hardening concrete were determined with a specially developed method in which the mixture was placed in a one-dimensional mould which allowed for unrestrained flow of heat in one direction. The results of testing were used to assess the influence of the respective ingredients, in particular calcareous fly ash, on the rate of rise of the fresh concrete temperature, on the time of occurrence of the maximum temperature and on the temperature gradients. Finally, a formula for calculating the specific heat of hydration depending on the mixture composition was proposed.


Dabrowski M.,Instytut Podstawowych Problemow Techniki PAN | Glinicki M.,Instytut Podstawowych Problemow Techniki PAN
Road and Bridges - Drogi i Mosty | Year: 2013

The paper presents results of the investigation of the air void characteristics and the resistance to cyclic freezing and thawing of air-entrained concrete containing calcareous fly ash. The frost resistance was tested also under the presence of de-icing salts to check the resistance to frost-salt scaling and without de-icing salts. The range of investigation included air entrained concrete mixes with the specified water-binder ratio of w/b=0.45 with addition of calcareous fly ash or made using blended cements with calcareous fly ash (W), and also siliceous fly ash (V) and ground granulated blast-furnace slag (S). The coarse aggregates used were crushed granodiorite and crushed limestone. The air-void system parameters were determined by microscopic image analysis and the effect of addition of calcareous fly ash was assessed. The effect of concrete age and presence of fly ash W on the strength and freeze-thaw resistance was also studied. The tests have shown that the use of calcareous fly ash as one of the main constituents of blended cements does not affect the frost salt scaling resistance nor the resistance to internal frost damage provided that the air void system is adequate.


Glinicki M.A.,Instytut Podstawowych Problemow Techniki PAN
Cement, Wapno, Beton | Year: 2014

In the paper the qualitative and quantitative methods of concrete air entrainment were presented, not only these which are in standard, but also behind them. From the last ones the foam index, foam stability and the method applying buoyancy rule of particles migration were described and their drawbacks as well as the good points are given. Detailed discussion is devoted to microscopic method of pores structure determination and the drawback of standard lack is underlined. Also the Danish, German and Canadian Standard are discussed, the last one especially in the case of roads construction. © 2014, Foundation Cement, Lime, Concrete. All rights reserved.


Moranda H.,Poznan University of Technology | Ranachowski P.,Instytut Podstawowych Problemow Techniki PAN | Moscicka-Grzesiak H.,Poznan University of Technology
Przeglad Elektrotechniczny | Year: 2010

The article describes results of the attempt to find out the correlation between porosity of porcelain and selected parameters describing partial discharges generated under AC voltage. The study shows that there is a correlation between the percentage of different sizes pores and the frequency of PD pulse occurrence.


Zurek Z.H.,Silesian University of Technology | Kukla D.,Instytut Podstawowych Problemow Techniki PAN | Kurzydlowski K.J.,Warsaw University of Technology
Przeglad Elektrotechniczny | Year: 2012

The fatigue degradation of ferromagnetic steels proceeds with the changes of electrical (γ) and/or magnetic (μ) parameters. The article presents some selected issues of research into correlations between the magnetic parameters and the material fatigue degree, in operating conditions as well as quantitatively controlled in laboratory conditions. In order to identify and assess the effects of fatigue, a methodology of quantitative description of material defect degree was developed. According to the developed methodology, a set of standard samples with specified value of their defect degree was prepared. There were tested and analyzed the microstructural aspects of degradation process taking place in the operating conditions under the influence of variable mechanical, thermal and environmental loads, and also in the conditions of single-variable loads performed in the laboratory.


Beblacz D.,Instytut Badawczy Drog i Mostow | Glinicki M.A.,Instytut Podstawowych Problemow Techniki PAN | Sobczak M.,Instytut Podstawowych Problemow Techniki PAN | Wolowicz J.,Instytut Podstawowych Problemow Techniki PAN
Road and Bridges - Drogi i Mosty | Year: 2012

Concrete manhole covers of underground cable networks, placed into pavements of roadways and footways, are often subjected to premature damage posing a threat to traffic safety. That is why the investigation was undertaken to increase the durability of precast concrete covers. New concrete mixtures for precast elements as well as the structure of elements (the type of a chassis, the number and arrangement of reinforcement bars) were designed. Experimental research into the load bearing capacity of concrete elements manufactured in multiple precast plants according to the assumed mix design was carried out. The impact of the type of cement, chemical admixtures and fibre reinforcement on the load capacity of precast concrete elements was assessed. The high effectiveness of fibre reinforcement enhancing the load bearing capacity of concrete covers was found. © Instytut Badawczy Dróg i Mostów, Warszawa 2012.


Ranachowski P.,Instytut Podstawowych Problemow Techniki PAN | Rejmund F.,Instytut Podstawowych Problemow Techniki PAN | Ranachowski Z.,Instytut Podstawowych Problemow Techniki PAN | Pawelek A.,Instytut Metalurgii i Inzynierii Materialowej PAN | And 2 more authors.
Przeglad Elektrotechniczny | Year: 2012

The paper presents the research of the influence of the mullite phase on the short- and long-term mechanical strength of the electrotechnical porcelain of different types (C 110, C 112, C 120 and C 130). The total mullite phase content, size and distribution of precipitates and dispersed single crystals in the glassy matrix were considered. During investigation mechanoacoustic and microscopic techniques as well as ultrasonic testing were used. The role of the mullite phase in the increase of resistance to aging processes of electrical porcelain of various types was described.


Knor G.,Instytut Podstawowych Problemow Techniki PAN | Glinicki M.A.,Instytut Podstawowych Problemow Techniki PAN | Holnicki-Szulc J.,Instytut Podstawowych Problemow Techniki PAN
Road and Bridges - Drogi i Mosty | Year: 2012

The paper presents the procedure of determining the thermophysical properties of concrete: heat of hardening, thermal conductivity and specific heat, which is based on point temperature measurements in a cylindrical mold and the numerical solution of the inverse heat transfer problem. The procedure was tested on concrete materials made with high-calcium fly ashes. The obtained results show good agreement with the real values of individual parameters and can be used to determine the temperature field in the object of any complex shape. © Instytut Badawczy Dróg i Mostów, Warszawa 2012.


Ranachowski P.,Instytut Podstawowych Problemow Techniki PAN | Rejmund F.,Instytut Podstawowych Problemow Techniki PAN | Ranachowski Z.,Instytut Podstawowych Problemow Techniki PAN | Pawelek A.,Instytut Metalurgii i Inzynierii Materialowej PAN | And 2 more authors.
Przeglad Elektrotechniczny | Year: 2014

The paper presents the microscopic and mechanoacoustic study of degradation processes of the porcelain material C 110 type. Smallsized samples, derived from the low voltage insulator, were subjected to a slow, quasi-static compression, with simultaneous recording of acoustic emission descriptors. There were distinguished consecutive stages of the material degradation. Obtained results were compared with the images of the microstructure of low-voltage insulator materials after many years of operation. On this basis, there were distinguished the factors determinant of the short-term strength of porcelain and its resistance to ageing processes under operating conditions. © 2014, Wydawnictwo SIGMA - N O T Sp. z o.o. All rights reserved.

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