V. Mironov, I. Pundienė, A. Tatarinov, J. Baroninsh
Abstract The application of small-sized metal fillers (SMF) provides a combination of high bulk density, increased durability and ferromagnetic properties of composite materials on the cement basis. However, the total strength of the composite can be compromised by poor adhesion of metal particles with the cement matrix. The use of versatile additives like microsilica and metakaolin is able to improve the structural integrity and mechanical properties of heavy concretes. The paper considers the results of a study using specimens of heavy concretes with SMF aiming to estimate its strength, structural features and ultrasonic parameters. It was found that the contact of SMF particles with the cement was not perfect, since the voids appeared between them and the cement matrix during the cement hydration process (exothermal reaction). Due to the border porosity, the specimens with the metal fillers have lower compressive strength, lower ultrasound velocity and increased frequency slope of attenuation. Microsilica and metakaolin additives facilitate better contact zone between the cement matrix and metal fillers.
{"title":"A Study of Metal-Cement Composites with Additives","authors":"V. Mironov, I. Pundienė, A. Tatarinov, J. Baroninsh","doi":"10.1515/cons-2014-0008","DOIUrl":"https://doi.org/10.1515/cons-2014-0008","url":null,"abstract":"Abstract The application of small-sized metal fillers (SMF) provides a combination of high bulk density, increased durability and ferromagnetic properties of composite materials on the cement basis. However, the total strength of the composite can be compromised by poor adhesion of metal particles with the cement matrix. The use of versatile additives like microsilica and metakaolin is able to improve the structural integrity and mechanical properties of heavy concretes. The paper considers the results of a study using specimens of heavy concretes with SMF aiming to estimate its strength, structural features and ultrasonic parameters. It was found that the contact of SMF particles with the cement was not perfect, since the voids appeared between them and the cement matrix during the cement hydration process (exothermal reaction). Due to the border porosity, the specimens with the metal fillers have lower compressive strength, lower ultrasound velocity and increased frequency slope of attenuation. Microsilica and metakaolin additives facilitate better contact zone between the cement matrix and metal fillers.","PeriodicalId":22024,"journal":{"name":"Stroitel stvo nauka i obrazovanie [Construction Science and Education]","volume":"31 1","pages":"16 - 20"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89624790","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract The article presents the results of the research on carbonation and chloride induced corrosion mechanisms in reinforced concrete structures, based on three commercially available concrete admixtures: Xypex Admix C-1000, Penetron Admix and Elkem Microsilica. Carbonation takes place due to carbon dioxide diffusion, which in the required amount is present in the air. Chlorides penetrate concrete in case of the use of deicing salt or structure exploitation in marine atmosphere. Based on the implemented research, Elkem Microsilica is the recommended additive for the use in aggressive environmental conditions. Use of Xypex Admix C-1000 and Penetron Admix have only average resistance to the aggressive environmental impact.
{"title":"Influence of Additives on Reinforced Concrete Durability","authors":"Darja Neverkoviča, A. Korjakins","doi":"10.1515/cons-2014-0009","DOIUrl":"https://doi.org/10.1515/cons-2014-0009","url":null,"abstract":"Abstract The article presents the results of the research on carbonation and chloride induced corrosion mechanisms in reinforced concrete structures, based on three commercially available concrete admixtures: Xypex Admix C-1000, Penetron Admix and Elkem Microsilica. Carbonation takes place due to carbon dioxide diffusion, which in the required amount is present in the air. Chlorides penetrate concrete in case of the use of deicing salt or structure exploitation in marine atmosphere. Based on the implemented research, Elkem Microsilica is the recommended additive for the use in aggressive environmental conditions. Use of Xypex Admix C-1000 and Penetron Admix have only average resistance to the aggressive environmental impact.","PeriodicalId":22024,"journal":{"name":"Stroitel stvo nauka i obrazovanie [Construction Science and Education]","volume":"6 1","pages":"21 - 26"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87280904","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract A new method is proposed that will help predict the remaining service life of concrete bridges based on quantitative deterioration research. It is suggested that for a given degree of damage (stage) and corresponding environmental and bridge design factors, there is only one time value. In that way it is possible to calculate the deterioration rate for given environmental and bridge design factors shared by many different bridges. The method can be used to calculate the key parameters for corrosion deterioration, thereby enabling the prediction of the remaining service life of a bridge using DuraCrete deterioration models
{"title":"Predicting The Service Life Of Concrete Bridges Based On Quantitative Research","authors":"K. Gode","doi":"10.2478/cons-2014-0002","DOIUrl":"https://doi.org/10.2478/cons-2014-0002","url":null,"abstract":"Abstract A new method is proposed that will help predict the remaining service life of concrete bridges based on quantitative deterioration research. It is suggested that for a given degree of damage (stage) and corresponding environmental and bridge design factors, there is only one time value. In that way it is possible to calculate the deterioration rate for given environmental and bridge design factors shared by many different bridges. The method can be used to calculate the key parameters for corrosion deterioration, thereby enabling the prediction of the remaining service life of a bridge using DuraCrete deterioration models","PeriodicalId":22024,"journal":{"name":"Stroitel stvo nauka i obrazovanie [Construction Science and Education]","volume":"61 1","pages":"11 - 18"},"PeriodicalIF":0.0,"publicationDate":"2014-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89178977","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract This paper presents the analysis of air pollution monitoring and evaluation results in the center of Riga City. The air quality reports have pointed out that road traffic and road infrastructure are the main issues of air pollution in the center of Riga. However, none of the reports validated this assumption considering actual traffic flow data. In the present article, the air pollution data have been collected and analyzed in the context with traffic flow. The statistical analysis of both the air pollution and traffic flow data was performed and the correlation between them was established and evaluated. Finally, the conclusions and recommendations for further improvements of the methodology of measurements necessary for successful air quality assessment in the urban areas and particularly in Riga city are given.
{"title":"Evaluation Of Air Pollution Measurements In Urban Environment Considering Traffic Intensity","authors":"A. Zariņš, J. Smirnovs, Raitis Lācis","doi":"10.2478/cons-2014-0005","DOIUrl":"https://doi.org/10.2478/cons-2014-0005","url":null,"abstract":"Abstract This paper presents the analysis of air pollution monitoring and evaluation results in the center of Riga City. The air quality reports have pointed out that road traffic and road infrastructure are the main issues of air pollution in the center of Riga. However, none of the reports validated this assumption considering actual traffic flow data. In the present article, the air pollution data have been collected and analyzed in the context with traffic flow. The statistical analysis of both the air pollution and traffic flow data was performed and the correlation between them was established and evaluated. Finally, the conclusions and recommendations for further improvements of the methodology of measurements necessary for successful air quality assessment in the urban areas and particularly in Riga city are given.","PeriodicalId":22024,"journal":{"name":"Stroitel stvo nauka i obrazovanie [Construction Science and Education]","volume":"34 1","pages":"29 - 34"},"PeriodicalIF":0.0,"publicationDate":"2014-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84417041","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
G. Skripkiūnas, G. Girskas, J. Malaiškienė, Evaldas Šemelis
Abstract Concrete pavement blocks were formed and the following properties were investigated after 7 days of curing: density, tensile splitting strength, freezing-thawing resistance, using de-icing salts in one-sided way, and abrasion resistance. The scattering of the values of density and tensile splitting strength of the concrete pavement blocks in the pallet during the process of manufacture was examined. It was determined that the values of density and splitting tensile strength were similar in the diagonals of the pallet. Bigger changes were seen on the edges of the tray. The variation coefficients of the examined properties ranged from 0.5 % to 15.6 %. The biggest scattering of research results was noted in strength.
{"title":"Variation Of Characteristics Of Vibropressed Concrete Pavement Blocks","authors":"G. Skripkiūnas, G. Girskas, J. Malaiškienė, Evaldas Šemelis","doi":"10.2478/cons-2014-0004","DOIUrl":"https://doi.org/10.2478/cons-2014-0004","url":null,"abstract":"Abstract Concrete pavement blocks were formed and the following properties were investigated after 7 days of curing: density, tensile splitting strength, freezing-thawing resistance, using de-icing salts in one-sided way, and abrasion resistance. The scattering of the values of density and tensile splitting strength of the concrete pavement blocks in the pallet during the process of manufacture was examined. It was determined that the values of density and splitting tensile strength were similar in the diagonals of the pallet. Bigger changes were seen on the edges of the tray. The variation coefficients of the examined properties ranged from 0.5 % to 15.6 %. The biggest scattering of research results was noted in strength.","PeriodicalId":22024,"journal":{"name":"Stroitel stvo nauka i obrazovanie [Construction Science and Education]","volume":"53 1","pages":"24 - 28"},"PeriodicalIF":0.0,"publicationDate":"2014-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84699175","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract This study describes the cult buildings, properties and specifics of the cult building microclimate-related problems, based on the statutory requirements, also considering optimal parameters of the air. This study presents the results of indoor air monitoring in the cult building. The proposed methodology was evaluated in Riga All Saints Orthodox Church. During the evaluation, practical measurements of indoor air quality were taken. The recommendations for improvement of temperature/ moisture conditions were presented.
{"title":"Evaluation Of Temperature And Humidity Regime In An Orthodox Church","authors":"J. Nazarova, A. Borodinecs","doi":"10.2478/cons-2014-0003","DOIUrl":"https://doi.org/10.2478/cons-2014-0003","url":null,"abstract":"Abstract This study describes the cult buildings, properties and specifics of the cult building microclimate-related problems, based on the statutory requirements, also considering optimal parameters of the air. This study presents the results of indoor air monitoring in the cult building. The proposed methodology was evaluated in Riga All Saints Orthodox Church. During the evaluation, practical measurements of indoor air quality were taken. The recommendations for improvement of temperature/ moisture conditions were presented.","PeriodicalId":22024,"journal":{"name":"Stroitel stvo nauka i obrazovanie [Construction Science and Education]","volume":"64 1","pages":"19 - 23"},"PeriodicalIF":0.0,"publicationDate":"2014-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84780794","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract The present study is devoted to the evaluation of efficiency of the combined indirect evaporative - compressor water cooling system under various outdoor air humidity conditions of temperate climate. This is a building- based study, which represents the results of the analytical research, conducted in the recently restored 19th century historical building, The Art Museum Riga Bourse. Indirect adiabatic water chiller is equipped with a compressor, and supplies cooled fluid to the conventional air conditioning system, consisting of ventilation cooling coils and fan-coil units on the separated loop. Using the data acquired by the data logging system, we have analyzed the dependence of the cooling plant operation efficiency on outdoor air humidity for the cooling system operation period of the year 2012.
{"title":"Investigation Of Combined Indirect Evaporative Ducted Cooling Equipment Efficiency In Historical Building In Temperate Climate","authors":"Arturs Brahmanis, U. Pelīte","doi":"10.2478/cons-2014-0001","DOIUrl":"https://doi.org/10.2478/cons-2014-0001","url":null,"abstract":"Abstract The present study is devoted to the evaluation of efficiency of the combined indirect evaporative - compressor water cooling system under various outdoor air humidity conditions of temperate climate. This is a building- based study, which represents the results of the analytical research, conducted in the recently restored 19th century historical building, The Art Museum Riga Bourse. Indirect adiabatic water chiller is equipped with a compressor, and supplies cooled fluid to the conventional air conditioning system, consisting of ventilation cooling coils and fan-coil units on the separated loop. Using the data acquired by the data logging system, we have analyzed the dependence of the cooling plant operation efficiency on outdoor air humidity for the cooling system operation period of the year 2012.","PeriodicalId":22024,"journal":{"name":"Stroitel stvo nauka i obrazovanie [Construction Science and Education]","volume":"120 1","pages":"10 - 4"},"PeriodicalIF":0.0,"publicationDate":"2014-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89324565","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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