A. Mačanovskis, A. Krasņikovs, Iluta Spruģe, G. Sahmenko, A. Lukasenoks
Abstract Crack formation during exploitation considerably decreases durability of concrete structures. Capillary hydro insulation is an integral crystalline waterproofing system ensuing filling of micro cracks, pores and capillaries with an insoluble crystalline formation. In order to evaluate self-healing effect of this system, fiber concrete beams were initially pre-cracked, then treated with capillary insulation and repeatedly tested under bending. Water permeability and frost resistance tests were also realized in order to evaluate long-term performance of the capillary insulation.
{"title":"Mechanical Properties and Self-Healing Effect of Concrete Containing Capillary Hydro Insulation Admixture","authors":"A. Mačanovskis, A. Krasņikovs, Iluta Spruģe, G. Sahmenko, A. Lukasenoks","doi":"10.1515/cons-2016-0003","DOIUrl":"https://doi.org/10.1515/cons-2016-0003","url":null,"abstract":"Abstract Crack formation during exploitation considerably decreases durability of concrete structures. Capillary hydro insulation is an integral crystalline waterproofing system ensuing filling of micro cracks, pores and capillaries with an insoluble crystalline formation. In order to evaluate self-healing effect of this system, fiber concrete beams were initially pre-cracked, then treated with capillary insulation and repeatedly tested under bending. Water permeability and frost resistance tests were also realized in order to evaluate long-term performance of the capillary insulation.","PeriodicalId":22024,"journal":{"name":"Stroitel stvo nauka i obrazovanie [Construction Science and Education]","volume":"12 1","pages":"17 - 21"},"PeriodicalIF":0.0,"publicationDate":"2016-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82574951","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 Concrete is a composite material composed of a binder, aggregates, water and additives. Mixing of cement with water results in a number of chemical reactions known as cement hydration. Heating of concrete results in dehydration processes of cement minerals and new hydration products, which disintegrate the microstructure of concrete. This article reviews results of research conducted with Portland and alumina cement with conventional and refractory concrete aggregates. In civic buildings such common fillers as gravel, granite, dolomite or expanded clay are usually used. It is important to point out the differences between fillers because they constitute the majority of the concrete volume.
{"title":"The Mechanism of Disintegration of Cement Concrete at High Temperatures","authors":"Vytautas Jocius, G. Skripkiūnas","doi":"10.1515/cons-2016-0001","DOIUrl":"https://doi.org/10.1515/cons-2016-0001","url":null,"abstract":"Abstract Concrete is a composite material composed of a binder, aggregates, water and additives. Mixing of cement with water results in a number of chemical reactions known as cement hydration. Heating of concrete results in dehydration processes of cement minerals and new hydration products, which disintegrate the microstructure of concrete. This article reviews results of research conducted with Portland and alumina cement with conventional and refractory concrete aggregates. In civic buildings such common fillers as gravel, granite, dolomite or expanded clay are usually used. It is important to point out the differences between fillers because they constitute the majority of the concrete volume.","PeriodicalId":22024,"journal":{"name":"Stroitel stvo nauka i obrazovanie [Construction Science and Education]","volume":"28 1","pages":"4 - 9"},"PeriodicalIF":0.0,"publicationDate":"2016-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90170871","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 Hydraulic concrete is a composite material that consists of coarse and fine aggregates and a binder, which transforms from liquid to solid state while curing and is exposed to destructive impacts during exploitation. The research was carried out with various cements – Portland cement, slag Portland cement, slag cement and limestone. The results of research showed that quantity of slag in hardened Portland cement paste influences freezing-thawing of concrete for hydraulic structures. Hydraulic concrete under impact of the Baltic Sea is influenced by sea water and freezing and thawing cycles. Under the mentioned impacts exerted simultaneously, experiment results enable assessment of durability of hydraulic concrete. The objective of the work is to assess the impact of the environment of the Baltic Sea on changes in properties of hydraulic concrete after cyclic freezing and thawing.
{"title":"Influence of Mineral Additives on Environmental Resistance of Concrete","authors":"R. Lebedeva, G. Skripkiūnas, A. Kičaitė","doi":"10.1515/cons-2016-0002","DOIUrl":"https://doi.org/10.1515/cons-2016-0002","url":null,"abstract":"Abstract Hydraulic concrete is a composite material that consists of coarse and fine aggregates and a binder, which transforms from liquid to solid state while curing and is exposed to destructive impacts during exploitation. The research was carried out with various cements – Portland cement, slag Portland cement, slag cement and limestone. The results of research showed that quantity of slag in hardened Portland cement paste influences freezing-thawing of concrete for hydraulic structures. Hydraulic concrete under impact of the Baltic Sea is influenced by sea water and freezing and thawing cycles. Under the mentioned impacts exerted simultaneously, experiment results enable assessment of durability of hydraulic concrete. The objective of the work is to assess the impact of the environment of the Baltic Sea on changes in properties of hydraulic concrete after cyclic freezing and thawing.","PeriodicalId":22024,"journal":{"name":"Stroitel stvo nauka i obrazovanie [Construction Science and Education]","volume":"12 1","pages":"10 - 16"},"PeriodicalIF":0.0,"publicationDate":"2016-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84609571","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 Materials used for the study: Portland cement CEM I 42.5 R, 4/16 gravel, 0/4 sand. The fine aggregate in four concrete mixtures was substituted with steel cord scrap added at 1.5 %, 3.0 % and 4.5 %. Water absorption and compressive strength was measured in concrete specimens after 7 and 28 days of curing. Total, closed and open porosity was measured in the modified concrete specimens. The tests of predicted freeze-thaw cycles were done. Test results showed that the substitution of fine aggregate with steel cord scrap results in lower water absorption and higher compressive strength in the modified concrete specimens. The porosity parameters have also changed: the closed porosity has increased and consequently the freeze-thaw resistance of modified concrete has improved.
研究材料:波特兰水泥CEM I 42.5 R, 4/16碎石，0/4砂。用添加量分别为1.5%、3.0%和4.5%的钢丝帘线废钢代替4种混凝土混合料中的细骨料。分别在养护7天和28天后测定混凝土试样的吸水率和抗压强度。测定了改性混凝土试件的总孔隙率、闭孔隙率和开孔隙率。对预测的冻融循环进行了试验。试验结果表明，用钢丝帘片代替细骨料，改性混凝土试样的吸水率降低，抗压强度提高。孔隙率参数也发生了变化:封闭孔隙率增加，从而提高了改性混凝土的抗冻融性能。
{"title":"The Use of Steel Cord Scrap in Concrete","authors":"G. Girskas, D. Nagrockienė","doi":"10.1515/cons-2016-0004","DOIUrl":"https://doi.org/10.1515/cons-2016-0004","url":null,"abstract":"Abstract Materials used for the study: Portland cement CEM I 42.5 R, 4/16 gravel, 0/4 sand. The fine aggregate in four concrete mixtures was substituted with steel cord scrap added at 1.5 %, 3.0 % and 4.5 %. Water absorption and compressive strength was measured in concrete specimens after 7 and 28 days of curing. Total, closed and open porosity was measured in the modified concrete specimens. The tests of predicted freeze-thaw cycles were done. Test results showed that the substitution of fine aggregate with steel cord scrap results in lower water absorption and higher compressive strength in the modified concrete specimens. The porosity parameters have also changed: the closed porosity has increased and consequently the freeze-thaw resistance of modified concrete has improved.","PeriodicalId":22024,"journal":{"name":"Stroitel stvo nauka i obrazovanie [Construction Science and Education]","volume":"69 1","pages":"22 - 26"},"PeriodicalIF":0.0,"publicationDate":"2016-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83820328","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 task of building energy-efficiency is getting more important. Every house owner wishes to save up exploitation costs of heating, cooling, hot water production, ventilation, etc. and find cost-effective investments. One of the ways to reduce greenhouse gas emissions (GHGE) is to minimize the heat transfer through the building by insulating it. Loose heat insulation is a good alternative to traditional board insulation, it is simple in use and cost-effective. Main drawback of this insulation is tendency to compact during exploitation. In the frame of this research composite loose heat insulation is elaborated, consisting on porous mineral foamed glass aggregate and local organic fiber materials (hemp and flaxen shives). Composite bulk insulation is an alternative solution which combines heat insulating properties and mechanical stability.
{"title":"Composite bulk Heat Insulation Made of loose Mineral and Organic Aggregate","authors":"E. Namsone, G. Sahmenko","doi":"10.1515/cons-2015-0002","DOIUrl":"https://doi.org/10.1515/cons-2015-0002","url":null,"abstract":"Abstract The task of building energy-efficiency is getting more important. Every house owner wishes to save up exploitation costs of heating, cooling, hot water production, ventilation, etc. and find cost-effective investments. One of the ways to reduce greenhouse gas emissions (GHGE) is to minimize the heat transfer through the building by insulating it. Loose heat insulation is a good alternative to traditional board insulation, it is simple in use and cost-effective. Main drawback of this insulation is tendency to compact during exploitation. In the frame of this research composite loose heat insulation is elaborated, consisting on porous mineral foamed glass aggregate and local organic fiber materials (hemp and flaxen shives). Composite bulk insulation is an alternative solution which combines heat insulating properties and mechanical stability.","PeriodicalId":22024,"journal":{"name":"Stroitel stvo nauka i obrazovanie [Construction Science and Education]","volume":"24 1","pages":"11 - 17"},"PeriodicalIF":0.0,"publicationDate":"2015-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85967574","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}
Janis Baronins, A. Shishkin, J. Sētiņa, V. Mironovs
Abstract The aim of this study is to obtain high performance boron containing material with sufficient carrying capacity with increased porosity and lower density at the same time. The influence of the different concentrations of Al-W-B powder on the properties of the fresh and hardened HPC was investigated. In the concrete mix design, the allite containing White Portland cement CEM I 52,5 R, granite stone, sand, microsilica, on polycarboxylates based super plasticizer and Al-W-B powder were used. As a source of boron composite material (CM), previously grinded powder containing boron-tungsten fiber and aluminium matrix (CM Al-W-B) was used. Grinding was used for processing of CM Al-W-B powder.
{"title":"Influence of Al-W-B Recycled Composite Material on the Properties of High Performance Concrete","authors":"Janis Baronins, A. Shishkin, J. Sētiņa, V. Mironovs","doi":"10.1515/cons-2015-0001","DOIUrl":"https://doi.org/10.1515/cons-2015-0001","url":null,"abstract":"Abstract The aim of this study is to obtain high performance boron containing material with sufficient carrying capacity with increased porosity and lower density at the same time. The influence of the different concentrations of Al-W-B powder on the properties of the fresh and hardened HPC was investigated. In the concrete mix design, the allite containing White Portland cement CEM I 52,5 R, granite stone, sand, microsilica, on polycarboxylates based super plasticizer and Al-W-B powder were used. As a source of boron composite material (CM), previously grinded powder containing boron-tungsten fiber and aluminium matrix (CM Al-W-B) was used. Grinding was used for processing of CM Al-W-B powder.","PeriodicalId":22024,"journal":{"name":"Stroitel stvo nauka i obrazovanie [Construction Science and Education]","volume":"37 1","pages":"10 - 4"},"PeriodicalIF":0.0,"publicationDate":"2015-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89777536","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}
D. Nagrockienė, Aurelijus Daugėla, Laurynas Zarauskas, G. Skripkiūnas
Abstract Cement as the binding agent in the production of concrete can be replaced with active mineral admixtures. Biofuel combustion fly ash is one of such admixtures. Materials used for the study include Portland cement CEM I 42.5 R, sand of 0/4 fraction, gravel of 4/16 fraction, biofuel fly ash, superplasticizer, and water. Six compositions of concrete were designed by replacing 0 %, 5 %, 10 %, 15 % 20 %, and 25 % of cement with biofuel fly ash. The article analyses the effect of biofuel fly ash content on the properties of concrete. The tests revealed that the increase of biofuel fly ash content up to 20 % increases concrete density and compressive strength after 7 and 28 days of curing and decreases water absorption, with corrected water content by using plasticizing admixture. It has been found that concrete where 20 % of cement is replaced by biofuel ash has higher frost resistance.
摘要在混凝土生产中，水泥作为粘结剂可以用活性矿物外加剂代替。生物燃料燃烧粉煤灰就是其中一种外加剂。研究使用的材料包括波特兰水泥CEM I 42.5 R、0/4分数的沙子、4/16分数的砾石、生物燃料粉煤灰、高效减水剂和水。通过用生物燃料粉煤灰代替0%、5%、10%、15%、20%和25%的水泥，设计了六种混凝土组合。分析了生物燃料粉煤灰掺量对混凝土性能的影响。试验结果表明，生物燃料粉煤灰掺量增加20%后，养护7天和28天后混凝土密度和抗压强度均有所提高，在使用增塑剂修正含水量的情况下，混凝土吸水率有所降低。研究发现，用生物燃料灰替代20%水泥的混凝土具有更高的抗冻性。
{"title":"Influence of Biofuel Combustion Fly Ash on the Properties of Concrete","authors":"D. Nagrockienė, Aurelijus Daugėla, Laurynas Zarauskas, G. Skripkiūnas","doi":"10.1515/cons-2015-0003","DOIUrl":"https://doi.org/10.1515/cons-2015-0003","url":null,"abstract":"Abstract Cement as the binding agent in the production of concrete can be replaced with active mineral admixtures. Biofuel combustion fly ash is one of such admixtures. Materials used for the study include Portland cement CEM I 42.5 R, sand of 0/4 fraction, gravel of 4/16 fraction, biofuel fly ash, superplasticizer, and water. Six compositions of concrete were designed by replacing 0 %, 5 %, 10 %, 15 % 20 %, and 25 % of cement with biofuel fly ash. The article analyses the effect of biofuel fly ash content on the properties of concrete. The tests revealed that the increase of biofuel fly ash content up to 20 % increases concrete density and compressive strength after 7 and 28 days of curing and decreases water absorption, with corrected water content by using plasticizing admixture. It has been found that concrete where 20 % of cement is replaced by biofuel ash has higher frost resistance.","PeriodicalId":22024,"journal":{"name":"Stroitel stvo nauka i obrazovanie [Construction Science and Education]","volume":"17 1","pages":"18 - 23"},"PeriodicalIF":0.0,"publicationDate":"2015-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89392515","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 article analyzes trends of the total final energy consumption in sectors of building materials, residential, and transport industry in Algeria. The total final energy by sector and type of fuel is analyzed. The evolution of the total energy intensity and the impact of energy consumption on the environment are discussed. Consumption per capita in Algeria is 1,058.0 kg of oil equivalent per person, while in Morocco, the country with almost the same number of inhabitants it is 458 Kgoe and in Tunisia it is 843 Kgoe. The total emission of gases is equal to 46 million Tons of CO2, with an average of 3 TECO2 / TOE.
{"title":"Energy Consumption Trends for Industry Segments in Northern Africa","authors":"A. Zerroug, L. Refoufi, E. Dzelzītis","doi":"10.1515/cons-2015-0004","DOIUrl":"https://doi.org/10.1515/cons-2015-0004","url":null,"abstract":"Abstract This article analyzes trends of the total final energy consumption in sectors of building materials, residential, and transport industry in Algeria. The total final energy by sector and type of fuel is analyzed. The evolution of the total energy intensity and the impact of energy consumption on the environment are discussed. Consumption per capita in Algeria is 1,058.0 kg of oil equivalent per person, while in Morocco, the country with almost the same number of inhabitants it is 458 Kgoe and in Tunisia it is 843 Kgoe. The total emission of gases is equal to 46 million Tons of CO2, with an average of 3 TECO2 / TOE.","PeriodicalId":22024,"journal":{"name":"Stroitel stvo nauka i obrazovanie [Construction Science and Education]","volume":"4 1","pages":"24 - 30"},"PeriodicalIF":0.0,"publicationDate":"2015-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84119494","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}
J. Malaiškienė, Evaldas Šemelis, G. Girskas, V. Kizinievič
Abstract The aim of this research is to determine the dependences of the physical mechanical properties of vibropressed concrete (pavement blocks) on the type of coarse aggregate used in the main layer. Sustainability of concrete pavement blocks is a really important matter. Five different batches of pavement blocks were produced, changing the consistence ratio of coarse aggregate in the main layer. There are two types of course aggregate: crushed gravel and granite. The consistence of a facing layer was not changed. All tests: density, tensile split strength, water absorption for vibro-pressed concrete units were made according to EN 1338:2003+AC2006.
{"title":"The Dependence of Physical Mechanical Properties of Concrete Pavement Blocks on Coarse Aggregate Type","authors":"J. Malaiškienė, Evaldas Šemelis, G. Girskas, V. Kizinievič","doi":"10.1515/cons-2014-0007","DOIUrl":"https://doi.org/10.1515/cons-2014-0007","url":null,"abstract":"Abstract The aim of this research is to determine the dependences of the physical mechanical properties of vibropressed concrete (pavement blocks) on the type of coarse aggregate used in the main layer. Sustainability of concrete pavement blocks is a really important matter. Five different batches of pavement blocks were produced, changing the consistence ratio of coarse aggregate in the main layer. There are two types of course aggregate: crushed gravel and granite. The consistence of a facing layer was not changed. All tests: density, tensile split strength, water absorption for vibro-pressed concrete units were made according to EN 1338:2003+AC2006.","PeriodicalId":22024,"journal":{"name":"Stroitel stvo nauka i obrazovanie [Construction Science and Education]","volume":"11 1","pages":"11 - 15"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85692944","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 summarizes the IAQ parameters of multi-apartment buildings before and after renovation in Latvia. In a building with natural ventilation system air exchange is significantly dependent on the position of the apartment within the building. If CO2 as an indicator of indoor air quality is analyzed, the results show that inhabitants’ behavior has a considerable impact on IAQ. The planning of adequate investment in buildings to improve energy efficiency and choosing the modern, adequate and effective engineering solutions, it is possible to raise the comfort level of living space and to reduce heat and thermal energy consumption.
{"title":"Indoor Air Quality in Multi-Apartment Buildings before and after Renovation","authors":"Ilze Dimdiņa, Ēriks Krūmiņš, A. Lešinskis","doi":"10.1515/cons-2014-0006","DOIUrl":"https://doi.org/10.1515/cons-2014-0006","url":null,"abstract":"Abstract The article summarizes the IAQ parameters of multi-apartment buildings before and after renovation in Latvia. In a building with natural ventilation system air exchange is significantly dependent on the position of the apartment within the building. If CO2 as an indicator of indoor air quality is analyzed, the results show that inhabitants’ behavior has a considerable impact on IAQ. The planning of adequate investment in buildings to improve energy efficiency and choosing the modern, adequate and effective engineering solutions, it is possible to raise the comfort level of living space and to reduce heat and thermal energy consumption.","PeriodicalId":22024,"journal":{"name":"Stroitel stvo nauka i obrazovanie [Construction Science and Education]","volume":"22 6S 1","pages":"10 - 4"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76523053","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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