L. Tupėnaitė, Viktorija Žilėnaitė, Loreta Kanapeckiene, Masoud Sajjadian, T. Gečys, Lina Sakalauskienė, Jurga Naimaviciene
Although the majority of high-rise buildings are constructed from concrete and steel, there is a growing interest in the new generation of multi-storey timber buildings around the world and several ecologically sustainable structural systems have already been proposed. This research aims to review and compare the highest contemporary timber buildings in terms of economic and environmental efficiency. For this purpose, the Simple Additive Weighting (SAW) method is used. Five high-rise timber buildings are assessed according to the developed system of economic and environmental criteria. According to the multiple criteria assessment results, Mjøsa Tower, currently the tallest timber building in the world, located in Brumunddal, Norway, is ranked in the first place. This study also reveals that high-rise timber buildings are environmental friendly and high economic efficiency can be achieved by using lightweight modern engineered timber products, moreover, prefabrication of elements reduces duration and cost of the project.
{"title":"MULTIPLE CRITERIA ASSESSMENT OF HIGH-RISE TIMBER BUILDINGS","authors":"L. Tupėnaitė, Viktorija Žilėnaitė, Loreta Kanapeckiene, Masoud Sajjadian, T. Gečys, Lina Sakalauskienė, Jurga Naimaviciene","doi":"10.3846/est.2019.11952","DOIUrl":"https://doi.org/10.3846/est.2019.11952","url":null,"abstract":"Although the majority of high-rise buildings are constructed from concrete and steel, there is a growing interest in the new generation of multi-storey timber buildings around the world and several ecologically sustainable structural systems have already been proposed. This research aims to review and compare the highest contemporary timber buildings in terms of economic and environmental efficiency. For this purpose, the Simple Additive Weighting (SAW) method is used. Five high-rise timber buildings are assessed according to the developed system of economic and environmental criteria. According to the multiple criteria assessment results, Mjøsa Tower, currently the tallest timber building in the world, located in Brumunddal, Norway, is ranked in the first place. This study also reveals that high-rise timber buildings are environmental friendly and high economic efficiency can be achieved by using lightweight modern engineered timber products, moreover, prefabrication of elements reduces duration and cost of the project.","PeriodicalId":11839,"journal":{"name":"Engineering Structures and Technologies","volume":"11 1","pages":"87-94"},"PeriodicalIF":0.0,"publicationDate":"2020-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46016766","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}
Y. Tokarev, G. Yakovlev, Z. Saidova, V. Grakhov, A. Buryanov, A.E.M.M. Elrefai
This research is devoted to modification of physical and mechanical properties and structure of a binder based on natural anhydrite. A sedimentary rock siltstone was added into the composition as a mineral ultrafine additive. The presence of aluminosilicate minerals proves that finely ground siltstone can be used as a mineral additive in the composition of the anhydrite binder, accelerating crystallization of gypsum new formations and densifying the structure of gypsum stone. For the first time, the effectiveness of using sodium and ammonium phosphates as hardening activators of an anhydrite binder was shown. Siltstone, added to the composition in the amount from 0 to 5%, lead to up to 40% increase in strength, which is due to the action of siltstone particles as “crystallization centers” and formation of crystalline hydrates of calcium sulfate dihydrate on their surface. Combined action of calcined siltstone and lime leads to a 45% increase in strength due to the additional compaction by new hydration products formed in the course of metakaolin and lime interaction. Microstructural analysis showed that samples with calcined siltstone and lime have a more dense and uniform structure with a lower porosity, compared to those with only natural siltstone.
{"title":"A STUDY ON MECHANICAL PROPERTIES AND STRUCTURE OF ANHYDRITE BINDER MODIFIED BY ULTRA-DISPERSED SILTSTONE","authors":"Y. Tokarev, G. Yakovlev, Z. Saidova, V. Grakhov, A. Buryanov, A.E.M.M. Elrefai","doi":"10.3846/est.2019.11950","DOIUrl":"https://doi.org/10.3846/est.2019.11950","url":null,"abstract":"This research is devoted to modification of physical and mechanical properties and structure of a binder based on natural anhydrite. A sedimentary rock siltstone was added into the composition as a mineral ultrafine additive. The presence of aluminosilicate minerals proves that finely ground siltstone can be used as a mineral additive in the composition of the anhydrite binder, accelerating crystallization of gypsum new formations and densifying the structure of gypsum stone. For the first time, the effectiveness of using sodium and ammonium phosphates as hardening activators of an anhydrite binder was shown. Siltstone, added to the composition in the amount from 0 to 5%, lead to up to 40% increase in strength, which is due to the action of siltstone particles as “crystallization centers” and formation of crystalline hydrates of calcium sulfate dihydrate on their surface. Combined action of calcined siltstone and lime leads to a 45% increase in strength due to the additional compaction by new hydration products formed in the course of metakaolin and lime interaction. Microstructural analysis showed that samples with calcined siltstone and lime have a more dense and uniform structure with a lower porosity, compared to those with only natural siltstone.","PeriodicalId":11839,"journal":{"name":"Engineering Structures and Technologies","volume":"11 1","pages":"78-86"},"PeriodicalIF":0.0,"publicationDate":"2020-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49137889","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}
E. Karpova, G. Skripkiūnas, G. Yakovlev, A. Kičaitė
It is well known that organic waste materials deteriorate the performance of concrete. The impregnation of organic aggregates and their application in combination with other chemical admixtures and mineral additives are used in order to improve the concrete properties in case of their modification by organic components. The current research is focused on the evaluation of impact of multi-walled carbon nanotubes (MWCNT) on the properties of cement systems prepared based on wood sawdust extract (WSE). The setting time, density, consistency, flexural and compressive strength, water absorption tests were undertaken. The retardation effect of (WSE) on the initial and final setting time of cement paste was observed. The additional modification of cement paste with WSE by MWCNT in the dosage of 0.005% by weight of cement (bwoc) did not show the significant changes in initial and final setting time. The application of MWCNT in the dosage of 0.005% bwoc contributed to the increase of early strength of cement mortar prepared with WSE.
{"title":"IMPACT OF MULTI-WALLED CARBON NANOTUBES ON WOOD SAWDUST EXTRACT CEMENT MORTAR","authors":"E. Karpova, G. Skripkiūnas, G. Yakovlev, A. Kičaitė","doi":"10.3846/est.2019.12334","DOIUrl":"https://doi.org/10.3846/est.2019.12334","url":null,"abstract":"It is well known that organic waste materials deteriorate the performance of concrete. The impregnation of organic aggregates and their application in combination with other chemical admixtures and mineral additives are used in order to improve the concrete properties in case of their modification by organic components. The current research is focused on the evaluation of impact of multi-walled carbon nanotubes (MWCNT) on the properties of cement systems prepared based on wood sawdust extract (WSE). The setting time, density, consistency, flexural and compressive strength, water absorption tests were undertaken. The retardation effect of (WSE) on the initial and final setting time of cement paste was observed. The additional modification of cement paste with WSE by MWCNT in the dosage of 0.005% by weight of cement (bwoc) did not show the significant changes in initial and final setting time. The application of MWCNT in the dosage of 0.005% bwoc contributed to the increase of early strength of cement mortar prepared with WSE.","PeriodicalId":11839,"journal":{"name":"Engineering Structures and Technologies","volume":"11 1","pages":"119-124"},"PeriodicalIF":0.0,"publicationDate":"2019-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44108047","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}
S. Makharza, Maryam Faroun, Mohammad Bawwab, I. Afaneh
We reported the fabrication of poly (vinyl alcohol) incorporated with two different sizes of graphene oxide particles. Scanning electron microscopy (SEM) revealed two sizes of graphene oxide, the first size is as prepared GO_300 nm and the second size is 100nm after hard sonication. The alteration in thermal and mechanical properties of PVA/ GO (5, 10, 15, 20%) nanocomposite compering with PVA are mainly due to the uniform dispersion of GO particles in the polymer matrix and huge interfacial interaction between PVA and GO sheets. Differential scanning calorimetry shows obvious changes in thermal characteristics of PVA after mixing with GO particles. The composite samples exhibit a significant finding at different concentrations and size distribution of GO.
{"title":"GRAPHENE OXIDE REINFORCED POLY (VINYL ALCOHOL) NANOCOMPOSITE: FABRICATION AND CHARACTERIZATION FOR THERMAL AND MECHANICAL PROPERTIES INVESTIGATIONS","authors":"S. Makharza, Maryam Faroun, Mohammad Bawwab, I. Afaneh","doi":"10.3846/est.2019.12473","DOIUrl":"https://doi.org/10.3846/est.2019.12473","url":null,"abstract":"We reported the fabrication of poly (vinyl alcohol) incorporated with two different sizes of graphene oxide particles. Scanning electron microscopy (SEM) revealed two sizes of graphene oxide, the first size is as prepared GO_300 nm and the second size is 100nm after hard sonication. The alteration in thermal and mechanical properties of PVA/ GO (5, 10, 15, 20%) nanocomposite compering with PVA are mainly due to the uniform dispersion of GO particles in the polymer matrix and huge interfacial interaction between PVA and GO sheets. Differential scanning calorimetry shows obvious changes in thermal characteristics of PVA after mixing with GO particles. The composite samples exhibit a significant finding at different concentrations and size distribution of GO.","PeriodicalId":11839,"journal":{"name":"Engineering Structures and Technologies","volume":"11 1","pages":"125-129"},"PeriodicalIF":0.0,"publicationDate":"2019-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45976789","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}
"Book ‘On the spatial structure of architectonic objects’ review." Engineering Structures and Technologies, 11(2), pp. 74-77.
《建筑物体的空间结构》，载《工程结构与技术》，11（2），第74-77页。
{"title":"ON MORPHOLOGY OF BUILT-UP SPACE","authors":"O. Kapliński","doi":"10.3846/est.2019.10495","DOIUrl":"https://doi.org/10.3846/est.2019.10495","url":null,"abstract":"\"Book ‘On the spatial structure of architectonic objects’ review.\" Engineering Structures and Technologies, 11(2), pp. 74-77.","PeriodicalId":11839,"journal":{"name":"Engineering Structures and Technologies","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43321235","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}
The article presents single-span composite string steel structure. The article discusses the calculation method for the single-span composite string structure when the load is symmetrical, while the string and bottom cable act as absolutely flexible elements. It presents the way the displacements and the shear force in the supports are calculated for the distributed and concentrated loads. Calculations with a pre-tensioned string are provided. The results are compared with the results obtained with the finite element method program. The conclusions present the results obtained.
{"title":"A SIMPLIFIED CALCULATION METHOD FOR SYMMETRICAL LOADING OF A SINGLE-SPAN COMPOSITE STRING STEEL STRUCTURE","authors":"E. Beivydas","doi":"10.3846/est.2019.11323","DOIUrl":"https://doi.org/10.3846/est.2019.11323","url":null,"abstract":"The article presents single-span composite string steel structure. The article discusses the calculation method for the single-span composite string structure when the load is symmetrical, while the string and bottom cable act as absolutely flexible elements. It presents the way the displacements and the shear force in the supports are calculated for the distributed and concentrated loads. Calculations with a pre-tensioned string are provided. The results are compared with the results obtained with the finite element method program. The conclusions present the results obtained.","PeriodicalId":11839,"journal":{"name":"Engineering Structures and Technologies","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41540772","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}
This paper presents the results of modeling of the potential distribution in DC corrosion tests with the application of the ANSYS Maxwell software in two models: in the form of a single long bar covered with concrete and in the shape of a fragment of the bar cut out together with the core. Material parameters used for input in the ANSYS Maxwell software were adopted from tests performed in aqueous solutions. The results of the simulation led to the conclusion that the corrosion tests on the cores cut out from the structure are universal so that regardless of the concrete conductivity and the advancement of steel corrosion processes they produce correct values of the corrosion rate. Meanwhile, the measurements taken within the structure will always require some measures to limit the range of polarization or allow its estimation.
{"title":"MODELING OF THE REINFORCEMENT POLARIZATION RANGE IN CORROSION TESTS","authors":"T. Jaśniok","doi":"10.3846/est.2019.10658","DOIUrl":"https://doi.org/10.3846/est.2019.10658","url":null,"abstract":"This paper presents the results of modeling of the potential distribution in DC corrosion tests with the application of the ANSYS Maxwell software in two models: in the form of a single long bar covered with concrete and in the shape of a fragment of the bar cut out together with the core. Material parameters used for input in the ANSYS Maxwell software were adopted from tests performed in aqueous solutions. The results of the simulation led to the conclusion that the corrosion tests on the cores cut out from the structure are universal so that regardless of the concrete conductivity and the advancement of steel corrosion processes they produce correct values of the corrosion rate. Meanwhile, the measurements taken within the structure will always require some measures to limit the range of polarization or allow its estimation.","PeriodicalId":11839,"journal":{"name":"Engineering Structures and Technologies","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47525624","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}
The article analyses behavior of compressed concrete cylinders which were strengthened with external high performance fiber reinforced cementitious composite (HPFRCC) layer. Two different HPFRCC materials were used for the strengthening, which differed in fiber type. Two different types of loading were applied as well. The load was transferred through the whole cross section of the strengthened element and through the core – internal concrete. Loading through the whole cross section allows to validate the mixture law. Loading through the internal concrete allows to investigate the confinement effect. Comparison of theoretically calculated and experimental strength shows that mixture law and confinement effect is valid. Confinement by HPFRCC allowed to increase the strength of concrete about 4 times, but the ultimate strain remains similar. The strength of elements loaded through the whole surface has increased much more and additionally the ultimate strain has increased too.
{"title":"INFLUENCE OF HPFRCC COMPRESSIVE STRENGTH AND CONFINEMENT ON CONCRETE","authors":"D. Kumar, M. Daugevičius","doi":"10.3846/est.2019.10679","DOIUrl":"https://doi.org/10.3846/est.2019.10679","url":null,"abstract":"The article analyses behavior of compressed concrete cylinders which were strengthened with external high performance fiber reinforced cementitious composite (HPFRCC) layer. Two different HPFRCC materials were used for the strengthening, which differed in fiber type. Two different types of loading were applied as well. The load was transferred through the whole cross section of the strengthened element and through the core – internal concrete. Loading through the whole cross section allows to validate the mixture law. Loading through the internal concrete allows to investigate the confinement effect. Comparison of theoretically calculated and experimental strength shows that mixture law and confinement effect is valid. Confinement by HPFRCC allowed to increase the strength of concrete about 4 times, but the ultimate strain remains similar. The strength of elements loaded through the whole surface has increased much more and additionally the ultimate strain has increased too.","PeriodicalId":11839,"journal":{"name":"Engineering Structures and Technologies","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43536266","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}
In the paper the effectiveness of external steel and composite reinforcement was compared and discussed. The differences between the physical features of both materials, which are relevant for their use as additional, external reinforcement of the support zones, were presented. The results of authors’ and others experimental studies on strengthening reinforced concrete slabs by using external longitudinal reinforcement in the form of CFRP strips and steel flat bars, as well as by increasing the stiffness od support zone with steel sheets and CFRP tapes, were discussed. It was stated that moderate effectiveness of composite materials as external punching shear reinforcement resulted from higher deformability of CFRP as well as premature deboning (prior to rupture of fibers).
{"title":"HOW TO STRENGTHEN FLAT SLABS ON PUNCHING SHEAR – TRADITIONALLY WITH STEEL OR INNOVATIVE, BY USING FIBER COMPOSITE MATERIALS?","authors":"T. Urban, M. Gołdyn","doi":"10.3846/EST.2019.10657","DOIUrl":"https://doi.org/10.3846/EST.2019.10657","url":null,"abstract":"In the paper the effectiveness of external steel and composite reinforcement was compared and discussed. The differences between the physical features of both materials, which are relevant for their use as additional, external reinforcement of the support zones, were presented. The results of authors’ and others experimental studies on strengthening reinforced concrete slabs by using external longitudinal reinforcement in the form of CFRP strips and steel flat bars, as well as by increasing the stiffness od support zone with steel sheets and CFRP tapes, were discussed. It was stated that moderate effectiveness of composite materials as external punching shear reinforcement resulted from higher deformability of CFRP as well as premature deboning (prior to rupture of fibers).","PeriodicalId":11839,"journal":{"name":"Engineering Structures and Technologies","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48014235","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}
The article presents the author’s proposal to determine the parameters of the Mentérey–Willam (M-W-3) plasticity surface of the homogeneous masonry elements made of autoclaved aerated concrete (AAC) and vertically hollow calcium-silicate (Ca-Si) masonry units. The uniaxial and triaxial tests of AAC samples in a standard Hoek’s cell was performed while the hollow units made of silicate were tested on a custom-made test stand. By performing statistical analyses, the shape of the meridians of the surface was determined, and then the eccentricity e of the elliptical function was identified.
{"title":"PROPOSAL OF PROCEDURE FOR IDENTIFICATION OF MENÉTREY–WILLAM (M-W-3) PLASTICITY SURFACE OF HOMOGENEOUS AND HOLLOW MASONRY UNITS","authors":"R. Jasiński","doi":"10.3846/EST.2019.10582","DOIUrl":"https://doi.org/10.3846/EST.2019.10582","url":null,"abstract":"The article presents the author’s proposal to determine the parameters of the Mentérey–Willam (M-W-3) plasticity surface of the homogeneous masonry elements made of autoclaved aerated concrete (AAC) and vertically hollow calcium-silicate (Ca-Si) masonry units. The uniaxial and triaxial tests of AAC samples in a standard Hoek’s cell was performed while the hollow units made of silicate were tested on a custom-made test stand. By performing statistical analyses, the shape of the meridians of the surface was determined, and then the eccentricity e of the elliptical function was identified.","PeriodicalId":11839,"journal":{"name":"Engineering Structures and Technologies","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42592431","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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