In critical earthquake-prone regions, many kinds of old-dated industrial facilities having structural deficiencies exist. Evaluation of seismic performance of these buildings to reach a sufficient level is quite vital. This paper scopes seismic performance assessment of an existing industrial structure. In the study, a comprehensive methodology is presented to carry out the seismic evaluation process of the buildings. The entire process is illustrated using a case study from an existing industrial precast facility. In this scope, initially, construction system, geometry, layout and material properties of the examined structure were determined through lab studies and site surveys to assess the performance level. Secondly, the current status of the structure was modeled using Midas Gen finite element software and a series of analyses were performed to reveal the seismic performance. In the analyses of seismic performance, the non-linear pushover analyses method was employed in seismic code. In the model the fiber and lumped hinges were assigned to the columns and beams, respectively. The strains occurring in the column cross-sections were calculated using the curvature values obtained from the corresponding members assigned hinges. These values were compared with the limit values which were specified in the code. It is concluded that this case study presents a practical approach for engineering applications regarding the seismic evaluation of industrial structures from the perspective of update codes.
{"title":"A methodological approach for seismic performance of existing single-storey industrial RC precast facilities","authors":"B. Sayın, Turgay Çoşgun, Baris Gunes","doi":"10.7764/rdlc.21.1.167","DOIUrl":"https://doi.org/10.7764/rdlc.21.1.167","url":null,"abstract":"In critical earthquake-prone regions, many kinds of old-dated industrial facilities having structural deficiencies exist. Evaluation of seismic performance of these buildings to reach a sufficient level is quite vital. This paper scopes seismic performance assessment of an existing industrial structure. In the study, a comprehensive methodology is presented to carry out the seismic evaluation process of the buildings. The entire process is illustrated using a case study from an existing industrial precast facility. In this scope, initially, construction system, geometry, layout and material properties of the examined structure were determined through lab studies and site surveys to assess the performance level. Secondly, the current status of the structure was modeled using Midas Gen finite element software and a series of analyses were performed to reveal the seismic performance. In the analyses of seismic performance, the non-linear pushover analyses method was employed in seismic code. In the model the fiber and lumped hinges were assigned to the columns and beams, respectively. The strains occurring in the column cross-sections were calculated using the curvature values obtained from the corresponding members assigned hinges. These values were compared with the limit values which were specified in the code. It is concluded that this case study presents a practical approach for engineering applications regarding the seismic evaluation of industrial structures from the perspective of update codes.","PeriodicalId":54473,"journal":{"name":"Revista de la Construccion","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71304562","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study presents the physical and the mechanical properties of C class fly ash (FA) based lightweight geopolymer mortars produced with expanded vermiculite (EV) aggregate. The FA was activated with NaOH containing 12%, 14% and 16% sodium by weight. The volumetric ratios of EV/FA in the samples were chosen as 2,4 and 6 in the study. The liquid/solid ratio 0.23, 0.26 and 0.29. Lightweight geopolymer mortar (LGM) samples were produced by mixing FA, EV, NaOH and water in a mixer. The samples placed in molds were exposed to activation temperature of 100°C for 24 hours in the oven. The samples taken out of the oven were demoulded and kept in air curing for 28 days at 20°C±2°C room temperature. After curing, unit weight, apparent porosity, water absorption ratio, ultrasonic pulse velocity (UPV), flexural strength and compressive strength tests were performed on the samples. In addition, the thermal conductivity coefficients of the samples were determined. As a result of the experiment, a compressive strength varying between 0.59 MPa and 3.81 MPa was obtained in lightweight geopolymers samples with a unit weight between 906 kg/m3 and 1477 kg/m3. Expanded vermiculite showed a good performance on thermal conductivity of LGMs and a decrease in thermal conductivity up to the 0.094 W/mK was observed.
{"title":"Physical and mechanical properties of C class fly ash based lightweight geopolymer mortar produced with expanded vermiculite aggregate","authors":"M. Kaya, F. Köksal","doi":"10.7764/rdlc.21.1.21","DOIUrl":"https://doi.org/10.7764/rdlc.21.1.21","url":null,"abstract":"This study presents the physical and the mechanical properties of C class fly ash (FA) based lightweight geopolymer mortars produced with expanded vermiculite (EV) aggregate. The FA was activated with NaOH containing 12%, 14% and 16% sodium by weight. The volumetric ratios of EV/FA in the samples were chosen as 2,4 and 6 in the study. The liquid/solid ratio 0.23, 0.26 and 0.29. Lightweight geopolymer mortar (LGM) samples were produced by mixing FA, EV, NaOH and water in a mixer. The samples placed in molds were exposed to activation temperature of 100°C for 24 hours in the oven. The samples taken out of the oven were demoulded and kept in air curing for 28 days at 20°C±2°C room temperature. After curing, unit weight, apparent porosity, water absorption ratio, ultrasonic pulse velocity (UPV), flexural strength and compressive strength tests were performed on the samples. In addition, the thermal conductivity coefficients of the samples were determined. As a result of the experiment, a compressive strength varying between 0.59 MPa and 3.81 MPa was obtained in lightweight geopolymers samples with a unit weight between 906 kg/m3 and 1477 kg/m3. Expanded vermiculite showed a good performance on thermal conductivity of LGMs and a decrease in thermal conductivity up to the 0.094 W/mK was observed.","PeriodicalId":54473,"journal":{"name":"Revista de la Construccion","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71304617","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
During last few decades, the researchers have developed new structural systems which have no or minor damage after being hit by severe events like earthquake. Development of self-centering wall having alternative energy dissipation mechanisms was one of these achievements. A wide variety of rocking wall systems, such as jointed walls, hybrid walls, precast walls with end columns (PreWEC), and PreWEC core wall systems, are proposed and studied. This paper describes an analytical investigation of the lateral load behavior of two new types of hybrid rocking wall systems. Core rocking wall is achieved by merging four single hybrid rocking walls and coupled rocking wall is accomplished by coupling two rocking walls using embedded reinforced concrete beams. The concept of coupling hybrid rocking walls using embedded reinforced coupling beam is emerged from previous coupled conventional shear walls studies. As single rocking wall system, in coupled and core rocking wall, post-tensioning tendons are used as a mean to provide self-centering force, and mild steel bars are used to dissipate energy. The nonlinear behavior of the wall is due to the gap opening at the base joint. Three-dimensional finite element model of each system was developed. The stress distribution, crack propagation, and critical sections of these systems are investigated. The effect of spalling concrete cover in the toe region due to rocking action is explained. In addition, the reduction in stiffness and lateral load resisting capacity of the systems due to cracks is monitored. Finally, the lateral load behavior of single rocking walls is compared to that of core and coupled rocking wall systems.
{"title":"Numerical investigation of the lateral load behavior of core and coupled rocking walls","authors":"A. Sarı, S. Sorosh","doi":"10.7764/rdlc.21.1.36","DOIUrl":"https://doi.org/10.7764/rdlc.21.1.36","url":null,"abstract":"During last few decades, the researchers have developed new structural systems which have no or minor damage after being hit by severe events like earthquake. Development of self-centering wall having alternative energy dissipation mechanisms was one of these achievements. A wide variety of rocking wall systems, such as jointed walls, hybrid walls, precast walls with end columns (PreWEC), and PreWEC core wall systems, are proposed and studied. This paper describes an analytical investigation of the lateral load behavior of two new types of hybrid rocking wall systems. Core rocking wall is achieved by merging four single hybrid rocking walls and coupled rocking wall is accomplished by coupling two rocking walls using embedded reinforced concrete beams. The concept of coupling hybrid rocking walls using embedded reinforced coupling beam is emerged from previous coupled conventional shear walls studies. As single rocking wall system, in coupled and core rocking wall, post-tensioning tendons are used as a mean to provide self-centering force, and mild steel bars are used to dissipate energy. The nonlinear behavior of the wall is due to the gap opening at the base joint. Three-dimensional finite element model of each system was developed. The stress distribution, crack propagation, and critical sections of these systems are investigated. The effect of spalling concrete cover in the toe region due to rocking action is explained. In addition, the reduction in stiffness and lateral load resisting capacity of the systems due to cracks is monitored. Finally, the lateral load behavior of single rocking walls is compared to that of core and coupled rocking wall systems.","PeriodicalId":54473,"journal":{"name":"Revista de la Construccion","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71304685","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Praburanganathan Selvaraj, S. Chithra, N. Divyah, S. N, Yeddula Bharath Simha Reddy, V. S
The current study aimed to analyse the viability of incorporating the post cryogenic discarded rubber and the air-cooled slag as an aggregate in partial replacement of stone dust in fly ash bricks production. A range of mechanical, non-destructive, and microstructural tests was performed on bricks thus produced by incorporating rubber and slag aggregates in various dosages (i.e., 5, 10, 15, 20 and 25% by stone dust weight). The result revealed that the compressive strength dropped from 71 to 43 % in the case of rubber aggregate replacement. Morphology study confirms that the rubber aggregates resulted in the porous microstructure of the bricks and leads to lesser unit weight and lighter structure. The rubber may be used as a lightweight aggregate in the brick possibly as it reduces the density of the final product. However, the use of rubber in bricks needs to be cautiously designed to get hold of productive solutions at the end. The findings demonstrate that the copper slag substitution of up to 15%, found to be enhanced the strength properties and it will be a better choice for low-cost construction as a promising alternative construction material.
{"title":"Value-added waste substitution using slag and rubber aggregates in the sustainable and eco-friendly compressed brick production","authors":"Praburanganathan Selvaraj, S. Chithra, N. Divyah, S. N, Yeddula Bharath Simha Reddy, V. S","doi":"10.7764/rdlc.21.1.5","DOIUrl":"https://doi.org/10.7764/rdlc.21.1.5","url":null,"abstract":"The current study aimed to analyse the viability of incorporating the post cryogenic discarded rubber and the air-cooled slag as an aggregate in partial replacement of stone dust in fly ash bricks production. A range of mechanical, non-destructive, and microstructural tests was performed on bricks thus produced by incorporating rubber and slag aggregates in various dosages (i.e., 5, 10, 15, 20 and 25% by stone dust weight). The result revealed that the compressive strength dropped from 71 to 43 % in the case of rubber aggregate replacement. Morphology study confirms that the rubber aggregates resulted in the porous microstructure of the bricks and leads to lesser unit weight and lighter structure. The rubber may be used as a lightweight aggregate in the brick possibly as it reduces the density of the final product. However, the use of rubber in bricks needs to be cautiously designed to get hold of productive solutions at the end. The findings demonstrate that the copper slag substitution of up to 15%, found to be enhanced the strength properties and it will be a better choice for low-cost construction as a promising alternative construction material.","PeriodicalId":54473,"journal":{"name":"Revista de la Construccion","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71304698","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The main purpose of this study is to determine the stress-strain behaviour of a rigid circular footing placed on recycled rubber tyre-reinforced granular filling built on weak soil. For this purpose, model plate loading tests were carried out on reinforced/unreinforced granular filling built with natural aggregates (NA) or construction and demolition waste materials (CDW). The rubber tyre used for reinforcement has become a waste material by completing its service life but it has retained its typical cylindrical shape. In model plate loading tests, the effects of the granular fillings, the type of fillings material and the placement of whole rubber tyre and/or geotextile in the granular fillings were investigated. Depending on the results of tests, it was determined that the bearing capacity was increased by reinforcing with the rubber tyre and/or the geotextile. Furthermore, it was specified that the highest increase in bearing capacity was occurred case of by reinforcing with the geotextile together with the rubber tyre of the granular filling. The CDW and the NA fills reinforced with geotextile together with the rubber tyre increased the bearing capacity of weak soils by 6.59 and 8.49 times, respectively, for the 5% deformation ratio. On the other hand, it was reported that although the bearing capacity of the NA was higher than that of the CDW, the bearing capacity of the reinforced CDW approached that of the NA.
{"title":"Model studies on recycled whole rubber tyre reinforced granular fillings on weak soil","authors":"T. Geçkil, Talha Sarıcı, Bahadir Ok","doi":"10.7764/rdlc.21.2.264","DOIUrl":"https://doi.org/10.7764/rdlc.21.2.264","url":null,"abstract":"The main purpose of this study is to determine the stress-strain behaviour of a rigid circular footing placed on recycled rubber tyre-reinforced granular filling built on weak soil. For this purpose, model plate loading tests were carried out on reinforced/unreinforced granular filling built with natural aggregates (NA) or construction and demolition waste materials (CDW). The rubber tyre used for reinforcement has become a waste material by completing its service life but it has retained its typical cylindrical shape. In model plate loading tests, the effects of the granular fillings, the type of fillings material and the placement of whole rubber tyre and/or geotextile in the granular fillings were investigated. Depending on the results of tests, it was determined that the bearing capacity was increased by reinforcing with the rubber tyre and/or the geotextile. Furthermore, it was specified that the highest increase in bearing capacity was occurred case of by reinforcing with the geotextile together with the rubber tyre of the granular filling. The CDW and the NA fills reinforced with geotextile together with the rubber tyre increased the bearing capacity of weak soils by 6.59 and 8.49 times, respectively, for the 5% deformation ratio. On the other hand, it was reported that although the bearing capacity of the NA was higher than that of the CDW, the bearing capacity of the reinforced CDW approached that of the NA.","PeriodicalId":54473,"journal":{"name":"Revista de la Construccion","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71304863","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
L. Neiva, Juliane Aparecida Braz Starlino, G. Elias, Arlene Maria Cunha Sarmanho, Vinícius Nicchio Alves
Brazilian standards for design of cold-formed steel (ABNT NBR 14762:2010, 2010) and design of pallet racks (ABNT NBR 15524-2:2007, 2007) have different procedures to determine the strength of columns under axial compression, using different buckling curves. This paper aims to evaluate the efficiency of using cold-formed Brazilian standard buckling design curve instead of the formulations of the pallet-rack design standard to study the use viability of the equations in the calculation procedure for computing the uprights compressive strength. This strength was calculated in four ways: one using the original equations of pallet-rack Brazilian standard, and the other three using adaptations of the buckling curve from the cold-formed steel design standard. A theoretical and numerical procedure based on finite element analysis concerning local, global, and distortional buckling and imperfections was performed. Furthermore, experimental results were also consulted to determine the effective area of studied cross-sections considering the effects of local buckling and the presence of continuous perforations. The results show that the proposed modifications are consistently correlated to the results obtained using the original equations of ABNT NBR 15524, indicating the viability of using the buckling curve of ABNT NBR 14762.
{"title":"Industrial storage system continuous perforated uprights: a combined design proposal","authors":"L. Neiva, Juliane Aparecida Braz Starlino, G. Elias, Arlene Maria Cunha Sarmanho, Vinícius Nicchio Alves","doi":"10.7764/rdlc.21.2.204","DOIUrl":"https://doi.org/10.7764/rdlc.21.2.204","url":null,"abstract":"Brazilian standards for design of cold-formed steel (ABNT NBR 14762:2010, 2010) and design of pallet racks (ABNT NBR 15524-2:2007, 2007) have different procedures to determine the strength of columns under axial compression, using different buckling curves. This paper aims to evaluate the efficiency of using cold-formed Brazilian standard buckling design curve instead of the formulations of the pallet-rack design standard to study the use viability of the equations in the calculation procedure for computing the uprights compressive strength. This strength was calculated in four ways: one using the original equations of pallet-rack Brazilian standard, and the other three using adaptations of the buckling curve from the cold-formed steel design standard. A theoretical and numerical procedure based on finite element analysis concerning local, global, and distortional buckling and imperfections was performed. Furthermore, experimental results were also consulted to determine the effective area of studied cross-sections considering the effects of local buckling and the presence of continuous perforations. The results show that the proposed modifications are consistently correlated to the results obtained using the original equations of ABNT NBR 15524, indicating the viability of using the buckling curve of ABNT NBR 14762.","PeriodicalId":54473,"journal":{"name":"Revista de la Construccion","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71304979","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Construction work is one of the most dangerous business lines. As a result of occupational accidents in construction works, there are consequences that will affect human life such as injury and death, as well as serious financial losses. Especially in developing countries, despite the increase in precautions regarding occupational safety, occupational accidents continue to occur. Human behavior is an important factor in construction work accidents. In the sector where generally low-educated level workers work, analyzing the precautions and occupational safety training results are important to reduce construction work accidents. Eye-tracking technique, a technology that is spreading around the world, finds its place in different sectors. Especially with the use of mobile eye trackers instead of fixed eye trackers, this eye-tracking technology has also become usable in site implementations in the construction industry. In the construction sector, some studies are done especially on occupational safety issues using eye-tracking techniques in recent years. In this study, a site study was done with construction workers using a mobile eye-tracking approach by creating a track with different hazard sources in construction where a fatal occupational accident occurred. In this context, the attention levels of construction workers against different sources of danger and the risk of accidents created by these sources were measured with the mobile eye-tracking technique. The results obtained from the study were shared with the occupational safety experts on the site and the results are interpreted. All workers participating in the experimental study were workers that previously got occupational safety training. Therefore, according to the outcomes of this experiment, the effectiveness of the occupational safety training they received is measured and some suggestions are made.
{"title":"Safety monitoring analysis in a construction site using eye-tracking method","authors":"Cemil Akcay","doi":"10.7764/rdlc.21.3.602","DOIUrl":"https://doi.org/10.7764/rdlc.21.3.602","url":null,"abstract":"Construction work is one of the most dangerous business lines. As a result of occupational accidents in construction works, there are consequences that will affect human life such as injury and death, as well as serious financial losses. Especially in developing countries, despite the increase in precautions regarding occupational safety, occupational accidents continue to occur. Human behavior is an important factor in construction work accidents. In the sector where generally low-educated level workers work, analyzing the precautions and occupational safety training results are important to reduce construction work accidents. Eye-tracking technique, a technology that is spreading around the world, finds its place in different sectors. Especially with the use of mobile eye trackers instead of fixed eye trackers, this eye-tracking technology has also become usable in site implementations in the construction industry. In the construction sector, some studies are done especially on occupational safety issues using eye-tracking techniques in recent years. In this study, a site study was done with construction workers using a mobile eye-tracking approach by creating a track with different hazard sources in construction where a fatal occupational accident occurred. In this context, the attention levels of construction workers against different sources of danger and the risk of accidents created by these sources were measured with the mobile eye-tracking technique. The results obtained from the study were shared with the occupational safety experts on the site and the results are interpreted. All workers participating in the experimental study were workers that previously got occupational safety training. Therefore, according to the outcomes of this experiment, the effectiveness of the occupational safety training they received is measured and some suggestions are made.","PeriodicalId":54473,"journal":{"name":"Revista de la Construccion","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71305558","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study investigates the effects of basic mix design variables such as water/cement ratio (w/c), slump flow, coarse-to-total aggregate ratio (CA/TA), and maximum aggregate size (Dmax) on the main characteristics of self-consolidating concrete. The w/c of the mixtures was either 0.42 or 0.50. The CA/TA ranged between 0.45 and 0.53. Slump flow was adjusted to 550, 650 or 720 ±20 mm by varying the superplasticizer content. Dmax was varied as 10, 15 and 20 mm. V-funnel, L-box, rheometer, sieve segregation tests and a new test method, recently developed by the authors, for dynamic segregation resistance were performed. The effect of each variable on the test results were effectively summarized in a table. Increasing the w/c, CA/TA and Dmax decreased the superplasticizer demand and increased the flowability. When the slump flow, w/c and CA/TA were higher, viscosity was found to be lower. Higher values of CA/TA and Dmax were found to reduce the passing ability. Increasing the slump flow (or superplasticizer content), CA/TA and Dmax disturbed the stability. Generally, the effects of w/c and slump flow on the SCC characteristics were more pronounced when compared to those of CA/TA and Dmax. Good correlations were obtained between several test results.
{"title":"Effects of mix-design variables on the workability, rheology and stability of self-consolidating concrete","authors":"Mohammad Musa Alami","doi":"10.7764/rdlc.21.3.703","DOIUrl":"https://doi.org/10.7764/rdlc.21.3.703","url":null,"abstract":"This study investigates the effects of basic mix design variables such as water/cement ratio (w/c), slump flow, coarse-to-total aggregate ratio (CA/TA), and maximum aggregate size (Dmax) on the main characteristics of self-consolidating concrete. The w/c of the mixtures was either 0.42 or 0.50. The CA/TA ranged between 0.45 and 0.53. Slump flow was adjusted to 550, 650 or 720 ±20 mm by varying the superplasticizer content. Dmax was varied as 10, 15 and 20 mm. V-funnel, L-box, rheometer, sieve segregation tests and a new test method, recently developed by the authors, for dynamic segregation resistance were performed. The effect of each variable on the test results were effectively summarized in a table. Increasing the w/c, CA/TA and Dmax decreased the superplasticizer demand and increased the flowability. When the slump flow, w/c and CA/TA were higher, viscosity was found to be lower. Higher values of CA/TA and Dmax were found to reduce the passing ability. Increasing the slump flow (or superplasticizer content), CA/TA and Dmax disturbed the stability. Generally, the effects of w/c and slump flow on the SCC characteristics were more pronounced when compared to those of CA/TA and Dmax. Good correlations were obtained between several test results.","PeriodicalId":54473,"journal":{"name":"Revista de la Construccion","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71306023","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In view of the past earthquakes, it is stated that several structures are located in active seismic zones around the world. So, improvement of the earthquake performance levels of the existing buildings by using various strengthening methods has been the major interest in structural engineering. Non-linear analysis procedures that are defined in several seismic codes exhibit reliable results in the evaluation of seismic performances of existing buildings. In this study, seismic performances of three, five and eight storey existing and strengthened reinforced concrete buildings having the common floor plan, material and section properties of the structural members are investigated according to Turkish Building Earthquake Code-2018 and American Standard, ASCE. To obtain the earthquake performance results of reinforced concrete buildings, displacement demands of the buildings have been obtained and utilized in nonlinear analyses. SAP2000 structural analysis software is used in the solutions. The determined strengthening techniques are provided by adding concentric steel bracing members to existing reinforced concrete buildings and jacketing of the determined columns. As a result of non-linear analyses applied to the existing and strengthened buildings, damage situations of the structural members are determined, seismic performances of the buildings are evaluated according to both codes and the results are interpreted in the end.
{"title":"Performance evaluation and strengthening of reinforced concrete buildings","authors":"R. T. Erdem, Koçali Karal","doi":"10.7764/rdlc.21.1.53","DOIUrl":"https://doi.org/10.7764/rdlc.21.1.53","url":null,"abstract":"In view of the past earthquakes, it is stated that several structures are located in active seismic zones around the world. So, improvement of the earthquake performance levels of the existing buildings by using various strengthening methods has been the major interest in structural engineering. Non-linear analysis procedures that are defined in several seismic codes exhibit reliable results in the evaluation of seismic performances of existing buildings. In this study, seismic performances of three, five and eight storey existing and strengthened reinforced concrete buildings having the common floor plan, material and section properties of the structural members are investigated according to Turkish Building Earthquake Code-2018 and American Standard, ASCE. To obtain the earthquake performance results of reinforced concrete buildings, displacement demands of the buildings have been obtained and utilized in nonlinear analyses. SAP2000 structural analysis software is used in the solutions. The determined strengthening techniques are provided by adding concentric steel bracing members to existing reinforced concrete buildings and jacketing of the determined columns. As a result of non-linear analyses applied to the existing and strengthened buildings, damage situations of the structural members are determined, seismic performances of the buildings are evaluated according to both codes and the results are interpreted in the end.","PeriodicalId":54473,"journal":{"name":"Revista de la Construccion","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71304740","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Eddie Echeverría-Maggi, V. Flores-Alés, J. J. Martín-del-Río
This work presents a sustainable panel elaboration for housing interiors through banana fiber and peanut shells gathered from crop residues, consolidated with a polyester resin binder. A material characterization process was defined by forming three prototypes with different dosages. The prototypes performed physical and mechanical tests following recommendations from previous research and the standards. The results obtained were favorable regarding thermal transmittance percentages, achieving an average resistance comparable to non-structural medium density particleboard (MDP). Performance comparisons were also established, which depict the potential of these prototypes to contribute to the building industry, including the development of thermally comfortable environments.
{"title":"Reuse of banana fiber and peanut shells for the design of new prefabricated products for buildings","authors":"Eddie Echeverría-Maggi, V. Flores-Alés, J. J. Martín-del-Río","doi":"10.7764/rdlc.21.2.461","DOIUrl":"https://doi.org/10.7764/rdlc.21.2.461","url":null,"abstract":"This work presents a sustainable panel elaboration for housing interiors through banana fiber and peanut shells gathered from crop residues, consolidated with a polyester resin binder. A material characterization process was defined by forming three prototypes with different dosages. The prototypes performed physical and mechanical tests following recommendations from previous research and the standards. The results obtained were favorable regarding thermal transmittance percentages, achieving an average resistance comparable to non-structural medium density particleboard (MDP). Performance comparisons were also established, which depict the potential of these prototypes to contribute to the building industry, including the development of thermally comfortable environments.","PeriodicalId":54473,"journal":{"name":"Revista de la Construccion","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71305095","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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