The Butterfly Optimization Algorithm (BOA) is a swarm based technique, inspired from mating and food searching process of butterflies, developed in last year. Experiments indicate that BOA provides substantial exploration capability on conventional non-constrained benchmark problems, however for the cases with more complex and noisy domains the algorithm can easily be trapped into local minima due to its restricted exploitation behavior. To tackle this issue, current study deals with introducing an alternative search strategy to explore the region of the search domain with high certainty. Such that, firstly a weighted agent is defined and then a quadratic search is performed in the vicinity of this pre-defined agent. This alternative search strategy is named as Enhanced Quadratic Approximation (EQA) and it is combined with BOA method to improve its exploitation behavior and provide an efficient search algorithm. Thus, obtained new method is named as Enhanced Quadratic Approximation Integrated with Butterfly Optimization (EQB) algorithm. Different properties of proposed EQB are tested on mathematical and structural benchmark problems. Acquired results show that the introduced algorithm, in comparison with its parent method and some other well-stablished reported algorithms in the literature, provides a competitive performance in terms of stability, accuracy and convergence rate.
{"title":"Enhanced quadratic approximation integrated with butterfly optimization: a new search algorithm tested on structural and mathematical problems","authors":"A. Mortazavi, S. Seker","doi":"10.7764/rdlc.20.2.215","DOIUrl":"https://doi.org/10.7764/rdlc.20.2.215","url":null,"abstract":"The Butterfly Optimization Algorithm (BOA) is a swarm based technique, inspired from mating and food searching process of butterflies, developed in last year. Experiments indicate that BOA provides substantial exploration capability on conventional non-constrained benchmark problems, however for the cases with more complex and noisy domains the algorithm can easily be trapped into local minima due to its restricted exploitation behavior. To tackle this issue, current study deals with introducing an alternative search strategy to explore the region of the search domain with high certainty. Such that, firstly a weighted agent is defined and then a quadratic search is performed in the vicinity of this pre-defined agent. This alternative search strategy is named as Enhanced Quadratic Approximation (EQA) and it is combined with BOA method to improve its exploitation behavior and provide an efficient search algorithm. Thus, obtained new method is named as Enhanced Quadratic Approximation Integrated with Butterfly Optimization (EQB) algorithm. Different properties of proposed EQB are tested on mathematical and structural benchmark problems. Acquired results show that the introduced algorithm, in comparison with its parent method and some other well-stablished reported algorithms in the literature, provides a competitive performance in terms of stability, accuracy and convergence rate.","PeriodicalId":54473,"journal":{"name":"Revista de la Construccion","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2021-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43307790","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}
Hojjat Hosseinnezhad, Daniel Hatungimana, Ş. Yazici
The compressive strength, splitting tensile strength, pulse velocity, and drop weight impact resistance of roller-compacted concrete (RCC) mixtures containing recycled concrete aggregate (RCA) were investigated. The cement contents of the RCC mixtures were chosen as 150, 200 and 250 kg/m3. In addition to the control mixtures containing no RCA, 25, 50, 75, and 100 wt% of the crushed limestone aggregate was replaced with RCA. In this way, 15 RCC mixtures were prepared. The water content of RCC mixtures was determined by the maximum density method. The results showed that increasing the amount of recycled aggregate decreased the mechanical properties of the concrete. However, up to 25% replacement level, recycled aggregate had not a significant detrimental effect on the properties of RCC. Besides, the detrimental effect of RCA substitution was more pronounced in leaner mixtures and reduced by increasing the cement content of the RCC.
{"title":"Mechanical properties of roller compacted concrete containing recycled concrete aggregate","authors":"Hojjat Hosseinnezhad, Daniel Hatungimana, Ş. Yazici","doi":"10.7764/rdlc.20.2.277","DOIUrl":"https://doi.org/10.7764/rdlc.20.2.277","url":null,"abstract":"The compressive strength, splitting tensile strength, pulse velocity, and drop weight impact resistance of roller-compacted concrete (RCC) mixtures containing recycled concrete aggregate (RCA) were investigated. The cement contents of the RCC mixtures were chosen as 150, 200 and 250 kg/m3. In addition to the control mixtures containing no RCA, 25, 50, 75, and 100 wt% of the crushed limestone aggregate was replaced with RCA. In this way, 15 RCC mixtures were prepared. The water content of RCC mixtures was determined by the maximum density method. The results showed that increasing the amount of recycled aggregate decreased the mechanical properties of the concrete. However, up to 25% replacement level, recycled aggregate had not a significant detrimental effect on the properties of RCC. Besides, the detrimental effect of RCA substitution was more pronounced in leaner mixtures and reduced by increasing the cement content of the RCC.","PeriodicalId":54473,"journal":{"name":"Revista de la Construccion","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2021-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43758875","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}
Machinery has been used in the construction industry in both small and large scale projects for a long time. Machinery is one of the main components of any construction projects and rates deviation within the hiring of the machinery can result in cost overrun of the project. To deal with the issue of deviating the machinery hire rates in the construction industry, this study has been conducted. The study accesses the machinery hire rates and aims to investigate the percentage deviation from 2013 to 2018, where statistical analysis was performed to identify the influence of the inflation rate in deviating the machinery hire which results in cost overrun. The analysis shows that the inflation rate possesses a weak relationship with nine of the machinery hire rates, where five shows a moderate relationship. It is therefore recommended to observe other factors which deviate the machinery hire rates within the construction industry.
{"title":"Construction machinery hire rates deviation in Malaysia: an inflation rate effect analysis","authors":"M. A. Musarat, W. Alaloul, M. S. Liew","doi":"10.7764/RDLC.20.1.91","DOIUrl":"https://doi.org/10.7764/RDLC.20.1.91","url":null,"abstract":"Machinery has been used in the construction industry in both small and large scale projects for a long time. Machinery is one of the main components of any construction projects and rates deviation within the hiring of the machinery can result in cost overrun of the project. To deal with the issue of deviating the machinery hire rates in the construction industry, this study has been conducted. The study accesses the machinery hire rates and aims to investigate the percentage deviation from 2013 to 2018, where statistical analysis was performed to identify the influence of the inflation rate in deviating the machinery hire which results in cost overrun. The analysis shows that the inflation rate possesses a weak relationship with nine of the machinery hire rates, where five shows a moderate relationship. It is therefore recommended to observe other factors which deviate the machinery hire rates within the construction industry.","PeriodicalId":54473,"journal":{"name":"Revista de la Construccion","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2021-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41983340","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}
Earthquake negatively affects the behavior of reinforced concrete frame systems that have slab discontinuities. As a result of differences in diaphragm behavior according to slab void ratio and position, lateral loads cannot be distributed to vertical bearing elements in proportion to their rigidity. In this study, the topic of differences in the behavior of reinforced concrete frame system under lateral load if void ratio and position of the slab change have been examined numerically. For this purpose, five single-story three-dimensional carrier frame models with different void ratios and positions were created in the ANSYS program analyzing according to the finite element method. As a result of the study, an increase in slab void ratio of reinforced concrete frame type carrier systems resulted in displacement in more significant amounts. Along with 25% being a safe void ratio in terms of rigid diaphragm behavior when the void ratio is 50%, whether the void is symmetrical or not becomes extremely important in terms of behavior.
{"title":"Numerical investigation of the effect of beam slab openings in RC structures on seismic behavior","authors":"Ahmet Özbayrak, F. Altun","doi":"10.7764/rdlc.20.3.512","DOIUrl":"https://doi.org/10.7764/rdlc.20.3.512","url":null,"abstract":"Earthquake negatively affects the behavior of reinforced concrete frame systems that have slab discontinuities. As a result of differences in diaphragm behavior according to slab void ratio and position, lateral loads cannot be distributed to vertical bearing elements in proportion to their rigidity. In this study, the topic of differences in the behavior of reinforced concrete frame system under lateral load if void ratio and position of the slab change have been examined numerically. For this purpose, five single-story three-dimensional carrier frame models with different void ratios and positions were created in the ANSYS program analyzing according to the finite element method. As a result of the study, an increase in slab void ratio of reinforced concrete frame type carrier systems resulted in displacement in more significant amounts. Along with 25% being a safe void ratio in terms of rigid diaphragm behavior when the void ratio is 50%, whether the void is symmetrical or not becomes extremely important in terms of behavior.","PeriodicalId":54473,"journal":{"name":"Revista de la Construccion","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71304527","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}
Earthquakes’ effects on the ground especially to superstructures vary depending on the local site conditions. As the seismic waves move towards the surface, the dynamic behavior is affected by the depth of the bedrock, layer thickness, and the soil type. Site specific soil behavior analyses are carried out to estimate the seismic force spread from the bedrock to the ground along the soil layers and to determine the spectral properties of the site. During the transmission of the wavelength, the amplitude and frequency content change depending on the properties of the soil layers. Both the alteration of the dynamic properties of soil layers and the earthquake characteristics must be analyzed in order to predict the ground surface behavior. Turkey is one of the most important earthquake prone country in Europe and it is crucial to reduce any possible damage as a result of seismicity by taking the necessary measures. This study focuses on a region near North Anatolian Fault which is one of seismically active faults in Yalova region in Turkey. The goal is to understand the nonlinear site specific behavior along with the equivalent linear option using two boring data with similar shear wave velocity and site class. Eleven different earthquakes were chosen for the analysis. The fault type and the soil class are the main characteristics to determine those records. The spectral behaviors of the ground surface were obtained from different models and they were compared with three different building codes (the new Turkish Building Code (TBC 2018), the Eurocode8 (EC8) and the International Building Code (IBC)). Analysis show that 1) the performance of the building codes vary a lot to predict the surface behavior, 2) equivalent and nonlinear site response differ in terms of short and long period spectral behavior and 3) the determination of site classes from shear wave velocity solely may not be sufficient to understand the propagation of the wave and sandy or clayey behavior should also be considered in design purposes.
{"title":"Assessment of shear wave velocity concept on the site specific analysis and its effects over performances of building codes","authors":"E. Güler, Kamil Bekir Afacan","doi":"10.7764/rdlc.20.3.527","DOIUrl":"https://doi.org/10.7764/rdlc.20.3.527","url":null,"abstract":"Earthquakes’ effects on the ground especially to superstructures vary depending on the local site conditions. As the seismic waves move towards the surface, the dynamic behavior is affected by the depth of the bedrock, layer thickness, and the soil type. Site specific soil behavior analyses are carried out to estimate the seismic force spread from the bedrock to the ground along the soil layers and to determine the spectral properties of the site. During the transmission of the wavelength, the amplitude and frequency content change depending on the properties of the soil layers. Both the alteration of the dynamic properties of soil layers and the earthquake characteristics must be analyzed in order to predict the ground surface behavior. Turkey is one of the most important earthquake prone country in Europe and it is crucial to reduce any possible damage as a result of seismicity by taking the necessary measures. This study focuses on a region near North Anatolian Fault which is one of seismically active faults in Yalova region in Turkey. The goal is to understand the nonlinear site specific behavior along with the equivalent linear option using two boring data with similar shear wave velocity and site class. Eleven different earthquakes were chosen for the analysis. The fault type and the soil class are the main characteristics to determine those records. The spectral behaviors of the ground surface were obtained from different models and they were compared with three different building codes (the new Turkish Building Code (TBC 2018), the Eurocode8 (EC8) and the International Building Code (IBC)). Analysis show that 1) the performance of the building codes vary a lot to predict the surface behavior, 2) equivalent and nonlinear site response differ in terms of short and long period spectral behavior and 3) the determination of site classes from shear wave velocity solely may not be sufficient to understand the propagation of the wave and sandy or clayey behavior should also be considered in design purposes.","PeriodicalId":54473,"journal":{"name":"Revista de la Construccion","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71304534","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}
Today, the use of high-density polyethylene (HDPE) transfer lines is increasing day by day for drinking water, wastewater, sewerage networks, rainwater drainage lines, water transport structures, and natural energy sources, etc. In this study, flexible HDPE pipes were embedded in a trench to expose them to variable relative density and different thermal conditions so that the resulting deformation behavior could be investigated. Displacements and elastic strain values in the crown and spring line regions were measured. The main aim of this research was to determine the behavior of HDPE pipes under temperature effects within the framework of geotechnical principles to reflect real field conditions. As a result, pipes subject to vertical loading were tested under different relative density and thermal conditions. In the experiments carried out in a silica sandy trench, the deformations increased due to an increase in relative density. The maximum displacements and bending moment values were obtained at 50°C, which was the maximum thermal condition applied. An increase in temperature increased the deformation values due to the resulting decrease in the modulus of elasticity.
{"title":"The deformation characteristics of buried HDPE transfer lines in trenches under the effect of temperature","authors":"Necmettin Polat, C. Erenson, Niyazi Uğur Terzi","doi":"10.7764/rdlc.20.3.452","DOIUrl":"https://doi.org/10.7764/rdlc.20.3.452","url":null,"abstract":"Today, the use of high-density polyethylene (HDPE) transfer lines is increasing day by day for drinking water, wastewater, sewerage networks, rainwater drainage lines, water transport structures, and natural energy sources, etc. In this study, flexible HDPE pipes were embedded in a trench to expose them to variable relative density and different thermal conditions so that the resulting deformation behavior could be investigated. Displacements and elastic strain values in the crown and spring line regions were measured. The main aim of this research was to determine the behavior of HDPE pipes under temperature effects within the framework of geotechnical principles to reflect real field conditions. As a result, pipes subject to vertical loading were tested under different relative density and thermal conditions. In the experiments carried out in a silica sandy trench, the deformations increased due to an increase in relative density. The maximum displacements and bending moment values were obtained at 50°C, which was the maximum thermal condition applied. An increase in temperature increased the deformation values due to the resulting decrease in the modulus of elasticity.","PeriodicalId":54473,"journal":{"name":"Revista de la Construccion","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71304312","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}
Verónica Fernanda Artigas, M. Positieri, Marı´a Virginia Quintana, Ángel Oshiro, Franco Rodrigo Cortez
With the increasing infrastructure and the need for eco-sustainable alternatives, the concrete industry has motivated to look for supplementary cementitious materials especially those generated from waste. The advantages of self-compacting concrete (SCC) make it useful in the worldwide; therefore, it is essential to study additions that can be incorporated into it, to improve its properties. Limestone powder (LP) and local waste perlite fines (PF) from Salta (Argentina) are proposed as mineral addition in self-compacting mortars (SCM). PF has a high content of SiO2 and Al2O3 which can contribute to increasing the strength of the concrete due to the pozzolanic reaction. Physicochemical characterization of this waste is studied and the behavior of SCM mixtures with different proportions of LP and PF are also analyzed. Sets of specimens have been performed in order to test their rheological characteristics in the fresh state and their mechanical resistance in the hardened state. The results indicate that the combination of LP and PF has a beneficial influence on the fresh state, granting an adequate fluidity and viscosity of the mixture; on the hardened state, compressive strengths similar to the standard are achieved at 90 days in mortars with up to 20% cement replacement by additions.
{"title":"Self-compacting mortars with mineral additions: perlite and limestone filler","authors":"Verónica Fernanda Artigas, M. Positieri, Marı´a Virginia Quintana, Ángel Oshiro, Franco Rodrigo Cortez","doi":"10.7764/rdlc.20.3.479","DOIUrl":"https://doi.org/10.7764/rdlc.20.3.479","url":null,"abstract":"With the increasing infrastructure and the need for eco-sustainable alternatives, the concrete industry has motivated to look for supplementary cementitious materials especially those generated from waste. The advantages of self-compacting concrete (SCC) make it useful in the worldwide; therefore, it is essential to study additions that can be incorporated into it, to improve its properties. Limestone powder (LP) and local waste perlite fines (PF) from Salta (Argentina) are proposed as mineral addition in self-compacting mortars (SCM). PF has a high content of SiO2 and Al2O3 which can contribute to increasing the strength of the concrete due to the pozzolanic reaction. Physicochemical characterization of this waste is studied and the behavior of SCM mixtures with different proportions of LP and PF are also analyzed. Sets of specimens have been performed in order to test their rheological characteristics in the fresh state and their mechanical resistance in the hardened state. The results indicate that the combination of LP and PF has a beneficial influence on the fresh state, granting an adequate fluidity and viscosity of the mixture; on the hardened state, compressive strengths similar to the standard are achieved at 90 days in mortars with up to 20% cement replacement by additions.","PeriodicalId":54473,"journal":{"name":"Revista de la Construccion","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71304358","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}
Graphene oxide (GO) is that the product of the exfoliation of graphite by chemical processes. GO has a potential candidate to be used as a nano reinforcement material in cement-based systems due to its water dispensability, quite good mechanical properties, and high aspect ratios. In this research, the effects of different water/binder (water/cement) ratio (0.55, 0.70, 0.90, and 1.00) and graphene oxide on mortars to which applied DC stress intensity have been investigated. In experiments, 4cm x 4cm x 16cm wood molds (electrical isolated) have been used. Immediately after mixing into the mixtures, a stress intensity of 25 V was applied for 24 hours with a DC power source. Experiments were conducted in the laboratory conditions. Effect on hydration internal temperatures of the mortars with direct current application has been investigated. It is also researched that, the effect of graphene oxide on hydration temperature by direct current (DC) application on mortars. Through the application of 25 V DC to the 300 dosage mortars to which have different w/c ratios (0.55, 0.70, 0.90 and 1.00), their internal temperatures are increased as 1.26 °C, 1.78 °C, 4.25, and 3.30 °C, respectively. When they are compared to the same water/cement ratio of reference samples, it has been observed that, when 0.025 % ratio of graphene oxide has been added to admixture and also direct current has applied, hydration temperature values of mortars have been increased. Microscope views have been investigated from 300 dosage mortars whose w/c ratio is 0.90 and it is determined that CSH gel formation increases as using 0.025 % GO and DC stress intensity application. It is concluded that hydration reactions can be accelerated by applying electric current to the mortar and adding graphene oxide to the mixture.
氧化石墨烯(GO)是石墨在化学过程中剥落的产物。由于氧化石墨烯的可疏水性、良好的机械性能和高纵横比，它有可能被用作水泥基体系中的纳米增强材料。在本研究中，研究了不同水/胶料(水/水泥)比(0.55、0.70、0.90和1.00)和氧化石墨烯对施加直流应力强度砂浆的影响。在实验中，使用了4cm × 4cm × 16cm的木模(电隔离)。混合后立即在直流电源上施加25 V的应力强度24小时。实验在实验室条件下进行。研究了直流电对砂浆水化内部温度的影响。研究了直流作用下氧化石墨烯对砂浆水化温度的影响。对w/c比分别为0.55、0.70、0.90和1.00的300种掺量砂浆施加25 V DC，使其内部温度分别升高1.26℃、1.78℃、4.25℃和3.30℃。将其与相同水灰比的参考样品进行比较，发现在掺合料中加入0.025%的氧化石墨烯并施加直流电时，砂浆的水化温量值有所提高。对w/c比为0.90的300种剂量砂浆进行了显微镜观察，结果表明，使用0.025%的氧化石墨烯和施加直流应力强度时，CSH凝胶形成增加。通过对砂浆施加电流并在混合物中加入氧化石墨烯，可以加速水化反应。
{"title":"Self-heating mortars with using graphene oxide and increasing CSH gel formation with the direct current application","authors":"İsmail Hocaoğlu","doi":"10.7764/rdlc.20.3.559","DOIUrl":"https://doi.org/10.7764/rdlc.20.3.559","url":null,"abstract":"Graphene oxide (GO) is that the product of the exfoliation of graphite by chemical processes. GO has a potential candidate to be used as a nano reinforcement material in cement-based systems due to its water dispensability, quite good mechanical properties, and high aspect ratios. In this research, the effects of different water/binder (water/cement) ratio (0.55, 0.70, 0.90, and 1.00) and graphene oxide on mortars to which applied DC stress intensity have been investigated. In experiments, 4cm x 4cm x 16cm wood molds (electrical isolated) have been used. Immediately after mixing into the mixtures, a stress intensity of 25 V was applied for 24 hours with a DC power source. Experiments were conducted in the laboratory conditions. Effect on hydration internal temperatures of the mortars with direct current application has been investigated. It is also researched that, the effect of graphene oxide on hydration temperature by direct current (DC) application on mortars. Through the application of 25 V DC to the 300 dosage mortars to which have different w/c ratios (0.55, 0.70, 0.90 and 1.00), their internal temperatures are increased as 1.26 °C, 1.78 °C, 4.25, and 3.30 °C, respectively. When they are compared to the same water/cement ratio of reference samples, it has been observed that, when 0.025 % ratio of graphene oxide has been added to admixture and also direct current has applied, hydration temperature values of mortars have been increased. Microscope views have been investigated from 300 dosage mortars whose w/c ratio is 0.90 and it is determined that CSH gel formation increases as using 0.025 % GO and DC stress intensity application. It is concluded that hydration reactions can be accelerated by applying electric current to the mortar and adding graphene oxide to the mixture.","PeriodicalId":54473,"journal":{"name":"Revista de la Construccion","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71304403","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 time history analysis of the linear and non-linear response of earthquake resistant structures is a tool increasingly used in practice and required by codes. In this paper, a set of 12 accelerograms was generated numerically with the spectral representation methodology. Another set of 15 accelerograms were selected from a database of earthquake records and scaled with a uniform factor so that the mean spectrum fits the design one. The non-linear dynamic response of two frames of different stiffness and resistance was obtained under the action of the two sets of accelerograms. The global force - displacement results showed a higher coefficient of variation for the set of recorded accelerograms, especially for the structure of lower resistance that has a strong non-linear incursion. The same tendency was obtained for the moment - curvature relationships of beam and column sections, with higher dispersions compared to the global results. In addition, the influence of the vertical acceleration component was analyzed, resulting in a higher incidence in the interior columns of the frames.
{"title":"Comparison of non-linear dynamic frame response under recorded and numerically generated accelerograms","authors":"O. Möller, J. P. Ascheri, Leandro Emanuel Nardi","doi":"10.7764/rdlc.20.3.576","DOIUrl":"https://doi.org/10.7764/rdlc.20.3.576","url":null,"abstract":"The time history analysis of the linear and non-linear response of earthquake resistant structures is a tool increasingly used in practice and required by codes. In this paper, a set of 12 accelerograms was generated numerically with the spectral representation methodology. Another set of 15 accelerograms were selected from a database of earthquake records and scaled with a uniform factor so that the mean spectrum fits the design one. The non-linear dynamic response of two frames of different stiffness and resistance was obtained under the action of the two sets of accelerograms. The global force - displacement results showed a higher coefficient of variation for the set of recorded accelerograms, especially for the structure of lower resistance that has a strong non-linear incursion. The same tendency was obtained for the moment - curvature relationships of beam and column sections, with higher dispersions compared to the global results. In addition, the influence of the vertical acceleration component was analyzed, resulting in a higher incidence in the interior columns of the frames.","PeriodicalId":54473,"journal":{"name":"Revista de la Construccion","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71304411","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 this study, the recycling of pipe waste powder in concrete has been experimentally investigated to reduce its harm to the environment and human health. Glass fiber reinforced polymer pipe waste powder (GFRP-WP) reveals during the production of additional coupling and bends of GFRP pipes produced for clean water and wastewater systems. GFRP-WP is composed of polyester resin, sand, and E-glass fiber. GFRP-WP was used as a partial replacement to fine aggregate in proportions of 0% 5%, 10%, 20%, 30% and 40% to the concrete mixture. The effect of GFRP-WP was examined on the physical and mechanical properties of concrete, such as compressive strength, workability, capillarity, and water absorption. According to the results, it was seen that GFRP-WP could be used as filler in concrete, and some positive and negative effects on concrete were also determined. GFRP-WP reduced the workability of concrete. Therefore, GFRP-WP impaired the properties of the concrete if certain mixing ratios were exceeded. It was determined that GFRP-WP could be used in concrete up to 15% by volume as a partial replacement for fine aggregate.
{"title":"Effects of glass fiber reinforced polymer pipe waste powder usage on concrete properties","authors":"A. Saribiyik, G. Gurbuz","doi":"10.7764/rdlc.20.3.463","DOIUrl":"https://doi.org/10.7764/rdlc.20.3.463","url":null,"abstract":"In this study, the recycling of pipe waste powder in concrete has been experimentally investigated to reduce its harm to the environment and human health. Glass fiber reinforced polymer pipe waste powder (GFRP-WP) reveals during the production of additional coupling and bends of GFRP pipes produced for clean water and wastewater systems. GFRP-WP is composed of polyester resin, sand, and E-glass fiber. GFRP-WP was used as a partial replacement to fine aggregate in proportions of 0% 5%, 10%, 20%, 30% and 40% to the concrete mixture. The effect of GFRP-WP was examined on the physical and mechanical properties of concrete, such as compressive strength, workability, capillarity, and water absorption. According to the results, it was seen that GFRP-WP could be used as filler in concrete, and some positive and negative effects on concrete were also determined. GFRP-WP reduced the workability of concrete. Therefore, GFRP-WP impaired the properties of the concrete if certain mixing ratios were exceeded. It was determined that GFRP-WP could be used in concrete up to 15% by volume as a partial replacement for fine aggregate.","PeriodicalId":54473,"journal":{"name":"Revista de la Construccion","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71304350","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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