Dian Eksana Wibowo, Dymas Agung Ramadhan, Endaryanta ., H. Prayuda
This study employs rice husk ash and pozzolan cement as additional soil stabilization materials. This study aims to evaluate the bearing capacity of the soil to be used as embankment soil for subgrade pavement materials. The soil samples were collected from two different areas in the Yogyakarta region, Indonesia, namely the Wates and Imogiri regions. This study consists of experimental approach that defines a soil embankment for road subgrade with a trapezoid-shaped with top dimension of 10 cm x 20 cm, a base dimension of (20 cm x 40 cm), and a height of 10 cm. In addition, the specimens in this study were divided into two groups: the embankment with a 1 cm-thick sand base and the embankment without a sand base. The USCS classified the samples from Wates as OH-type or organic clays with moderate to high plasticity and by AASTHO as group of A-7-5 (22). The soil from Imogiri was categorized as inorganic silt or fine diatoms sand with OH clumps or AASTHO classified this soil as group A-7-5 (11). The addition of rice husk ash and pozzolan cement as stabilizing soil materials has a moderate effect on the engineering properties of the soil, particularly the bearing capacity and bearing capacity ratio of soil. This soil stabilization also demonstrates that the engineering properties of the stabilized soil significantly improved compared to the original soil without stabilization.
{"title":"Soil stabilization using rice husk ash and cement for pavement subgrade materials","authors":"Dian Eksana Wibowo, Dymas Agung Ramadhan, Endaryanta ., H. Prayuda","doi":"10.7764/rdlc.22.1.192","DOIUrl":"https://doi.org/10.7764/rdlc.22.1.192","url":null,"abstract":"This study employs rice husk ash and pozzolan cement as additional soil stabilization materials. This study aims to evaluate the bearing capacity of the soil to be used as embankment soil for subgrade pavement materials. The soil samples were collected from two different areas in the Yogyakarta region, Indonesia, namely the Wates and Imogiri regions. This study consists of experimental approach that defines a soil embankment for road subgrade with a trapezoid-shaped with top dimension of 10 cm x 20 cm, a base dimension of (20 cm x 40 cm), and a height of 10 cm. In addition, the specimens in this study were divided into two groups: the embankment with a 1 cm-thick sand base and the embankment without a sand base. The USCS classified the samples from Wates as OH-type or organic clays with moderate to high plasticity and by AASTHO as group of A-7-5 (22). The soil from Imogiri was categorized as inorganic silt or fine diatoms sand with OH clumps or AASTHO classified this soil as group A-7-5 (11). The addition of rice husk ash and pozzolan cement as stabilizing soil materials has a moderate effect on the engineering properties of the soil, particularly the bearing capacity and bearing capacity ratio of soil. This soil stabilization also demonstrates that the engineering properties of the stabilized soil significantly improved compared to the original soil without stabilization.","PeriodicalId":54473,"journal":{"name":"Revista de la Construccion","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71305759","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}
B. Peceño, E. Pérez-Soriano, J. Ríos, Yolanda Luna, H. Cifuentes, C. Leiva
In this study, biomass ashes from different energy valorization processes and storage conditions were used to make fire-resistant materials. Some of the ashes were subjected to a carbonation process. An 80/20 ash/gypsum ratio was used in all compositions. The density and different mechanical properties (compressive and flexural strength, superficial hardness, and dynamic modulus of elasticity), as well as fire resistance properties (insulating capacity and heat absorption capacity), were evaluated at 28 days. The energy valorization had a great influence on the particle size and the Loss On Ignition (LOI) of the fly ash. By increasing both, materials with lower mechanical properties (90%) were produced. Fire resistance was similar for the different ashes tested, but 50% lower than the gypsum material. When the ashes of the materials were carbonated, the material increases compressive strength by 400% compared to ashes without the carbonation process, and the fire resistance was similar to those materials composed exclusively of gypsum, but also a source of CO2 capture is produced.
{"title":"Effect of different ashes from biomass olive pomace on the mechanical and fire properties of gypsum-based materials","authors":"B. Peceño, E. Pérez-Soriano, J. Ríos, Yolanda Luna, H. Cifuentes, C. Leiva","doi":"10.7764/rdlc.22.1.122","DOIUrl":"https://doi.org/10.7764/rdlc.22.1.122","url":null,"abstract":"In this study, biomass ashes from different energy valorization processes and storage conditions were used to make fire-resistant materials. Some of the ashes were subjected to a carbonation process. An 80/20 ash/gypsum ratio was used in all compositions. The density and different mechanical properties (compressive and flexural strength, superficial hardness, and dynamic modulus of elasticity), as well as fire resistance properties (insulating capacity and heat absorption capacity), were evaluated at 28 days. The energy valorization had a great influence on the particle size and the Loss On Ignition (LOI) of the fly ash. By increasing both, materials with lower mechanical properties (90%) were produced. Fire resistance was similar for the different ashes tested, but 50% lower than the gypsum material. When the ashes of the materials were carbonated, the material increases compressive strength by 400% compared to ashes without the carbonation process, and the fire resistance was similar to those materials composed exclusively of gypsum, but also a source of CO2 capture is produced.","PeriodicalId":54473,"journal":{"name":"Revista de la Construccion","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71305578","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}
R. Hameed, Maryam Imran, M. Hassan, K. ., Eman Arshad
Urbanization and modern development of expanding infrastructure have resulted in large construction activities. With the expeditious growth in the construction industry, the rate of demolition has also increased. This is causing considerable increase in Construction and Demolition (C&D) waste all around the globe. To minimize its impact on society and environment, preventive measures are required to be taken on urgent basis, and for this reason construction industry has proposed the use of recycle concrete aggregates in different applications and there is dire need to investigate experimentally the properties of concrete products made using Recycled Aggregate Concrete (RAC). In this regard, this study focused to investigate the mechanical properties of 100% RAC bricks prepared with two different compositions with respect to coarse to fine aggregates ratio (i.e., 70:30 and 60:40), cement dosage (i.e., 10% and 15% by weight of total aggregates) and casting pressure (i.e., 25 MPa and 35 MPa). Recycled concrete aggregates required for this study were produced by crushing tested concrete samples having compressive strength of 21 MPa to 28 MPa. Mechanical tests were performed on bricks to determine their compressive strength, flexural strength, shear strength, impact energy in compression and flexure. In addition to these destructive tests, non-destructive (rebound hammer and ultra-sonic pulse velocity) tests were also performed. To draft a comparison, Natural Aggregate Concrete (NAC) bricks and first class burnt clay bricks were also tested. The results indicated that the compressive strength of NAC bricks was about 30% higher than the compressive strength of RAC bricks. However, RAC bricks exhibited higher compressive strength as compared to burnt-clay bricks. The flexural strength of RAC bricks containing 60% coarse aggregates and 40% fine aggregates and RAC bricks containing 70% coarse aggregates and 30% fine aggregates was found to be almost similar but their flexure strength was 37.3% and 20.7% lesser than their corresponding NAC bricks. Flexure strength of RAC bricks and burnt clay bricks was found to be almost same. Qualitative assessment by ultrasonic pulse velocity (UPV) tests showed that the NAC and RAC bricks were of good quality as per the standard criteria. The findings of this study indicated that RAC bricks satisfied the strength requirements as stated by local and international standards. Further, RAC bricks performed better than commonly used first class burnt clay bricks. Production and use of RAC bricks in masonry structures will not only help to conserve the depleting resources of natural aggregates and clay but also help to protect our environment from pollution by reducing CO2 emission caused by the coal-burning as fuel in kilns for the manufacturing of burnt-clay bricks.
{"title":"Mechanical performance of 100% recycled aggregate concrete (RAC) bricks","authors":"R. Hameed, Maryam Imran, M. Hassan, K. ., Eman Arshad","doi":"10.7764/rdlc.22.1.203","DOIUrl":"https://doi.org/10.7764/rdlc.22.1.203","url":null,"abstract":"Urbanization and modern development of expanding infrastructure have resulted in large construction activities. With the expeditious growth in the construction industry, the rate of demolition has also increased. This is causing considerable increase in Construction and Demolition (C&D) waste all around the globe. To minimize its impact on society and environment, preventive measures are required to be taken on urgent basis, and for this reason construction industry has proposed the use of recycle concrete aggregates in different applications and there is dire need to investigate experimentally the properties of concrete products made using Recycled Aggregate Concrete (RAC). In this regard, this study focused to investigate the mechanical properties of 100% RAC bricks prepared with two different compositions with respect to coarse to fine aggregates ratio (i.e., 70:30 and 60:40), cement dosage (i.e., 10% and 15% by weight of total aggregates) and casting pressure (i.e., 25 MPa and 35 MPa). Recycled concrete aggregates required for this study were produced by crushing tested concrete samples having compressive strength of 21 MPa to 28 MPa. Mechanical tests were performed on bricks to determine their compressive strength, flexural strength, shear strength, impact energy in compression and flexure. In addition to these destructive tests, non-destructive (rebound hammer and ultra-sonic pulse velocity) tests were also performed. To draft a comparison, Natural Aggregate Concrete (NAC) bricks and first class burnt clay bricks were also tested. The results indicated that the compressive strength of NAC bricks was about 30% higher than the compressive strength of RAC bricks. However, RAC bricks exhibited higher compressive strength as compared to burnt-clay bricks. The flexural strength of RAC bricks containing 60% coarse aggregates and 40% fine aggregates and RAC bricks containing 70% coarse aggregates and 30% fine aggregates was found to be almost similar but their flexure strength was 37.3% and 20.7% lesser than their corresponding NAC bricks. Flexure strength of RAC bricks and burnt clay bricks was found to be almost same. Qualitative assessment by ultrasonic pulse velocity (UPV) tests showed that the NAC and RAC bricks were of good quality as per the standard criteria. The findings of this study indicated that RAC bricks satisfied the strength requirements as stated by local and international standards. Further, RAC bricks performed better than commonly used first class burnt clay bricks. Production and use of RAC bricks in masonry structures will not only help to conserve the depleting resources of natural aggregates and clay but also help to protect our environment from pollution by reducing CO2 emission caused by the coal-burning as fuel in kilns for the manufacturing of burnt-clay bricks.","PeriodicalId":54473,"journal":{"name":"Revista de la Construccion","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71306152","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}
F. Aydın, M. Akyürek, Şeymanur Arslan, Kemalettin Yılmaz
While Fibre-Reinforced Plastics are lightweight, show a high tensile strength, and have no issue with corrosion, they are unfortunately brittle and perform poorly against temperature. Therefore, it is important to know the time and magnitude of the temperature reaching the bars in the high-temperature effect of FRPs produced in the form of bar in reinforced concrete structural elements in concrete. This study set out to examine the time and temperature values of glass fiber reinforced polymer (GFRP) reinforced concrete under high-temperatures. The effects of concrete cover thickness and concrete strength on temperature transfer were researched experimentally. GFRP bars were placed in specimens prepared in three concrete strengths and three different concrete cover thicknesses (20-40-60 mm) exposed to temperature, and temperature-time graphs were created by measuring bar temperature, concrete surface temperature and ambient temperature. The critical time to a glass transition temperature, and optimum cover thickness of GFRPs according to concrete strength and concrete cover thickness were discussed. The study results appeared to indicate that the thickness of the concrete cover is very effective in protecting the bar against temperature in reinforced concrete structural elements, as concrete strength, itself, has only a limited effect.
{"title":"Effects of concrete cover thickness and concrete strength on temperature transfer in high temperature exposed FRP reinforced concrete","authors":"F. Aydın, M. Akyürek, Şeymanur Arslan, Kemalettin Yılmaz","doi":"10.7764/rdlc.22.1.242","DOIUrl":"https://doi.org/10.7764/rdlc.22.1.242","url":null,"abstract":"While Fibre-Reinforced Plastics are lightweight, show a high tensile strength, and have no issue with corrosion, they are unfortunately brittle and perform poorly against temperature. Therefore, it is important to know the time and magnitude of the temperature reaching the bars in the high-temperature effect of FRPs produced in the form of bar in reinforced concrete structural elements in concrete. This study set out to examine the time and temperature values of glass fiber reinforced polymer (GFRP) reinforced concrete under high-temperatures. The effects of concrete cover thickness and concrete strength on temperature transfer were researched experimentally. GFRP bars were placed in specimens prepared in three concrete strengths and three different concrete cover thicknesses (20-40-60 mm) exposed to temperature, and temperature-time graphs were created by measuring bar temperature, concrete surface temperature and ambient temperature. The critical time to a glass transition temperature, and optimum cover thickness of GFRPs according to concrete strength and concrete cover thickness were discussed. The study results appeared to indicate that the thickness of the concrete cover is very effective in protecting the bar against temperature in reinforced concrete structural elements, as concrete strength, itself, has only a limited effect.","PeriodicalId":54473,"journal":{"name":"Revista de la Construccion","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71306211","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}
A. M. Alawag, W. Alaloul, M. S. Liew, M. A. Musarat, A. O. Baarimah
Total Quality Management could be defined as a transformation in management style aimed at constantly increasing customer satisfaction via the design and improvement of organizational systems and processes. It is critical to use an industrialized building system to increase project successful implementation. Awareness of TQM advantages and its application could greatly improve project efficiency and performance. A literature search on TQM was done to determine the TQM implementation present state and level of awareness in IBS construction projects. The purpose of this study is to identify the current TQM implementation status in IBS projects and determine its level of awareness and potential benefits from the Malaysian construction stakeholders’ perception. A mixed approach was applied in this research with the participation of consultants, contractors, clients, and academicians from various construction industry public and private sectors in Malaysia. The questionnaire survey was used to conduct the study. A total of 371 questionnaires were collected, for a sample size of 265. The findings indicated that most construction organizations are unaware of the TQM approach. The Cronbach's Alpha coefficient achieved from the study was (0.934), indicating that the questionnaire was reliable. The statistical analysis revealed that increased efficiency, improved customer satisfaction, enhanced teamwork, increased profitability, and improved safety are the most essential TQM benefits that concerned the participants. Furthermore, the results of this study provide IBS construction practitioners with significant awareness of the components that empower TQM implementation in the construction sector. This study contributes to the understanding of TQM and project performance by demonstrating their capacity to enhance the Malaysian construction sector. Additionally, it was found that the Malaysian construction industry has not achieved a high level of quality implementation programs.
{"title":"Implementation of total quality management (TQM) in malaysian industrialized building system (IBS) projects","authors":"A. M. Alawag, W. Alaloul, M. S. Liew, M. A. Musarat, A. O. Baarimah","doi":"10.7764/rdlc.22.1.74","DOIUrl":"https://doi.org/10.7764/rdlc.22.1.74","url":null,"abstract":"Total Quality Management could be defined as a transformation in management style aimed at constantly increasing customer satisfaction via the design and improvement of organizational systems and processes. It is critical to use an industrialized building system to increase project successful implementation. Awareness of TQM advantages and its application could greatly improve project efficiency and performance. A literature search on TQM was done to determine the TQM implementation present state and level of awareness in IBS construction projects. The purpose of this study is to identify the current TQM implementation status in IBS projects and determine its level of awareness and potential benefits from the Malaysian construction stakeholders’ perception. A mixed approach was applied in this research with the participation of consultants, contractors, clients, and academicians from various construction industry public and private sectors in Malaysia. The questionnaire survey was used to conduct the study. A total of 371 questionnaires were collected, for a sample size of 265. The findings indicated that most construction organizations are unaware of the TQM approach. The Cronbach's Alpha coefficient achieved from the study was (0.934), indicating that the questionnaire was reliable. The statistical analysis revealed that increased efficiency, improved customer satisfaction, enhanced teamwork, increased profitability, and improved safety are the most essential TQM benefits that concerned the participants. Furthermore, the results of this study provide IBS construction practitioners with significant awareness of the components that empower TQM implementation in the construction sector. This study contributes to the understanding of TQM and project performance by demonstrating their capacity to enhance the Malaysian construction sector. Additionally, it was found that the Malaysian construction industry has not achieved a high level of quality implementation programs.","PeriodicalId":54473,"journal":{"name":"Revista de la Construccion","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71306292","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}
Owning a house is one of the most important decisions that low and middle income people make in their lives. The real estate market is a significant factor of the national economy as much as it is important for individuals. Therefore, predicting real estate values or real estate valuation is beneficial and necessary not only for buyers, but also for real estate agents, economists and policy makers. This issue represents an active area of research, as individuals, companies and governments hold considerable assets in real estate. In this context, the aim of the study is to predict real estate prices with Machine Learning methods using the real estate sales data set in June and July 2021 belonging to the province of Ankara. In particular, it is to perform a comprehensive comparison on Machine Learning regression types methods that give successful prediction results in various but similar tasks, which are not included in the real estate literature. Real estate data obtained over the Internet was first included in a detailed data preprocessing process, and then Linear, Lasso and Ridge Regression, XGBoost and Artificial Neural Networks (ANN) methods were used on this dataset. According to empirical findings, XGBoost and ANNs appear as very important alternatives in predicting real estate sales prices.
{"title":"Machine learning methods for prediction real estate sales prices in Turkey","authors":"C. Çilgin, Hadi Gökçen","doi":"10.7764/rdlc.22.1.163","DOIUrl":"https://doi.org/10.7764/rdlc.22.1.163","url":null,"abstract":"Owning a house is one of the most important decisions that low and middle income people make in their lives. The real estate market is a significant factor of the national economy as much as it is important for individuals. Therefore, predicting real estate values or real estate valuation is beneficial and necessary not only for buyers, but also for real estate agents, economists and policy makers. This issue represents an active area of research, as individuals, companies and governments hold considerable assets in real estate. In this context, the aim of the study is to predict real estate prices with Machine Learning methods using the real estate sales data set in June and July 2021 belonging to the province of Ankara. In particular, it is to perform a comprehensive comparison on Machine Learning regression types methods that give successful prediction results in various but similar tasks, which are not included in the real estate literature. Real estate data obtained over the Internet was first included in a detailed data preprocessing process, and then Linear, Lasso and Ridge Regression, XGBoost and Artificial Neural Networks (ANN) methods were used on this dataset. According to empirical findings, XGBoost and ANNs appear as very important alternatives in predicting real estate sales prices.","PeriodicalId":54473,"journal":{"name":"Revista de la Construccion","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71305636","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, environmental health needs more attention than in the past. Objects consisting of plastic materials such as bottles take many years to decompose. Therefore, in the recent years, a lot of research has been done to reuse them and one of which is use in the concrete mixes. In previous research, very low percentages of these materials (between 0.5% and 1.5%) has been used as fine aggregate substitutes in the concrete and evaluations have more focused on the flexural strength. In this research, Polyethylene terephthalate (PET) as a substitute for sand and Polypropylene fibers (PP) as an additive material are used in the concrete mixes. 14 concrete beams in both reinforced and unreinforced states have been evaluated. The replacement percentage of the PET is 10, 30 and 60% and additive percentage of the PP is 0.5, 1.5 and 3% of the total weight of concrete. The dimensions of the beams have been chosen in such a way to categorized in the deep beams. So, rectangular cross-section has been considered (width = 100mm and height = 400mm). Shear strength and ductility are two important parameters that have been evaluated in this research.
{"title":"Effect of polyethylene terephthalate (PET) and polypropylene (PP) fibers on the shear behavior of RC deep beams","authors":"Ali Ramhormozy, Ehsan Kazeminezhad, S. Safakhah","doi":"10.7764/rdlc.22.1.223","DOIUrl":"https://doi.org/10.7764/rdlc.22.1.223","url":null,"abstract":"Today, environmental health needs more attention than in the past. Objects consisting of plastic materials such as bottles take many years to decompose. Therefore, in the recent years, a lot of research has been done to reuse them and one of which is use in the concrete mixes. In previous research, very low percentages of these materials (between 0.5% and 1.5%) has been used as fine aggregate substitutes in the concrete and evaluations have more focused on the flexural strength. In this research, Polyethylene terephthalate (PET) as a substitute for sand and Polypropylene fibers (PP) as an additive material are used in the concrete mixes. 14 concrete beams in both reinforced and unreinforced states have been evaluated. The replacement percentage of the PET is 10, 30 and 60% and additive percentage of the PP is 0.5, 1.5 and 3% of the total weight of concrete. The dimensions of the beams have been chosen in such a way to categorized in the deep beams. So, rectangular cross-section has been considered (width = 100mm and height = 400mm). Shear strength and ductility are two important parameters that have been evaluated in this research.","PeriodicalId":54473,"journal":{"name":"Revista de la Construccion","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71306162","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}
Guillermo Mejía, Omar Sánchez, Karen Castañeda, E. Pellicer
Delay is one of the most common and complex issues that adversely affect the performance of construction pro-jects. Although much research exists on project delay, only some studies have systematically summarized and compared the causes of delay by the project type. In addition, few studies have quantitatively combined the variability across studies and related them to the responsibilities of project stakeholders. This study conducted a meta-analysis to provide quantitative and reliable evidence on delay causes combining previous research. This study categorized the top ten causes of delay published in primary research studies, calculated the average aggregate relative important index (RII) of these causes, quantitatively summarized their impact on building and road projects using meta-analysis techniques, and linked them to stakeholder responsibility. Based on an initial 160 top ten-delay causes reported, the study aggregated them into sixteen factors and seven management areas. This research found a different prioritization of delays by project type. Overall, while "site management & technical processes" was the most critical delay factor for building projects, "external issue" was for road projects. The comparison by region shows that "skills, knowledge & experience" was the most critical factor for African studies, but "late delivery and material-equipment issues" was for Asian studies. These factors were related to project stakeholders for defining mitigation actions that led to better project performance. Finally, this study provides a first taxonomy of delays, where the previous causes reported in the literature were clustered into factors and management areas.
{"title":"Stakeholders’ issues as a source of project delays: a meta-analysis between building and road projects","authors":"Guillermo Mejía, Omar Sánchez, Karen Castañeda, E. Pellicer","doi":"10.7764/rdlc.22.1.51","DOIUrl":"https://doi.org/10.7764/rdlc.22.1.51","url":null,"abstract":"Delay is one of the most common and complex issues that adversely affect the performance of construction pro-jects. Although much research exists on project delay, only some studies have systematically summarized and compared the causes of delay by the project type. In addition, few studies have quantitatively combined the variability across studies and related them to the responsibilities of project stakeholders. This study conducted a meta-analysis to provide quantitative and reliable evidence on delay causes combining previous research. This study categorized the top ten causes of delay published in primary research studies, calculated the average aggregate relative important index (RII) of these causes, quantitatively summarized their impact on building and road projects using meta-analysis techniques, and linked them to stakeholder responsibility. Based on an initial 160 top ten-delay causes reported, the study aggregated them into sixteen factors and seven management areas. This research found a different prioritization of delays by project type. Overall, while \"site management & technical processes\" was the most critical delay factor for building projects, \"external issue\" was for road projects. The comparison by region shows that \"skills, knowledge & experience\" was the most critical factor for African studies, but \"late delivery and material-equipment issues\" was for Asian studies. These factors were related to project stakeholders for defining mitigation actions that led to better project performance. Finally, this study provides a first taxonomy of delays, where the previous causes reported in the literature were clustered into factors and management areas.","PeriodicalId":54473,"journal":{"name":"Revista de la Construccion","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71306232","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 investigated the frost resistance of concrete exposed to sulfate and acid attacks after two years. The cement content was selected as 300 kg/m3, 350 kg/m3, 400 kg/m3, 450 kg/m3, and 500 kg/m3 in this study. 100 mm cubic specimens were prepared for experiments. After the specimens were cured in the water at 20 ± 2 °C for 28 days, they were kept in the laboratory conditions at 20 ± 2 °C for 23 months+2 days. Then, these samples were subjected to freeze-thaw cycles after being exposed to 5% sodium sulfate, 5% magnesium sulfate, 1% sulfuric acid, and 2% sulfuric acid for four days. Thus, the samples were exposed to the four different combined attacks. Lastly, the mechanical properties, weight change, and relative dynamic modulus of elasticity of these specimens were determined. Furthermore, the SEM and EDS analyses were carried out on samples. This study found that the highest compressive strength, the highest ultrasonic pulse velocity, and the lowest weight loss were the samples with 500 kg/m3 cement content subjected to combined freeze-thaw and 1% acid attack.
{"title":"Durability of concrete exposed to combined freeze-thaw, sulfate, and acid attacks after two years","authors":"Harun Tanyildizi","doi":"10.7764/rdlc.22.1.102","DOIUrl":"https://doi.org/10.7764/rdlc.22.1.102","url":null,"abstract":"This study investigated the frost resistance of concrete exposed to sulfate and acid attacks after two years. The cement content was selected as 300 kg/m3, 350 kg/m3, 400 kg/m3, 450 kg/m3, and 500 kg/m3 in this study. 100 mm cubic specimens were prepared for experiments. After the specimens were cured in the water at 20 ± 2 °C for 28 days, they were kept in the laboratory conditions at 20 ± 2 °C for 23 months+2 days. Then, these samples were subjected to freeze-thaw cycles after being exposed to 5% sodium sulfate, 5% magnesium sulfate, 1% sulfuric acid, and 2% sulfuric acid for four days. Thus, the samples were exposed to the four different combined attacks. Lastly, the mechanical properties, weight change, and relative dynamic modulus of elasticity of these specimens were determined. Furthermore, the SEM and EDS analyses were carried out on samples. This study found that the highest compressive strength, the highest ultrasonic pulse velocity, and the lowest weight loss were the samples with 500 kg/m3 cement content subjected to combined freeze-thaw and 1% acid attack.","PeriodicalId":54473,"journal":{"name":"Revista de la Construccion","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71305571","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 aim of this study is to comparatively evaluate the eco-efficient performance of the only two mandatory thermal regulations applied in Chile: The General Urban Planning and Construction Ordinance (OGUC), and the Atmospheric Decontamination Plans (PDA). Considering the PDA of the communes of Temuco and Padre las Casas, and the system limits of UNE-EN 15978:2012 for the "product" and "use" stages, this study covered the indicators of energy, carbon footprint, economic cost and emissions of fine particulate matter (PM2.5), on thermal envelopes of a house. Applying the PDA over the OGUC, the results indicate that: First, the contained energy increases by 12.4%, the carbon footprint by 8.1% and the economic cost by 7.8% in the stage of product; and second, it reduces the demand for heating, fuel consumption, carbon footprint, and PM2.5 emissions, by 19.4%, in the use stage. Finally, the study concludes that, for Chilean homes to improve their eco-efficient performance, an evaluation with a life cycle cost analysis (LCCA) approach, which allows analyzing their evolution over time, must be included in the mandatory thermal regulations that regulate them.
本研究的目的是比较评估智利仅有的两项强制性热法规的生态效率表现:总体城市规划和建设条例(OGUC)和大气净化计划(PDA)。考虑到Temuco和Padre las Casas社区的PDA，以及UNE-EN 15978:2012对“产品”和“使用”阶段的系统限制，本研究涵盖了房屋热围护结构上的能源、碳足迹、经济成本和细颗粒物(PM2.5)排放指标。结果表明:①产品阶段的含能提高12.4%，碳足迹提高8.1%，经济成本提高7.8%;第二，在使用阶段，它减少了19.4%的供暖需求、燃料消耗、碳足迹和PM2.5排放。最后，该研究得出结论，为了提高智利住宅的生态效率，必须将使用生命周期成本分析(LCCA)方法的评估纳入对其进行管理的强制性热法规中，该方法可以分析其随时间的演变。
{"title":"Eco-efficient analysis of thermal regulations applied to thermal envelopes of a dwelling in Chile","authors":"Aracely Rocha Rubilar, Claudia Muñoz Sanguinetti, Gerardo Salezer, Gabriel Cereceda Balic","doi":"10.7764/rdlc.22.1.147","DOIUrl":"https://doi.org/10.7764/rdlc.22.1.147","url":null,"abstract":"The aim of this study is to comparatively evaluate the eco-efficient performance of the only two mandatory thermal regulations applied in Chile: The General Urban Planning and Construction Ordinance (OGUC), and the Atmospheric Decontamination Plans (PDA). Considering the PDA of the communes of Temuco and Padre las Casas, and the system limits of UNE-EN 15978:2012 for the \"product\" and \"use\" stages, this study covered the indicators of energy, carbon footprint, economic cost and emissions of fine particulate matter (PM2.5), on thermal envelopes of a house. Applying the PDA over the OGUC, the results indicate that: First, the contained energy increases by 12.4%, the carbon footprint by 8.1% and the economic cost by 7.8% in the stage of product; and second, it reduces the demand for heating, fuel consumption, carbon footprint, and PM2.5 emissions, by 19.4%, in the use stage. Finally, the study concludes that, for Chilean homes to improve their eco-efficient performance, an evaluation with a life cycle cost analysis (LCCA) approach, which allows analyzing their evolution over time, must be included in the mandatory thermal regulations that regulate them.","PeriodicalId":54473,"journal":{"name":"Revista de la Construccion","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71305595","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：