The Open Construction & Building Technology Journal最新文献

{"title":"Experimental Investigation of Ultimate Shear Force Capacity of Glulam Reinforced with Glued-in Threaded Rods","authors":"Alireza Bahrami, Emil Blomberg, Simon Boqvist, Markus Lauridsen, Bengt Eriksson","doi":"10.2174/18748368-v17-e230418-2022-20","DOIUrl":"https://doi.org/10.2174/18748368-v17-e230418-2022-20","url":null,"abstract":"\u0000 \u0000 Glued-in threaded (GIT) rods have been considered an effective timber connection method having several advantages, such as high load-carrying capacity, great stiffness, and good fire resistance. This type of connection has widely been utilized in newly built modern timber structures and for reinforcing the existing ones.\u0000 \u0000 \u0000 \u0000 The purpose of this experimental research is to investigate how the ultimate shear force capacity (USFC) of glulam is affected if it is reinforced with GIT rods and to study the interaction between the glulam and GIT rods. The results of this research can help researchers and engineers to select a suitable method of reinforcing the glulam with GIT rods at a superior inclination angle (IA) to the fiber direction in order to achieve higher USFCs.\u0000 \u0000 \u0000 \u0000 A total of forty glulam samples were tested for failure. The experimental tests consisted of five different series of samples with eight samples in each series. Sample series 1 were unreinforced glulam. Sample series 2 and 4 were glulam reinforced with the GIT rods at two different IAs of 45° and 90° to the fiber direction, respectively. Sample series 3 and 5 were glulam reinforced in the same way as sample series 2 and 4, but they were split in the middle. The samples were tested for failure using a standard testing machine. The machine was connected to a computer that recorded all the values obtained from the tests.\u0000 \u0000 \u0000 \u0000 The results of the study were obtained as force-displacement graphs. The stiffness of the samples and interaction between the glulam and GIT rods were also calculated. The results achieved from the experimental tests of different series were compared and discussed.\u0000 \u0000 \u0000 \u0000 The experimental tests resulted in a 12.5% increase in the average USFC of sample series 2. However, the average USFC of sample series 4 was not enhanced significantly. The interaction between the glulam and GIT rods was obtained as 31.8% for the samples with reinforcing at the IA of 45° to the fiber direction and 3.8% for the samples with reinforcing at the IA of 90° to the fiber direction. Reinforcing the glulam with the GIT rods demonstrated the potential of enhancing its USFC. However, reinforcing the glulam with the GIT rods at the IA of 45° to the fiber direction was found to be superior to reinforcing the glulam with the GIT rods at the IA of 90° to the fiber direction.\u0000","PeriodicalId":272529,"journal":{"name":"The Open Construction & Building Technology Journal","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116568944","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Damage Identification in Plane Multi-storey Reinforced Concrete Frame","authors":"T. Makarios","doi":"10.2174/18748368-v17-230223-2022-18","DOIUrl":"https://doi.org/10.2174/18748368-v17-230223-2022-18","url":null,"abstract":"\u0000 \u0000 In this paper, a new method for damage detection in reinforced concrete multi-storey frames is presented.\u0000 \u0000 \u0000 \u0000 The proposed new methodology is a hybrid technique consisting of two parts. The first step involves determining the seismic pushover capacity curve of the structure, and the second step includes formulating the diagram of the instantaneous eigenfequencies of the structure in the nonlinear regime. With reference to this diagram, more details are given in the text. To estimate the equivalent target displacement defined at the top of the structure, which corresponds to the instantaneous eigenfrequencies of a structure with damage, the diagram of these eigenfrequencies is combined with the seismic pushover capacity curve of the structure. Thus, the target displacement at the top of the frame is calculated.\u0000 \u0000 \u0000 \u0000 The advantage of the proposed methodology is that using this target displacement, the final picture of the damage in the structure is estimated from the two pushover analyses, with positive and negative signs of the floor lateral forces corresponding to triangular distribution in elevation. For clarification, an example of a three-storey R/C frame is presented as a paradigm.\u0000 \u0000 \u0000 \u0000 Using the proposed methodology, the locations of damage in the structure are successfully identified, as well as the Damage Stiffness Matrix is estimated with high accuracy.\u0000","PeriodicalId":272529,"journal":{"name":"The Open Construction & Building Technology Journal","volume":"183 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121627078","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sustainable Construction Materials: Recycled Aggregate Concrete from Known Concrete Strength Debris","authors":"C. Issa, Georgio Hilal","doi":"10.2174/18748368-v17-e230221-2022-8","DOIUrl":"https://doi.org/10.2174/18748368-v17-e230221-2022-8","url":null,"abstract":"\u0000 \u0000 Landfills receive construction and demolition wastes (CDW) that are the debris generated during the construction, renovation, and demolition of buildings, roads, and bridges. CDW are resources that could be used in new construction projects, thus eliminating the need for virgin materials to be mined and processed \u0000 \u0000 \u0000 The main objective of this study is to develop a novel investigation of the mechanical behavior of concrete mix design incorporating recycled aggregate concrete (RAC) from casted concrete debris of known compressive strength while meticulously monitoring the effective water to cement ratio. \u0000 \u0000 The following four variables were monitored while performing the concrete mix design: the percentage of recycled coarse aggregates (RCA), the percentage of recycled fine aggregates (RFA), the gradation of the recycled material used, and the original compressive strength of the casted concrete debris. Investigated is the initial strength and size of the debris versus the quantity of usable recycled materials obtained. The consequence of the utilization of each variable in the final concrete mix is determined. The mechanical properties investigated are the compressive strength, flexural strength, and modulus of elasticity of concrete made with different percentages of recycled materials. \u0000 \u0000 The result of this study is achieving an optimum concrete mix design that also results in minimizing the negative impact on the environment by reducing the amount of CDW being dumped in landfills. \u0000 \u0000 The combination of both recycled coarse and recycled fine aggregates resulted in the increase of mechanical performance of the concrete while enhancing the environmental value of the final material.","PeriodicalId":272529,"journal":{"name":"The Open Construction & Building Technology Journal","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126907726","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Compressive Strength Dependency on the Effect of Temperature Variation on the Percentages of Steel Fiber in Concrete","authors":"Emiri Dafe Aniekan, Chiadighikaobi Paschal Chimeremeze, Ng’andu Prosper","doi":"10.2174/18748368-v17-e230202-2022-17","DOIUrl":"https://doi.org/10.2174/18748368-v17-e230202-2022-17","url":null,"abstract":"\u0000 \u0000 The aim of this study is to check the effectiveness of steel fiber to the compressive strength of concrete\u0000 \u0000 \u0000 \u0000 Fibers have long been used as building materials to improve the ductility, tensile, compressive, and flexural strengths of concrete. Although fibers have been known as an effective reinforcement material for concrete structures, it is also acknowledged to be a suitable alternative to reinforcement steel bars.\u0000 \u0000 \u0000 \u0000 The objective of this research is to investigate some engineering properties, compressive behavior of steel fiber reinforced concrete (SFRC) and the effect of elevated temperature of up to 1000°C on concrete.\u0000 \u0000 \u0000 \u0000 Various tests which included slump test, compressive strength test, as well as heating tests were done. The workability (slump) and thermal effects of M20 SFRC were evaluated.\u0000 \u0000 \u0000 \u0000 Based on the results obtained, it could be observed that the workability of the M20 concrete reduced with the increase in steel fiber (SF) content from 0% to 1.6% as values obtained were 80mm, 73mm, 67mm, 61mm and 55mm for SF contents of 0%, 0.4%, 0.8%, 1.2% and 1.6% respectively. These values showed medium workability of the concrete according to ASTM C-143/C-143 M-03. Also, the addition of SF to plain M20 concrete greatly improved the compressive strength 〖(f〗_c) with the concrete strength at 26.89N/mm2, 30.41N/mm2, 32.85N/mm2, 35.90N/mm2 and 39.66N/mm2 after 28 days of curing for steel fiber contents of 0%, 0.4%, 0.8%, 1.2% and 1.6% respectively. The f_c after heating the concrete mix to 1,000°C showed improved thermal resistance with 4.2N/mm2, 8.23N/mm2, 11.63N/mm2, 15.60N/mm2 and 17.20N/mm2 for SF contents of 0%, 0.4%, 0.8%, 1.2% and 1.6% respectively.\u0000 \u0000 \u0000 \u0000 Incorporation of steel fibers in the concrete mix decreased the workability of SFRC but increased its compressive strength and balling tendencies.\u0000","PeriodicalId":272529,"journal":{"name":"The Open Construction & Building Technology Journal","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126451848","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluating Risk Management Perspectives of Parties in Construction Projects Funded by Vietnam Government’s Budget","authors":"D. Hai, Nguyễn Thị Thủy","doi":"10.2174/18748368-v16-e221117-2022-11","DOIUrl":"https://doi.org/10.2174/18748368-v16-e221117-2022-11","url":null,"abstract":"\u0000 \u0000 Risks always go with the activities of construction investment projects. The impact of risks, whether large or small, affects the project results. The proper risk assessment will help managers have appropriate responses. Project parties with different roles will have different project participation goals. This can lead to a different view of risk between the parties in the project.\u0000 \u0000 \u0000 \u0000 This study will focus on examining the risk management perspectives of the parties during the project implementation phase for construction investment projects using Government’s budget capital in Vietnam.\u0000 \u0000 \u0000 \u0000 The author will use a multivariate regression model to consider the views of three main actors in the project, including the investor/project management board, the consultant, and the contractor.\u0000 \u0000 \u0000 \u0000 The views of the parties are analyzed based on the parties' assessment of the impact of risks on project results.\u0000 \u0000 \u0000 \u0000 Risks are unavoidable in construction investment projects. Project parties need to properly assess risks and develop appropriate responses.\u0000","PeriodicalId":272529,"journal":{"name":"The Open Construction & Building Technology Journal","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124146608","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Factors Affecting Construction Productivity for Steel Rebar Work in Hot Climate Country","authors":"Mohammed Aldahash, O. Alshamrani","doi":"10.2174/18748368-v16-e2206272","DOIUrl":"https://doi.org/10.2174/18748368-v16-e2206272","url":null,"abstract":"Construction industry is increasingly emphasizing productivity due to its effect on key performance indicators such as schedule, budget, and quality of work. This study aims to identify and rank the factors affecting the productivity of steel rebar work in construction projects in a hot climate. Among the activities involved in structural reinforced concrete work, fabricating and placing reinforced steel on a construction site is considered the most labor-intensive, outdoor, and time-consuming. In this paper, an intensive qualitative literature review is conducted to identify the factors affecting the productivity of steel rebar work in concrete construction. Initially, forty factors were identified from the literature affecting the productivity of steel rebar work in Saudi Arabia. Final list of thirty-seven factors was used in the questionnaire survey. The identical nature and core content of these factors are clustered and grouped into five categories: technical, labor, management, external, and financial. As part of this study, fifty contractors working in the Saudi Arabian construction industry are recruited to participate and complete a structured pilot study questionnaire. The results of the questionnaire are weighted using the pairwise comparison method and then ranked based on the Analytic Hierarchy Process technique. The analysis of the thirty-seven factors results in a top ten list of the leading factors that directly impact the productivity of steel rebar work in concrete construction projects in Saudi Arabia. These factors are (1) humidity, (2) delay of salary, (3) sandstorms, (4) payment delay by client, (5) labor's low wage, (6) lack of financial incentives, (7) labor work experience and skills, (8) completeness of drawings, (9) poor labor relations, and (10) labor absenteeism. The general trend in these studies is that the factors tend to vary from jurisdiction to jurisdiction, from one construction project to another, and are directly related to the zone or country of construction. These findings benefit stakeholders working in the concrete construction industry in Saudi Arabia, particularly project managers, project planners, cost estimators, and civil design and site engineers working on construction projects.","PeriodicalId":272529,"journal":{"name":"The Open Construction & Building Technology Journal","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129674572","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Performance assessment of Timber High-rise Buildings: Structural and Technological Considerations","authors":"G. Angelucci, Fabrizio Mollaioli, Milena Molle, Spartaco Paris","doi":"10.2174/18748368-v16-e2206270","DOIUrl":"https://doi.org/10.2174/18748368-v16-e2206270","url":null,"abstract":"\u0000 \u0000 Nowadays, a renewed momentum on the use of timber material is ensured by the development of high performing engineered wood products, which enables larger and taller structures to be built. Although the design of multi-story timber buildings is still in its early stages, the active interest shown by designers and researchers in advancing awareness and technologies in this field bodes well for the proliferation of an increasing number of tall wooden buildings.\u0000 \u0000 \u0000 \u0000 As a consequence of the difficulties with designing a nominally all-wooden tall structure, whilst utilizing its beneficial aspects, dual timber-concrete systems are considered in this work. In detail, the study aims to investigate the contribution of a reinforced concrete core coupled to timber stability systems for the effective control of lateral drifts in multi-storey buildings subjected to severe loading scenarios.\u0000 \u0000 \u0000 \u0000 The design of a 26-storey structural model, conceived by combining concrete cores with three design alternatives for the perimeter structure (namely a GLT frame, a CLT shear walled system and a GLT diagrid), provides the opportunity for discussing its lateral bearing capacities.\u0000 \u0000 \u0000 \u0000 The building models show high lateral stiffness in withstanding seismic and wind induced loads. This result is mainly attributable to the introduction of the rigid concrete core, which nearly supplies the demand for shear and bending stresses alone. Compared to a typical cross laminated core, the concrete tube results in a stiffness increment of 68% for the frame variant, 45% for the wall variant and 23% for the diagrid variant. Therefore, the serviceability requirements, both in terms of top displacements and inter-story drifts, are inherently satisfied and kept well below the prescriptive limitations.\u0000 \u0000 \u0000 \u0000 The results confirm the excellent behavior of the diagrid systems, for which any variations of the inner core have almost insignificant impact on the global building performance. In addition, previous research works suggest that the timber member sizing is mainly governed by stiffness requirements, which materialize through monitoring of the lateral sway, while member strength demands are deemed to be implicitly satisfied. The paper demonstrates that strength and stiffness demands can be of equal significance during the sizing process of dual systems.\u0000","PeriodicalId":272529,"journal":{"name":"The Open Construction & Building Technology Journal","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133622887","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Retrofit, Restoration and Preservation of Byzantine Monuments: Assessment of Natural Degradation and Evaluation of Intervention Options","authors":"M. Elliotis","doi":"10.2174/18748368-v16-e2206271","DOIUrl":"https://doi.org/10.2174/18748368-v16-e2206271","url":null,"abstract":"Monuments reflect the depth and grandeur of a great civilization developed in a certain region, during a specific period of history. They possess aesthetic, historical and functional values. Undoubtedly, they are seen as part of mankind’s cultural heritage. In particular, the ecclesiastical byzantine monuments in countries where the byzantine civilization flourished, between the 4th and the 15th centuries, such as in Greece and Cyprus, are of great importance, because they are considered as edifices that offer, through their aesthetic and archeological study, a mental upgrade and valuable knowledge of roman and byzantine building techniques. Thus, the need for periodic maintenance and restoration of such monuments is imperative. The objective of the present work is to give a general description of the basic steps of the dominant retrofit methodology which is nowadays used in Greece and Cyprus and leads to the preservation of byzantine monuments. This method is the same as in any other type of monument and goes through four stages: (i) in-situ visual investigation of the degree of wear and on-site experiments, (ii) laboratory testing of the original materials of the monument under study, (iii) installation of a wireless sensor network on a monument under study, aiming at the most efficient monitoring of local displacements, differential foundation settlements, temperature changes, local humidity concentration, salt formation, etc. and (iv) evaluation of several retrofit options and the implementation of the optimal solution, by applying a formulated grading methodology. An immediate finding of the present work is that these steps enable the creation of a suitable analytical model which can be used in runnig a software package, for the design of a complete retrofit/restoration procedure and the preparation of accurate architectural and structural drawings, which will finally be used for the implementation of the maintenance/preservation design. Undeniably, what is important is to select the optimal retrofit procedure for this type of historical buildings, something which is explained in detail in this article. The latter statement expresses the scope of the present work. Another major finding of this review research is that the above retrofit procedure has already been applied to many byzantine monuments, during the past twenty years in Greece and in Cyprus and seems to have already become the dominant method over existing practices, because it uses modern technologies and is more efficient and effective, since it is based on optimization procedures.","PeriodicalId":272529,"journal":{"name":"The Open Construction & Building Technology Journal","volume":"79 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116768786","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tall Buildings: Structural Analysis, Preliminary Design, and Assessment of New and Unconventional Systems","authors":"G. Lacidogna, Domenico Scaramozzino","doi":"10.2174/18748368-v16-e2205230","DOIUrl":"https://doi.org/10.2174/18748368-v16-e2205230","url":null,"abstract":"in modern In a world more and in which people are increasingly moving from the countryside into overcrowded megalopolises, tall buildings can be a possible solution to avoid excessive horizontal land consumption by conquering vertical space.","PeriodicalId":272529,"journal":{"name":"The Open Construction & Building Technology Journal","volume":"96 2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131208138","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Proposing Cubic-Grid System as a New Structural System for Tall Buildings","authors":"Morteza Sheikhi, Farideh Rezagholizadehomran","doi":"10.2174/18748368-v16-e2109160","DOIUrl":"https://doi.org/10.2174/18748368-v16-e2109160","url":null,"abstract":"\u0000 \u0000 Changes in the skyline of cities all over the world show that tall buildings are an interesting solution to accommodating growth more sustainably in today’s urban areas. Stability against lateral loading is the main issue for designing high-rise buildings. Diagrid systems or grid structures are one of these stable systems. For a long time, the only structural pattern used in this system was the triangular modulus (diagrid).\u0000 \u0000 \u0000 \u0000 In the present study, a new pattern for grid structures was introduced, and its performance was compared with the two previous common patterns (triangular and hexagonal). The new pattern is called the Isometric Cube grid, thanks to its particular shape. The design process was performed based on a simple stiffness criterion presented in the previous research. In order to calculate the stiffness of the structure for the new pattern, two types of existing structural nodes were distinguished, and the results were combined to determine the stiffness of the unit forming the entire grid. \u0000 \u0000 \u0000 \u0000 From the results of analysis, it was found that the optimal angles of diagonal elements were in the range of 50-65 degrees. Although the behavior of the new pattern in terms of shear stiffness was between the two previous patterns (and closer to the hexagonal pattern), the shear stiffness ratio increased from 30° to 65° for cube pattern, while for hexagrid, it decreased over the same range of angles.\u0000","PeriodicalId":272529,"journal":{"name":"The Open Construction & Building Technology Journal","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129795890","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}