BIM Structural Project Applied in A Case Study: Interoperability Analyses, Reinforcement Detailing Drawings and Quantity Take-off

Background: The Building Information Modelling (BIM) methodology has been acquiring, worldwide, a growing acceptance in all sectors of the Construction industry, and the study intends to contribute to its implementation within the structural design. The fundamental concept of BIM is based on the generation of a centralized virtual model with all information concerning different specialties. This is supported in efficient interoperability, but within the structural design, this aspect is difficult to achieve completely, as currently, the interoperability of this system is still inefficient. Introduction: This study intends to analyze the degree of interoperability verified in the development of all the processes (modelling, transposition, structural analyses and reinforcement detailing) involved in a structural design using BIM tools. Methods: A structural project concerning a study case was performed in order to identify benefits and limitations, based on the consistency analysis of the transposed data between systems, Revit and Robot, in all steps required in a BIM process. This text describes the stages of modelling, checking the suitability of the analytical model, its transference to the analysis tool in order to proceed with the structural calculations and detailing drawings and, finally, the transfer of drawings to the main BIM model. Results: The limitations verified in the last stage were partially surpassed with complementary work enabling the automatic transfer of drawings and quantities of materials. In addition, the study explores new capacities of BIM, namely, the extraction of information allowing the presentation of specific drawings and maps of the geometry of the reinforcement rods. Conclusion: This study identifies a working strategy that leads to an appropriate use of BIM software contributing to the optimization of labor in a structural office.

The Influence of the Material Properties on the Ultimate Behaviour of Aluminium H-shaped Beams

Background: In this paper, the influence of the Ramberg-Osgood exponent on the ultimate behaviour of the H-shaped (or I-shaped) aluminium beams subjected to non-uniform bending moment is investigated. Methods: In particular, the results of a wide parametric analysis recently carried out by the authors are herein exploited to point out the influence of the material properties. The flange slenderness, the flange-to-web slenderness ratio, and the non-dimensional shear length, accounting for the moment gradient, are the main non-dimensional parameters governing the ultimate resistance and the rotation capacity of H-shaped aluminium beams. Results: The influence of these parameters was investigated considering four different materials covering both low yielding-high hardening alloys and high yielding-low hardening alloys, which are characterised by significant differences in the values of the Ramberg-Osgood exponent of the stress-strain constitutive law of the material. Conclusion: Finally, empirical formulations for predicting the non-dimensional ultimate flexural strength and the plastic rotation capacity of H-section aluminium beams under moment gradient have been provided as a function of the Ramberg-Osgood exponent and all the above non-dimensional parameters.

Enhancement of Straw Bale Performance Using Gum Arabic

Background: The negative impacts of the construction industry are compelling arguments for embracing technology that contributes to carbon footprint reduction and resources conservation. Toward the achievement of objective 9 of the Sustainable Development Goals, the development of new building’s materials like straw bale has advanced in the construction industry. As demonstrated in the literature, straw bale is an eco-friendly material that presents many advantages, like its contribution towards a circular economy. However, it has low compressive strength and displays high displacement under compression load. So far, no attempt has been made in order to enhance the strength of straw bales. Objective: This study aimed to develop alternative material to straw bale using chopped straw stems mixed with a binder (gum Arabic) and determine its stress-strain characteristic. Methods: The manufacturing process of the new material involved the use of chopped straw and gum Arabic to form straw blocks. Results: Results obtained show that the compressive strength of straw block (1.25MPa) is greater than the strength of straw bale (0.02MPa). Also, the average displacement recorded during compression load on straw blocks (29mm) was 2.8 times smaller than the displacement in straw bale (80mm). In terms of shape and size, straw blocks match with conventional materials like cement or compressed block. This will facilitate their use in construction compared to straw bales that require skilled laborers for pre-compression and plastering. Conclusion: The use of gum arabic helps in holding straw stems together and forms a compact material with improved strength compared to straw bale. Performance improvement of the characteristics of load-bearing straw bale walls can be addressed by using straw blocks.

Stakeholders’ Insight on the Delay of Constructions Projects in the Makkah Region- KSA

Aims: This study aims to identify the major causes of delays in construction projects in the Makkah region of Saudi Arabia. It investigates the opinions of different stakeholders separately to ensure partiality and objectivity. Background: Saudi Arabia's construction industry is experiencing rapid expansion, with no shortage of contracts in any sector, either from housing or utilities to transport infrastructure. Public spending is driving the contracting industry forward [Oxford]. The construction industry contributed between 30% to 40% of the non-oil productive sectors at the end of each National Development Plan from 1980 to 2000. Makkah receives around two million pilgrims during the annual Hajj and more than 20 million visitors for performing Umrah (Al-Emad). Substantial public funds have been spent on construction projects to develop Makkah during recent years. Real estate, infrastructure, hospitals, and retail sectors are among those most likely to benefit. Most of these projects suffered delays and their consequences. The Saudi Ministry of Municipal and Rural Affairs (MOMRA) and the Ministry of Transportation acknowledged public construction project delays. They reported that approximately 75% of them exceeded their scheduled time. This is one of the main reasons to conduct this study. Methods: In this study, a comprehensive questionnaire has been developed, consisting of seventy-three causes of delay. The questionnaire was organized in the form of an importance scale. Respondents were asked to indicate their responses by ticking a column of the impact and frequency of each of the causes and construction delay in terms of 5 = very important, 4 = important, 3 = somewhat important, 2 = less important, and 1 = not important. A hundred fifty questionnaires were distributed by hand to the contractor, the consultant, and the owner in the Makkah region of Saudi Arabia. Ninety-seven forms were filled, received, and processed. The survey data were grouped into eight significant categories: owner, consultant designer, supervisor, contractor, material, labor, site, and external factors. A ninth group is left for the participants to add whatever they think of furtherer causes of delay. Results: The evaluation of the three separate surveys conducted on the responses of the owner, the contractors, and the consultant supervisor, show that the contractor is mainly responsible for the delay. Around 47% of the top ten delay factors fall in the contractor delay factors followed by laborers and owners. Three categories have not been mentioned in the top ten as delay category, including supervisors, materials, and external factors. Only one delay factor was found to be shared among the three-survey group, which is related to the labor category, that is, low productivity of labor. Conclusion: Three separate surveys have been conducted to investigate the delay in the construction industry in the Makkah region of Saudi Arabia. The surveys contain a questionnaire of seventy-three possible delay factors investigating the opinions of the three main stakeholders in the construction industry: the owners, the contractors, and the consultants. The evaluation of the survey impacts shows that the contractor is mainly responsible for the delay, followed by laborers and then the owners. One common delay factor was found among the three surveyed groups related to the labor category; that is, low productivity of labor. In frequency, the contractor category also occupied the highest percentage of the total delay contributors. Another common delay factor was found among the three surveyed groups, also related to the contractor category, that being the lack of risk evaluation by the contractor.

Progressive Collapse Performance of Steel Beam-to-Column Connections: Critical Review of Experimental Results

Background: The steel beam-to-column connections are vulnerable structural elements when a building loses one or more of its vertical load-carrying components due to abnormal or accidental loading conditions. After a column is destroyed by abnormal loads, the tensile axial force of the beam gradually increased, while the bending moment decreased, and the load-resistance mechanism shifts from a flexural mechanism to a catenary mechanism, with the axial force becoming the prevailing factor. Aims: This paper investigates the progressive collapse performance of steel beam-to-column connections. While undergoing large deformation, the beam-to-column connections are subjected to moment, shear, and tension in conjunction with high ductility demand. Their behavior under monotonic loading depends on the moment-axial tension interaction and greatly affects the progressive collapse resistance of the structure. This paper presents a critical review of experimental tests of different types of steel beam-column joints (flexible, rigid, and semi-rigid) under a central-column-removal scenario. Methods: The experimental results, including load-deformation relationships, failure modes, and catenary effects, are described in detail. The findings are used to evaluate the rotation capacity of different types of steel beam-to-column connections. The results are compared to the acceptance criteria specified by the main progressive collapse guidelines for several beam-to-column connection categories. Results: In simple (flexible) joints, the stiffness and strength at higher drift angles essentially depend on the tensile capacity of the connection that prevents, in some cases, the full development of the catenary mechanism. The connection depth alone does not seem to be an effective parameter to predict the rotational capacity of beam-to-column connections, since different connections with similar values of the connection depth result in very different values of the maximum rotation capacity. In fully rigid and semi-rigid connections, after the column removal, the flexural resistance controls the behavior at the preliminary phase, and the tensile force is almost zero. With increased downward displacement, the axial tensile force also increases, developing a catenary mechanism. Although the stiffness of rigid and semi-rigid connections is higher than flexible connections, both categories result in similar rotation capacity. Conclusion: In all the simple connections herein considered, the plastic rotation capacity obtained by tests was found much higher than the code recommended values that are probably too conservative. On the contrary, for one rigid and two semi-rigid connections, the values of the plastic rotation capacity obtained by tests are lower than the corresponding recommended values. Thus, the suggested acceptance criteria proved to be out of the conservative side.

Experimental Analysis of Guardrail Structures for Occupational Safety in Construction

Background: Guardrails are structures that protect workers from falling from heights at construction sites. Objective: The objective is to evaluate experimental models by applying static and impact loads to wood and steel guardrails. Methods: Brazilian and international standards were consulted to define the actions applied to guardrails, which were tested experimentally in three models of each material in a full-size prototype. Results: The experimental results indicate that the models studied could support the applied loads, and no local or global system rupture occurred. However, the displacements for the static load of 1500 N/m required by Brazilian RTP 01 for both models did not comply with Brazilian standard NBR 14718 because they had displacements above 20 mm, despite meeting other international standards for static testing and impact testing. Conclusion: From the results obtained in the experimental tests, it was possible to verify that the structures withstood the applied loads and could be used safely in civil construction works. However, the load requirements of RTP 01 are excessive, and NBR 14718 is not suitable for checking temporary guardrail structures. This demonstrates the need for the Brazilian standard to be revised to guide the dimensioning and verification of structures in order to adapt to international standards.

Client-Driven Level 2 BIM Implementation: A Case Study from the UAE

Background: Implementation of Building Information Modelling (BIM) has proven to deliver major performance improvements in Program efficiency, design quality, constructability, waste reduction, environmental performance, and capital & operational cost management of built environment projects. Yet BIM implementation in low BIM maturity markets, such as the UAE, is limited to technology applications which fail to deliver the full potential of BIM benefits to client originations. Objective: The purpose of this paper is to investigate BIM implementation from a client’s perspective and to present a case study that exhibits a level 2 BIM implementation process in a traditional procurement environment. Methods: The study has used a case study approach combined with a literature review. A critical appraisal of relevant literature is presented to highlight key issues hindering BIM implementation for client organizations, especially in developing BIM markets, such as the UAE. The research is collected using an action research approach within a case study, including project document audit, participation in project collaboration meetings and extensive communication with the project stakeholders. The case study is presented in a practice-oriented research format describing the project details, procurement approach, BIM development & management process and benefits achieved for the project client. Results: The paper presents a structured approach to strategically introduce BIM within a low BIM maturity market, creating partnering relationships, empower the supply chain partners and achieving significant BIM benefits with minimum disruption to existing work practices. The paper highlights that although BIM requires a step-change in the work practices of the construction industry, yet it is possible to successfully implement BIM with traditional procurement settings, which may be a critical feature in a certain market or a client requirement. Conclusion: There is a need for case study based, practice-oriented research work within the domain of BIM implementation. Construction clients in low maturity BIM markets are concerned about the perceived benefits of BIM and its practical implementation within existing business practices, which is addressed in this paper. Overall, the findings of this study are useful for construction industry clients and academia in redefining the existing work practices to incorporate BIM-enabled processes and applications.

Experimental Investigation of Shear Strength for Steel Fibre Reinforced Concrete Beams

Aims: The aim of this paper is to investigate the influence of the volume fraction of fibres, the depth of the beam and the shear span-to-depth ratio on the shear strength of steel fibre reinforced concrete beams. Background: Concrete is a material widely used in structures, as it has high compressive strength and stiffness with low cost manufacturing. However, it presents low tensile strength and ductility. Therefore, through years various materials have been embedded inside it to improve its properties, one of which is steel fibres. Steel fibre reinforced concrete presents improved flexural, tensile, shear and torsional strength and post-cracking ductility. Objective: A better understanding of the shear performance of SFRC could lead to improved behaviour and higher safety of structures subject to high shear forces. Therefore, the influence of steel fibres on shear strength of reinforced concrete beams without transverse reinforcement is experimentally investigated. Methods: Eighteen concrete beams were constructed for this purpose and tested under monotonic four-point bending, six of which were made of plain concrete and twelve of SFRC. Two different aspect ratios of beams, steel fibres volume fractions and shear span-to-depth ratios were selected. Results: During the experimental tests, the ultimate loading, deformation at the mid-span, propagation of cracks and failure mode were detected. From the tests, it was shown that SFRC beams with high volume fractions of fibres exhibited an increased shear capacity. Conclusion: The addition of steel fibres resulted in a slight increase of the compressive strength and a significant increase in the tensile strength of concrete and shear resistance capacity of the beam. Moreover, these beams exhibit a more ductile behaviour. Empirical relations predicting the shear strength capacity of fibre reinforced concrete beams were revised and applied successfully to verify the experimental results obtained in this study.