Metal Deck Research Articles

Sustainable layout design of steel buildings through embodied energy and costs optimization

Structural design process is a major phase in construction that has an impact not only on the cost of the project but on the environmental aspects as well. Although the majority of structural engineers aims to reduce the structural cost by reducing the weight of the elements, yet a handful of engineers has the information required to consider the environmental impact of their decisions. This paper presents an attempt to develop a multi-objective optimization model for steel floor structural system against cost and embodied energy using genetic algorithm. In addition, a novel study is conducted to address the embodied energy values for structural materials is Egypt. The presented model allows for determining the optimum layout of certain space taking into consideration the architectural constraints imposed on this space. In this optimization problem, the layout configuration of the steel beams, the steel beams profiles, the metal deck thickness, and the concrete slab thickness are determined. The developed model is elaborated along with the results of applying the model on two problems, which shows its ability to address several types of applications.

Validation of FE modeling of cold-formed tube lightweight concrete composite system

Experimental testing of composite beams takes a long time, and usually complicated, and necessitates massive testing facilities. After validation, finite element modeling can be utilized for understanding the fundamental behavior of composite beams. Unfortunately, no available experimental data has been found regarding the composite behavior of a cold-formed steel tube section and a lightweight concrete slab with a metal deck. Therefore, this study aims to validate the FE modeling for different components of the composite system by contrasting numerical results with the corresponding published experimental data for the specific component. Firstly, the FE modeling for a separate cold-formed tube beam has been validated by contrasting it to the experimental data with emphasis on the imperfection modeling and post-buckling behavior. Then an experimental data for lightweight concrete beam has been adopted to validate the FE modeling for lightweight concrete. Finally, the FE modeling for the hot-rolled composite beam has been conducted and compared with the experiments for the validation of the composite action as well as the contact between the beam and the supported slab deck.

Numerical Study of Composite Steel Cellular Beam System Using Demountable Shear Connectors

AbstractSteel concrete composite beams have been increasingly adopted in practice due to their advantages with respect to their structural features and constructability. However, in conventional composite beam systems the composite action is applied via the shear connectors welded at the top flange of the downstand steel beam and embedded in the concrete slabs, making the disassembly of the beam system and reuse of any component impossible. This paper presents a numerical study of a new composite beam system with a steel cellular beam, metal deck flooring and using demountable shear connectors. According to the experimental study, this composite beam system made the demounting, reassembly and member reuse possible, and did not compromise the loading capacity. In the numerical study presented in the paper, the finite element model was developed and validated against the results obtained from the experimental study. The parametric study further examined the effects of concrete strength, shear connector arrangements etc. The comparison and analysis clarified the mechanism of the demountable shear connector and the effect of construction method on the load capacity of the composite beam system, and provided a deeper insight into the behavior of this type of shear connector. Through this numerical study, the structural merits of the composite beam system using demountable shear connectors were highlighted.

Flexural strength test on new profiled composite slab system

This research presents an experimental study on the flexural strength and failure behaviour of a newly developed composite metal decking system. The newly developed metal decking system with a thickness of 0.75 mm and 1.0 mm produced by the industry requires a detailed study in strength and performances before it is launched for commercialization. A simply supported conventional reinforced concrete slab is used as the control specimen and two composite slabs with different metal thickness of steel sheet profiles were constructed and tested under a four points flexural strength test. The strength and behaviour of the slabs are recorded and comparisons with conventional slabs with composite deck slabs are made to achieve the objectives. The recorded results of three different slabs were then used to plot a load-displacement graph and deflection profiles are to be analysed and compared. The yield flexural capacity and average yield displacement of specimens for the composite slabs were 28.0 kN and 0.80 mm respectively. The 1.0 mm metal thickness composite slab has the highest ultimate flexural capacity among all specimens which is 84 kN followed by a 0.75 mm metal thickness composite slab with 58 kN and ends with the lowest 9.1 kN of conventional slab. Two cracking patterns were found during the experimental test which includes shear cracking and flexural cracking`. Besides that, two major failure modes under bending which are flexure failure at the centre point of the specimen and bond or longitudinal slip failure along the side of the specimen were found in the experimental test. Bond failure results in slippage between the concrete and metal deck, which can result in cancellation of the composite action at interface. In conclusion, the strength of slabs improved, and ductility was remarkably increased when slabs acted as a composite structure.

Push-out Test of Profiled Metal Decking Slabs with Cold-formed Steel Beams and Rebar Shear Connector

New methods to provide shear strength on the cold-formed steel (CFS) lipped c-channel section composite beam encased with concrete partially is proposed using rebars embedded in concrete. The development of research on the CFS composite beams technology with partial encasement shows that the section of the composite beam encased with concrete partially can provide ductile flexural action for the composite beam. The application of profiled metal decking slabs in the composite beam is becoming increasingly popular compared to solid slabs. However, it has a detrimental effect on the structural behavior of a composite beam. This research is aimed primarily at presenting the behavior of the rebar shear connector to evaluated ductility, shear capacity, and modes of failure. Two samples using a rebar 12 mm in diameter in the profiled metal decking slabs and solid slabs were tested using the standard push-out test till failure. For the composite beam design, the proposed shear connector embedded in the slab concrete and the CFS encased with concrete partially used the test results’ shear capacity, greater than the values as proposed by section 3.1, BS 5950. Due to rebars shear-off, the solid slab specimen failed with the highest load of 489.6 kN while the Profiled Metal Decking Slab specimen failed due to the formation of the cracks on the PMDS at 421.1 KN ultimate loading.
 HIGHLIGHTS
 
 A new system of the rebar shear connectors for the Cold-Formed Steel (CFS) composite beam partially encased in concrete have been developed
 The main purpose of push-out testing is to investigate the shear capacity and ductility of the proposed shear connector failure modes and load-slip connections
 The shear capacity of the test results is greater than the values as indicated by BS 5950 Part 3.1
 The proposed rebars as a shear connector for partly embedded CFS can be used in the construction
 
 GRAPHICAL ABSTRACT

Rainwater Harvesting System Integrated With Sensors for Attic Temperature Reduction

This cool roof system focuses on utilization of rainwater harvesting systems by integrating the smart sensor to cool the roof and attic temperatures for the improvement of comfort level of building occupants. An ideal cool roof technology system is basically made up of these three components: (1) moving-air-cavity (MAC) ventilation, (2) solar-powered fan and (3) rainwater harvesting system. These three main components integrate to perform and control the cool roof system. Four small-scale cool roof models were designed and constructed to inspect the performance of the rooftop and attic temperatures. The experimental work was carried out indoors by employing the halogen lamp as the replacement for solar irradiation, while the ambient temperature is monitored to be around 29.8 °C throughout the test. The temperatures of the rooftop surface, MAC aluminum tube, and attic region were measured by K-type thermocouples to evaluate the performance of the cool roof designs. The solar-powered fans were incorporated into the MAC, which accelerated the airflow rate within the cavity and rejected the hot air out before transferring it to the attic region. Meanwhile, an innovative rainwater harvesting system was executed to cool the rooftop temperature rapidly by reducing the rate of heat transfer to the attic region. The result of this inventive cool roof system (Design Z) has successfully reduced the attic temperature by 10.8 °C compared to the normal metal deck roof model (Design W). The findings of the project revealed that the integrated cool roofing technology system comprises the ability to enhance the comfortability of building occupants toward a long-term sustainable development for a better world.

Sefaira Simulation in Residential Houses to Determine the Energy Use of Wall Materials

Wall material popularly used in Indonesia is a masonry wall, where the process takes longer than prefabrication wall materials or houses built-in components such as panels or modules. In this study, four types of prefabrication wall materials will be analyzed based on the annual energy use of each material. The wall materials chosen are Hebel, Alderon, Glassfibre Reinforced Cement Board (GRC), and metal deck. The calculation of energy consumption uses a simulation of a 27 m2 one-floor residential building located in Bandung City, West Java, Indonesia. Furthermore, the simulation is analyzed with Sefaira software based on ASHRAE 90.1 - 2013. From the results of this Sefaira analysis, it is obtained that the Energy Use Intensity (EUI) value for Hebel wall material is 58 kWh/m2/yr, Alderon wall 90 kWh/m2/yr, Glassfiber Reinforced Cement Board (GRC) 83 kWh/m2/yr, and metal deck 89 kWh/m2/yr. Among the four recommended prefabricated wall materials, Hebel materials are considered to have the least energy use. Meanwhile, the EUI target of the 2030 Challenge for residential houses is 38 kWh/m2/yr, so it must reduce as much as 45 kWh/m2/yr for Hebel material.

The combination of green construction method and the use of tabas waste as a substitute for cement

Green construction is a construction process that carries the concept of sustainability where the construction process can reduce environmental degradation by utilizing existing waste in the surrounding environment, contributing to reducing the level of environmental pollution, and being able to reduce waste from the construction itself. The use of tabas as a substitute for cement is one of the implementations of the green construction concept itself, where the waste of rock that produced by the temple stone craftsmen ranges between 20%-30%, which utilization is not optimal, so it often becomes waste that accumulates in the production area so that it can damage the environment due to the compounds of the tabas waste. The use of rock as a substitute for cement both reducing the amount of cement usage which produces 8% CO2 emissions where the percentage is the third-largest in the world even far beyond aircraft fuel. From the results of the study using tabas rock to replace 10% of the volume of cement in the mixture, obtained a concrete strength of 22.21 MPa so that it meets the criteria as normal concrete. With the combination of green construction methods using a combination of tabas concrete and metal deck floor plates, in terms of the cost of making concrete are obtained savings by 20.48% and a reduction in the amount of construction waste originating from formwork by 35.96%.

Integration of Lightweight Foam Concrete Roof, Moving-Air-Cavity, and Solar-Powered Fans for Attic Temperature Reduction

This paper presents a novel cool roof technology system that promotes both passive and active cooling methods in reducing the attic temperature of the building. The project aimed to evaluate the effect of various roof model designs on the heating load to establish the capacity of a cooling roof system by maintaining the thermal comfort level for occupants in the buildings. There are four main components in constructing the cool roof models: 1) metal deck roof, 2) lightweight foam concrete roof, 3) moving-air-cavity (MAC) ventilation, and 4) solar-powered fan. Four small-scale cool roof models were built to evaluate the performance of each cool roof design. The performances of the roof surface and attic temperatures of each designed cool roof models were compared with the conventional metal deck roof. The roof models were conducted indoors by using halogen spotlights. The result of the Roof Design IV with the integration of lightweight foam concrete, MAC, and solar-powered fans has effectively reduced the attic temperature by 6.0°C compared with the normal roof model (Roof Design I). As a result, this integrated cool roof design comprises the ability to enhance the comfortability of occupants toward long-term sustainable development with the utilization of renewable energy to protect the natural environment.

Experimental investigation of shear connector behaviour in composite beams with metal decking

Presented are experimental results from 24 full-scale push test specimens to study the behaviour of composite beams with trapezoidal profiled sheeting laid transverse to the beam axis. The tests use a single-sided horizontal push test setup and are divided into two series. First series contained shear loading only and the second had normal load besides shear load. Four parameters are studied: the effect of wire mesh position and number of its layers, placing a reinforcing bar at the bottom flange of the deck, normal load and its position, and shear stud layout. The results indicate that positioning mesh on top of the deck flange or 30 mm from top of the concrete slab does not affect the stud\' s s strength and ductility. Thus, existing industry practice of locating the mesh at a nominal cover from top of the concrete slab and Eurocode 4 requirement of placing mesh 30 mm below the stud\' s head are both acceptable. Double mesh layer resulted in 17% increase in stud strength for push tests with single stud per rib. Placing a T16 bar at the bottom of the deck rib did not affect shear stud behaviour. The normal load resulted in 40% and 23% increase in stud strength for single and double studs per rib. Use of studs only in the middle three ribs out of five increased the strength by 23% compared to the layout with studs in first four ribs. Eurocode 4 and Johnson and Yuan equations predicted well the stud strength for single stud/rib tests without normal load, with estimations within 10% of the characteristic experimental load. These equations highly under-estimated the stud capacity, by about 40-50%, for tests with normal load. AISC 360-16 generally over-estimated the stud capacity, except for single stud/rib push tests with normal load. Nellinger equations precisely predicted the stud resistance for push tests with normal load, with ratio of experimental over predicted load as 0.99 and coefficient of variation of about 8%. But, Nellinger method over-estimated the stud capacity by about 20% in push tests with single studs without normal load.

Collapse Simulations of Steel-Concrete Composite Floors under Column Loss Scenarios

Characterizing structural resiliency after severe damage to a few load-carrying members is challenging. Engineers use various computational approaches to assess the vulnerability of structures and to evaluate the parameters that affect their response. Few of these approaches are capable of predicting the actual peak load-carrying capacity a damaged structure can withstand before experiencing total collapse, and practically none of them have been verified against actual test results. In this paper, experimental data from large-scale tests on steel–concrete composite floor systems under different column loss scenarios were used to develop and to validate a high-fidelity numerical modeling approach capable of predicting the response of the tests up to total collapse. This approach incorporates geometric and material nonlinearity, explicit modeling of steel and concrete failure, and contact modeling using LS-DYNA version R10.2.0. Nearly all specimen components were modeled using brick elements, including the concrete slab, steel members, bolts, and other connecting elements. The corrugated metal decking was represented with shell elements, and beam elements represent the reinforcing steel and shear studs. The predicted response and ultimate load–carrying capacity up to total collapse show good agreement with the results of the experimental tests. Validating the numerical models revealed the sensitivity of various modeling parameters and demonstrated the potential for inaccurate predictions of response when certain parameters were not correctly specified. The most important of these parameters are described in this manuscript. Lessons learned from the current study are helpful for understanding the mechanisms that have the greatest impact on collapse of composite floor systems, and these lessons can be used to gain insight on the collapse potential of other structures with different geometries or configurations.

COMPARISON OF CONVENTIONAL SLAB AND METAL DECK COMPOSITE SLAB METHOD TO TIME AND COST IN TRANSPARK CIBUBUR PROJECT

in the implementation of the Transpark Cibubur project, especially in Tower C Apartment there are several problems in conventional slab methods including the need for a longer construction time. With some thoughts and considerations, the work method of floor slab was changed from conventional method to metal deck composite slab method. In this research, a comparative of conventional slab and metal deck composite slab method in Tower C of the Cibubur Transpark Project is the object of research to compare the two methods to speed of implementation and cost requirements. The analysis results show in Tower C 16th to 19th floor for metal deck composite slab method is more expensive than conventional slab method with a cost difference Rp. 137.252.215,54. While in terms of work time, conventional slab method are longer than metal deck composite slab method with a time difference for 25 days.

Experimental investigation into acceptable design methods for cold-formed metal deck

Cold-formed metal deck is commonly used in the construction of modern buildings. It is readily available and cost effective in many applications. Conservative design tables provided by metal deck producers aid the engineer of record and encourage use of the product.The American Iron and Steel Institute has embraced advanced analysis techniques, particularly the Direct Strength Method and Effective Width Method, which can be used to analyze a variety of thin gage, cold-formed structural shapes, presumably including deck. These methods have become popular with designers, as they have shown to reflect accurate flexural capacities for many standard cold-formed shapes. Until recently, these methodologies have not been applied to the analysis of metal deck. The objective of this research initiative is to compare the results of both the Direct Strength Method and Effective Width Method to experimental results for several metal deck profiles and gages and evaluate the numerical methods' applicability to metal deck.The experimental program comprises 54 full-scale tests of several depths and gages of roof and floor deck. Experimental results are compared to results from numerical methods. It was found that both numerical approaches reasonably predicted the flexural capacity of shallow roof deck, but numerical predictions deviated from experimental results as deck became deeper. Thickness of the deck (gage) played a role, and as deck became thinner the numerical methods showed a larger discrepancy from experimental results.

Bending experiment on a novel configuration of composite system using rebar as shear connectors with partially encased cold-formed steel built-up beams

In order to achieve greater ductility and strength, as well as to produce a more economical design, a novel composite beam and floor system have been developed to achieve higher strength and ductility, as well as to yield a more economical design purpose. This paper has put focus on this newly developed composite beam system which consists of a profiled metal decking slab made with self-compacting concrete (SCC). It has been joined cold-formed steel (CFS) built-up beams. These beams have been infilled with SCC by means of U-shaped rebar used as shear connectors. The researcher, in order to construct an open section, put together two CFS C-lipped channel sections in a back-to-back formation, and to construct a closed section, the formation was made to be toe-to-toe. The flexural behaviour of the partly encased composite beam was evaluated through experimentation by the researchers. So that the researchers could observe the failure modes and flexural capacity of the construction, a four-point bending test procedure was performed on two samples taking into consideration both closed and open built-up beam sections. The results of the test demonstrated that the open sections were able to exhibit a 24 percent higher ultimate moment capacity as well as greater stiffness and higher vertical deflection. As can be seen from the results of the experimental bending test, the built-up design had a great impact on the capacity and deflection of the section, and the section that was encased was able to reach the ultimate strength when the proposed shear connector was placed in the composite action. In order to validate the present test results, the design and analysis of the new composite beams have been evaluated.

Cost comparison analysis of slab structure using concrete beam and steel beam

Cost planning is an important phase on construction project planning to give illustration to the owner how much cost they should spend to execute that project. The slab is an element of the structure that has a large amount of the quantity so that affects the cost of the whole project. Then the cost comparison of slab structure has to be analyzed to know the most optimum design between conventional shuttering with the concrete beam on the initial design, first alternative options design, and metal deck shuttering with steel beam on second alternative design. The calculation of the slab structure cost analysis were based on Indonesia’s standard (PermenPUPR and SNI). The result is the first alternative options design that using concrete beam were cheaper 10,24% than the initial design that using concrete beam too while the second alternative options design that using steel beam were more expensive 27,14% than the initial design.

Mapping of construction waste for eco-costs per value ratio (EVR) index using Google My Maps in Shah Alam, Malaysia

Construction waste is one of the major challenges faced in our world today. The residential, commercial and infrastructure industries in Malaysia are recognised as rapidly growing sectors that indirectly bring economic growth to our country. However, the generation of waste in the construction industry is increasing in proportion to the development of new construction. This increase has resulted in negative environmental impacts. To address these issues, the present study focused on the mapping of construction waste generation in low-rise residential construction sites in Shah Alam district, Selangor, using the Google My Maps application. Information on construction waste generation data such as coordinates, photos, types of materials, types of waste, quantity of waste, gross floor area, labour cost, material life-spans and eco-costing per value ratio (EVR) index for monitoring was gathered manually through case studies and site observations over 14 months—the contract period. The collected data was inserted into Google My Maps and AppSheet for the mapping process. The findings of this analysis were based on five selected sample sites in Shah Alam that were under construction from 2013 to 2017. The results identified a total of nine types of construction waste, i.e. rebar and BRC, concrete grade 25, timber formwork, bricks, plaster cement, tiles, drywall, metal deck roofing and ceiling. These types of waste accounted for varying values of the EVR index in the construction projects during the contract period. The system proposed by this study will help to monitor the total construction waste generated from the start of a project and will potentially result in the reduction of construction waste, thereby contributing to sustainable construction.

Behaviour of Composite Beam Arranged as Boxed-Section With C-Channel of Cold-Formed Steel of Lipped Section

Cold formed steel (CFS) of lipped C-Channel sections are commonly use because of their simple forming procedures and easy to erect. To improve the flexural strength of the proposed composite beam, the C-channel of Lipped section is arranged toe-to-toe to form into boxed shape section and filled with self-compacting concrete (SCC). Reinforcement bars was used in a tension zone to increase the flexural strength of the proposed beam in this experimental study. A U-shape re-bars was installed to act as shear connections between concrete slab and beam of boxed section filled with self-compacting concrete. Two specimens were prepared and tested until failure. A C-channel section of size 250mm deep, 75mm width, and 2.4mm thick was used for the proposed composite beam section. Longitudinal rebar’s size of 16mm and 20mm were installed at the bottom of the beam encased by the self-compacting concrete of 50MPa. A U-shape re-bar if size 12mm in diameter was used as a shear connector and functioned as vertical shear resistance for the beam system. The beam is kept restrained in position by a profiled metal decking installed on top of the beam to form a slab system also cast using by SCC. The specimens were tested under pure bending arranged as simply supported beams. It was found that the moment resistance of the experimental results agreed well with the predicted numerical analysis.

Analysis of Use of Welded Angle and Drop Hollow as Reusable Temporary Supporting in Metal deck Slabs Viewed From Performance of Costs And Time

Like the project in general, slab work on Project Indonesia 1 uses one material, namely metal deck. The upper structure slab consists of 64 floors with a majority of 90% using a metal deck system. Where these components require support that can carry the workload, rebar, and fresh concrete. Starting with Metaldeck's non-reusable / fixed supporting (angle & anchor) design which is quite difficult to apply in the field, it has an impact on increasing time and increasing the cost of work. So the engineering team has the innovation of replacing non-reusable / fixed supporting material (angle & anchor) with reusable material (angle & drop hollow). Cost analysis is sought by calculating the RAB (Cost Budget Plan) using the unit price analysis used by the DKI Jakarta Government and how efficient the time gained. Based on the results of calculations and interviews with relevant experts on the project, the implementation of temporary supporting work costs was carried out using a non-reusable method of Rp.3,211,000,000.00. As for the implementation of the reusable method of Rp.649,916,800. There is a difference in cost between the non-reusable and reusable methods of Rp. 2,561,083,200.00. Where to implement the temporary supporting reusable method is cheaper than using the non-reusable initial method. Then in terms of installation time, the temporary supporting using the non-reusable method was 520 days while for the reusable method it was 260 days. There is a difference between the non-reusable and 260-day reusable methods. The results obtained that the use of Welded Angle & Drop Hollow as Temporary Supporting is more effective and efficient than using the initial Non-reusable method.

Developing a modified IDA-based methodology for investigation of influencing factors on seismic collapse risk of steel intermediate moment resisting frames

Incremental dynamic analysis (IDA) widely uses for the collapse risk assessment procedures of buildings. In this study, an IDA-based collapse risk assessment methodology is proposed, which employs a novel approach for detecting the near-collapse (NC) limit state. The proposed approach uses the modal pushover analysis results to calculate the maximum inter-story drift ratio of the structure. This value, which is used as the upper-bound limit in the IDA process, depends on the structural characteristics and global seismic responses of the structure. In this paper, steel mid-rise intermediate moment resisting frames (IMRFs) have selected as case studies, and their collapse risk parameters are evaluated by the suggested methodology. The composite action of a concrete floor slab and steel beams, and the interaction between the infill walls and the frames could change the collapse mechanism of the structure. In this study, the influences of the metal deck floor and autoclaved aerated concrete (AAC) masonry infill walls with uniform distribution are investigated on the seismic collapse risk of the IMRFs using the proposed methodology. The results demonstrate that the suggested modified IDA method can accurately discover the near-collapse limit state. Also, this method leads to much fewer steps and lower calculation costs rather than the current IDA method. Moreover, the results show that the concrete slab and the AAC infill walls can change the collapse parameters of the structure and should be considered in the analytical modeling and the collapse assessment process of the steel mid-rise intermediate moment resisting frames.

Grid-Connected Photovoltaic System Performance Prediction using Long-Term Weather Data

This aim of this paper is to evaluate the accuracy of long-term weather data models for performance prediction of grid-connected photovoltaic (GCPV) systems. The analyses were done for a 6-year old metal deck roof retrofitted GCPV system located in Shah Alam, Malaysia. The monthly and annual energy yield of the actual field data for three consecutive years were compared with the predicted yield using the long-term weather data models. These models were the Typical Meteorological Year (TMY), Model Year Climate (MYC), Microclimate data, and statistical Long-Term Mean for ground station data at Subang. The findings can be a reference for photovoltaic (PV) system designers on the range of accuracy when using the weather data models for performance predictions of GCPV system in Malaysia.