Modular Panels Research Articles

Modular steel panel for walls: life cycle environmental impact, life cycle cost, and potential for material circulation

The impacts of civil construction are widely recognized and justify the transition from a linear to a circular economy. Furthermore, with building users increasingly demanding greater adaptability, strategies such as modularity and flexibility to adapt to changing uses are being discussed. Modular wall panels allow quick installation and have the potential for disassembly, refurbishment, reuse, and recycling. We evaluate a modular steel panel system in two Brazilian case studies through life cycle assessment (LCA), life cycle cost (LCC), and building circularity index (BCI). The study applies the circular reuse and remanufacture, recycling, and life extension strategies for internal and external walls. For the external panel, the life extension strategy (SE02) stands out positively in all impact categories, with the lowest environmental impact and costs. However, the SE02′s BCI does not have the best result. The second best option is reuse (SE03), with the highest percentage of circularity. Furthermore, the differences between SE02 and SE03 are reduced in several impact categories, and the sensitivity analysis (transport, damage, and the number of reuses) shows that the differences could be even smaller. For the internal panel, life extension (SI02) and reuse (SI03) scenarios are the best options. Recycling (SI04) has the highest environmental impact and the best potential for circularity. BCI communication must be aligned with LCA and LCC, such that an increase in circularity is accompanied by a decrease in environmental impacts or with infeasible costs, especially for developing countries.

Prospects for the development of modular panels made of autoclaved aerated concrete in Poland

Prospects for the development of modular panels made of autoclaved aerated concrete in Poland

Analytical and clinical validation of a novel, laboratory-developed, modular multiplex-PCR panel for fully automated high-throughput detection of 16 respiratory viruses

Background: Viral respiratory Infections pose a health risk, especially to vulnerable patient populations. Effective testing programs can detect and differentiate these infections at an early stage, which is particularly important for high-risk clinical departments. The objective of this study was to develop and validate a multiplex PCR-panel for 16 different respiratory viruses on a fully-automated high-throughput platform. MethodsThree multiplex-PCR assays were designed to run on the cobas5800/6800/8800 systems, consolidating 16 viral targets: RESP1: SARS-CoV-2, influenza-A/B, RSV; RESP2: hMPV, hBoV, hAdV, rhino-/ENV; RESP3: HPIV-1–4, hCoV-229E, hCoV-NL63, hCoV-OC43, hCoV-HKU1. Analytic performance was evaluated using digital-PCR based standards and international reference material. Clinical performance was determined by comparing results from clinical samples with reference assays. ResultsAnalytical sensitivity (i.e. lower limit of detection (LoD), 95 % probability of detection) was determined as follows: SARS-CoV-2: 29.3 IU/ml, influenza-A: 179.9 cp/ml, influenza-B: 333.9 cp/ml and RSV: 283.1 cp/ml. LoDs of other pathogens ranged between 9.4 cp/ml (hCoV-NL63) and 21,419 cp/ml (HPIV-2). Linearity was verified over 4–7 log-steps with pooled standard differentials (SD) ranging between 0.18–0.70ct. Inter-/intra-run variability (precision) was assessed for all targets over 3 days. SDs ranged between 0.13–0.74ct. Positive agreement in clinical samples was 99.4 % and 95 % for SARS-CoV-2 and influenza-A respectively. Other targets were in the 80–100 % range. Negative agreement varied between 96.3–100 %. DiscussionLab-developed tests are a key factor for effective clinical diagnostics. The multiplex panel presented in this study demonstrated high performance and provides an easily scalable high-throughput solution for respiratory virus testing, e.g. for testing in high-risk patient populations.

Thermo-Environmental Performance of Modular Building Envelope Panel Technologies: A Focused Review

Modular construction is becoming famous for buildings because it allows a high degree of prefabrication, with individual modules easily transported and installed. Building envelope optimization is vital as it protects buildings from undesirable external environments by expressly preventing the incursion of outside elements. This research uses a systematic literature review to appraise the characteristics of modular envelope panels, focusing on hygrothermal and energy performance. A total of 265 articles were subjected to rigorous filtering and screening measures. The findings reveal notable inconsistencies in modular envelope terminologies and a lack of consistent performance measures, which present significant challenges for research and development efforts. Furthermore, the results indicate a predominant focus on hygrothermal and energy performance in existing studies, with limited attention to environmental impacts and other performance factors. Moreover, the existing literature primarily addresses modular envelope solutions in temperate climates, offering inadequate information for hot and hot–humid climate contexts. To address these gaps, this study proposes categorizing modular envelope panels into four distinct categories: active, passive, smart, and green/vegetated wall panels. These findings will benefit researchers, architects, building envelope designers, policymakers, and organizations developing building performance-related assessment ratings, standards, and codes. The study suggests adopting the categorization of modular envelope panels provided in this study and developing modular panels suitable for hot and humid climates to fill the existing knowledge gap.

A meta-analysis of sound isolation properties of various modular prefabricated wall systems

The current meta-analysis focuses on airborne sound isolation performances for modular prefabricated wall panels. As many properties may be varied in prefabricated wall assemblies, relying only on measurements either on prototypes in a lab or in situ tests would require a significant amount of resources. Understanding the precision and limitations of theoretical evaluation methods is, therefore, a must. A comparison of theoretical predictions with lab and field measurements (as per ASTM E90 or E336) is performed on multilayer systems up to a double wall panel system which incorporates four layers (two panels each composed of two layers). This allows a better appreciation of theoretical predictions of modular prefabricated wall systems.

Extremely tortuous sound absorbers with labyrinthine channels in non-porous and microporous solid skeletons

An assembly of additively-manufactured modules to form two-dimensional networks of labyrinthine slits results in a sound absorber with extremely high tortuosity and thereby a relatively low-frequency quarter wavelength resonance. Fully analytical modelling is developed for the generic design of such composite acoustic panels, allowing rapid exploration of various specific designs. In addition to labyrinthine channels in a non-porous solid skeleton, a case is also considered where the skeleton has microporosity such that its permeability is very much lower than that due to the labyrinthine channels alone. The analytical modelling is verified by numerical calculations as well as sound absorption measurements performed on several 3D printed samples of modular composite panels. The experimental validation required overcoming the non-trivial difficulties related to additive manufacturing and testing samples of extreme tortuosity. However, due to the two-dimensionality and modularity of the proposed design, such absorbers can possibly be produced without 3D printing by assembling simple, identical modules produced separately. The experimental results fully confirmed the theoretical predictions that significant sound absorption, almost perfect at the peak, can be achieved at relatively low frequencies using very thin panels, especially those with double porosity.

Near-fault ground motion effect on self-centering modular bracing panels considering soil-structure interaction

This study investigates the nonlinear seismic response behavior of self-centering modular steel bracing panel (SCMBP) systems subjected to near-fault ground motion records, considering the soil-structure interaction (SSI) effect. Analytical formulas for the load-displacement relationship of an SCMBP were validated through nonlinear 3D continuum finite element analysis while a simplified 2D wireframe model utilizing a constitutive spring model was verified by the 2D refined finite element model and subsequently adopted for time history analysis of the SCMBP structures with SSI effect. Based on the nonlinear time history analysis of a 6-story prototype building subjected to a suite of near-fault ground motions, the prototype structure is found to be able to re-center itself even under near-fault ground motion scaled to the design basis earthquake (DBE) level while frame members remain undamaged, except for fuse devices. Additionally, SSI reduces inter-story drift ratios under both far-field and near-fault ground motions. The findings provide insights into the promising performance of using SCMBP systems as a seismic strengthening system for sites with potential SSI effects and near-fault earthquake impact. The findings of this study can be insightful to other self-centering systems with flag-shaped story shear hysteresis.

Solar photocatalysis application in UWWTP outlets - simulations based on predictive models in flat-plate reactors and pollutant degradation studies with in silico toxicity assessment

The application of the solar photocatalysis for the degradation of residual pollutants found in surface water was demonstrated. Semi-pilot scale flat-plate cascade reactor (FPCR) was used to study the degradation of model organic pollutants: enrofloxacin (ENRO), 17β-estradiol (E2) and 1H-benzotriazole (1H-BT) over TiO2 thin-film supported on glass fibers. A modular panel with full-spectra solar lamps with appropriate UVB and UVA irradiation levels was used as a simulation of sunlight. Pollutant degradation in FPCR was estimated using predictive models; intrinsic reaction rate constants (ki) for ENRO, E2 and 1H-BT independent of the reactor size, flow rate and irradiation conditions were determined: 9.60, 3.35 and 0.37 109 s−1 W−0.5 m1.5, respectively. Main degradation products (DPs), formed upon hydroxylation, ring opening and oxidation, were identified using LC-QTOF-MS. The ecotoxicological impact was assessed via T.E.S.T. and ECOSAR open-source tools showing the formation of less harmful DPs after sufficient reaction time. Pollutant degradation was simulated at four locations of interest, i.e. exhausts from urban wastewater treatment plants (UWWTPs) in Zagreb, Croatia (45°N), Krakow, Poland (50°N), Sevilla, Spain (37°N) and Ioannina, Greece (39.6°N). Results have proved that a simple flat-plate system with supported photocatalysts can be easily scaled up and incorporated at the outlet of UWWTP for the reduction of pollutant load and related toxicity. The exhaust canal in Zagreb with the estimated length of a photocatalytic layer of 122 m for the > 90% degradation of all target pollutants was discussed as the best installation site among studied locations. Environmental ImplicationA multi-disciplinary approach to the tentative application of TiO2 solar photocatalysis outdoors to reduce pollutant loads and toxicity in surface waters was demonstrated. Possible application at four selected locations in Europe, as an additional step in water treatment after urban wastewater treatment plants (UWWTPs) was discussed. Target pollutants were studied under environmentally relevant conditions (sunlight levels, water matrix, simulation of process on a real scale at selected geographical location), at both higher and low concentrations.

Strengths and limits of a modular magnetic wall panel system

This paper explores the feasibility of fabricating and employing an innovative appendage-free modular magnetic interior wall system that allows non-technical users to modify interior spaces to their spatial needs without any need for specialized expertise. The modular magnetic wall panel system tested in this study is composed of free-standing panels with magnetized upright frames for tessellated linkage. In this project, real-scale prototypes were produced and roughly tested for stability to verify that manufacturing is possible and to identify areas for design improvement. Forces were enacted perpendicular to the panel façade in free-standing and linked configurations to mimic probable leaning behaviours by users. Results of rough tests confirm production feasibility and the stability of linked panel assemblies but design improvements must be applied to stabilize the free-standing configuration. Design development and possible enhancements are discussed based on findings. Standardized testing of the enhanced prototype is also recommended.

A critical review of circularity - ‘design for disassembly’ assessment methods applied in the development of modular construction panels - an Irish case study

The construction and operation of buildings has a significant negative impact on the environment and is a major contributor to global warming. The EU has responded with a range of policy measures including targets to decarbonise the existing building stock and to promote circular economy principles in the built environment.The Drive 0 project aimed to demonstrate potential for such accelerated decarbonisation of the building stock using circular modularised solutions, which necessitated the development and application of circularity - design for disassembly assessment methods, undertaken at key stages during the life of the project, to aid design development and benchmarking of proposed solutions, which is an identified knowledge gap in research.This paper presents a critical review of the Drive 0 circularity - design for disassembly assessment methods applied in the development of the Irish modularised wall panel, providing case specific insights into the challenges and complexity of implementing and assessing circularity and design for disassembly in buildings, drawing from relevant literature in the field, and contributing to key retrofit, modularity and circularity research needs notably case specific application in construction.Key findings were limitations of the simplified method in relation to; scope and range of indicators, non-hierarchical consideration, focus and weightings, material aspects and impacts, re-application stages, definitions and terminology, all of which provide theoretical consideration into the complexity of assessing the multi criterion nature of circularity and design for disassembly in practice.The critical analysis undertaken contributes to this emerging field of knowledge and provides a basis for further research in this field toward developing a more holistic circularity - design for disassembly assessment framework.

Modular sandwich panel system for non-loadbearing walls – Experimental mechanical, fire and acoustic testing

Investment in the construction industry has increased over the last years and conventional construction materials, techniques, solutions and practices cannot meet the current needs. Resources are not being used to their full potential and there is a lack of manpower. It is vital to evolve encouraging sustainable and quality cost-effective materials, techniques, solutions and practices, therefore also enhancing the construction workers’ quality of life. This work proposes a new modular sandwich panel system for interior walls partition applications. The modular sandwich panel is made of an extruded polystyrene boards (XPS) core and has three options as facesheets: gypsum plasterboard (PGC), fire resistant gypsum plasterboard (PGF) and magnesium oxide board (MGO). This is an alternative solution for partition walls based on five main factors: it has the potential to be reused; its modules are self-supported (they do not need vertical metal studs from floor to ceiling); it is easy to install (on-site) by only two people; it is quick to install; and it provides easy local access to the interior of sanitary facilities. This work also includes experimental research for evaluation of proposed the wall solution in terms of mechanical resistance and stability, fire safety and airborne sound insulation between adjacent rooms. Mechanical resistance testing includes impact resistance tests, simple compression load tests, sanitary appliance load tests and endurance cycle load tests. Fire resistance testing allows to assess the integrity and maintenance of the panel wall under fire conditions. Acoustic experiments aim to determine the weighted standardised sound level difference (DnT,w) between adjacent compartments separated by the proposed panel wall system. Mechanical resistance tests indicate that the panel wall system has acceptable mechanical performance, including the connections between the panel wall modules. Results indicate that fire resistance and sound insulation characteristics of the panel wall can be enhanced.

Comparative Study to Assess the Thermal Behaviour of Sandwich Roof Panels with Coconut Fibre as an Alternative Core Material to Polyurethane

Sandwich panels (modular panels) promote optimal solutions to some major issues prevailing in the construction industry such as increased energy consumption by building elements, excessive disposal of constructional waste and unproductive time spent during construction. Hence, the inclination towards sandwich elements has been increased vastly deviating from conventional building construction materials and methods. However, the potentiality of using locally available natural materials for the development of sandwich panels is a salient sustainable approach that needs to be addressed. This study evaluates the current and potential materials used in modular panels and key properties of sandwich panels including mechanical, thermal insulation, and sound insulation properties. Moreover, various test methods followed, and standards specified to investigate the mechanical, thermal and acoustic insulation properties are also discussed. The possibility of using coconut fibre as a locally available natural alternative core material to polyurethane core of sandwich panels has been evaluated using simulations based on the material properties obtained from literature. The study identifies coconut fibre as a potential alternative core material for sandwich roof panels as it reflects nearly similar thermal behaviour to polyurethane.

Robotic arm three-dimensional printing and modular construction of a meter-scale lattice façade structure

Recent advances in additive manufacturing have made the construction of large-scale 3D-printed structures possible. However, most case studies so far have primarily used concrete as the building material and regular geometries as structural forms. In this work, we present a recently built structural art installation located in Shanghai that is composed of lattice panels with regular and irregular shapes enabled by robotic arm 3D printing. To fabricate the spatial lattice structure, we developed a customized end effector for extrusion-based additive manufacturing using a robotic arm. With the developed printing head and printing path control algorithm, the modular lattice structural panels were printed using ABS material via an industrialized robotic arm and then assembled on the site as a facade. This study showcases the potential to use such modular 3D-printed lattice structures with more freedom in form and partially replace labor with robotic arms for accelerated construction and reduced cost.

An origami shield with supporting frame structures optimized by a feature-driven topology optimization method

In this paper, the design, manufacture and testing of an origami protective shield with a supporting frame structure are presented. It consists of an origami shield surface and a deployable supporting frame structure that needs to be portable and sufficiently stiff. First, for the design of the shield surface, a three-stage origami crease pattern is developed to reduce the shield size in the folded state. The shield surface consists of several stiff modular panels and layered with flexible fabric. The modular panels are made of a multi-layer composite where a ceramic layer is made of small pieces to improve durability as those small pieces enable restriction of crack propagation. Then, the supporting frame structure is designed as a chain-of-bars structure in order to fold into a highly compact state as a bundle of bars and deploy in sequence. Thus, a feature-driven topology structural optimization method preserving component sequence is developed where the inter-dependence of sub-structures is taken into account. A bar with semi-circular ends is used as a basic design feature. The positions of the bar’s end points are treated as design variables and the width of the bars is kept constant. Then, a constraint on the total length of the chain of bars is introduced. Finally, the modular panels made of multi-layer composite and the full-scale prototype of the origami shield are fabricated and tested to verify the bullet-proof performance.

Parametric design of a modular acoustic panel for sound recording space versatility

Increasingly sound recording studios are demanded to host projects of different acoustic needs. However, their sonic character, product of their contents and bulky conventional treatment solutions, usually remains unchanged. This paper reports a modular panel's early-stage design, aimed at providing flexibility to a group of representative recording rooms. The versatility refers to acoustical (absorption and diffusion), practical (volume and weight), and aesthetic aspects. The geometry and materials of the panel were derived parametrically through computer modelling software, by implementing interdependent and adaptable elements to one unit. Existing recording spaces were recreated into computational acoustic models and tested in two states. Simulations of the rooms' acoustical behaviour were run in turn, first with the original treatment, then with the panel replacing the treatment. The design goal was to have minimal differences in Reverberation Time, Early Decay Time, Clarity, Room Frequency Response for every room's two states. Results showed the panel performing better in rooms with larger volume. Overall, the panel matched the original acoustic response and character of the rooms, while providing versatility when compared to traditional acoustic treatment solutions. The development of such a product would allow future studio users fine tune the room's performance according to their needs.

Numerical Investigation on Fire Performance of LSF and Steel Modular Floor Panels

The steel Modular Building Systems (MBSs) that have been influenced by the Light-gauge Steel Frame (LSF) techniques have become a prominent culture in the industry. However, the detrimental behaviour of steel structural components at high temperatures has elevated the risk of fatal accidents in the event of a fire. Although several research investigations have addressed the fire performance of steel modular wall systems, the behaviour of modular floor systems has not been adequately addressed in the state of the art. Hence, to promote the fire safety and optimum design techniques in the modular construction industry by addressing the aforementioned research gap, this study investigated 48 conventional LSF and MBS floors for their structural and insulation Fire Resistance Levels using Finite Element Modelling (FEM) and Heat Transfer Analyses (HTA) techniques. Initially, full-scale experimental fire tests were modelled using FEM methods, and the validity of the techniques was verified prior to the analyses of parametric floor systems. Furthermore, the structural behaviour of the channel section joists in the elevated temperatures was studied, and hence a correlation was established to determine the critical steel temperature at the structural fire failure with respect to the applied Load Ratio (LR). An additional 12.5 mm thick plasterboard sheathing on single plasterboard sheathed floors resulted a 30 min improvement in structural and insulation FRLs. In addition, the modular floor systems demonstrated enhanced structural and insulation Fire Resistance Levels (FRLs) against the corresponding conventional LSF floor designs due to double LSF skin build-up. The incorporation of rockwool insulation and the increase in the insulation volume implied increased structural and fire performances. However, insulation material in the modular designs was more effective. The fire-rated conventional and modular LSF floor systems are expected to be practised in the construction industry to achieve required fire resistances with optimum material usage.

Affordable wall panels using sustainable waste materials: a review

With the enormous population growth in the last few decades, there is a demand for infrastructure development and rapid urbanization that result in the depletion of natural resources, emission of greenhouse gases, and subsequently, exacerbation of the climate crisis. Moreover, waste materials generated by different industries such as the construction industry end up by burning or dumping them in landfills further posing serious health hazards. Besides, skyrocketing prices of housing and limited income of major population groups have resulted in the housing crisis. Therefore, it is imperative to find low-cost, environment friendly and sustainable solutions to mitigate aforementioned problems. The literature indicates that the modular construction method could be a viable solution that can reduce waste generation and construction costs. This method has been extensively used in many parts of the world in different applications mostly in the construction of low-rise buildings. However, with the advent of technological advancement in the construction industry, studies have shown that modular construction can also be successfully employed for medium and high-rise buildings. This paper presents a holistic review of the existing literature on the development of modular wall panels to foster sustainability and alleviate the housing gap. To this end, a proactive approach has been undertaken to identify key research areas to study the use of waste materials in the development of modular wall panels. The results of the literature review revealed that modular wall panels have the potential to substantially reduce the construction cost and carbon footprint. The barriers to the growth of modular construction were also discussed in this paper.

Influence of the number of levels and system age on greywater treatment in a green wall

The use of green walls for greywater treatment represents a great opportunity to reduce potable water consumption and achieve multiple benefits. This study aims to analyse the efficiency of a pilot scale open-air green wall and evaluate its durability over time. The green wall consists of two modular panels (P1 set up in 2020, and P2 in 2018), each including nine pots organised in three independent columns. Coconut coir (80%) and perlite (20%) were used as filter media for three ornamental plant species (Carex morrowi, Hedera helix, Lonicera nitida). Each column was individually fed in batch mode with 24 Lday−1 (hydraulic loading rate - HLR 740.8 Lm−2 day−1) of greywater from January to March 2021. 190 water samples were analysed for 13 physical-chemical parameters. Both panels exhibited very good removal efficiencies for TSS (P1: 97.4 ± 4.6%, P2: 89.1 ± 13.8%), BOD5 (P1: 98.8 ± 2.4%, P2: 94.5 ± 9.2%), COD (P1: 78.5 ± 5.2%, P2: 80.1 ± 4.2%), TN (P1: 49.2 ± 30.4%, P2: 48.0 ± 23.31%), MBAS (P1: 92.7 ± 3.8%, P2: 75.3 ± 8.0%). P1 reached satisfying pollutants removal after two levels, while P2 showed higher variability and frequent clogging phenomena, needing three levels (e.g., cumulative BOD5 removal along the three levels in P1: 45.2 ± 36.2% | 86.5 ± 14.8% | 98.8 ± 2.4%; in P2: 16.5 ± 20.8% | 51.8 ± 32.3% | 94.5 ± 9.2%). This highlighted that the third level of P2 was necessary to guarantee good performances after over 2 years of operation. This study confirmed that green walls have high potential in greywater treatment also in challenging conditions (i.e. winter climate, high HLR and operating times), opening to further studies devoted to extending their lifetime.

Performance-based design of steel frames with self-centering modular panel

The self-centering modular panel (SCMP) is an emerging seismic resilient lateral force-resisting system. This paper intends to develop a performance-based design (PBD) method for steel buildings equipped with the SCMPs based on the concept of direct displacement-based design methodology. The theoretical hysteretic model of the SCMP consisting of the post-tensioned frame (PTF) and four replaceable hysteretic dampers (RHD) is proposed and validated in this paper. Based on the proposed theoretical hysteretic model, the equation for the equivalent damping ratio of the steel buildings with SCMP is developed and the PBD method is proposed. The 3-story and 6-story steel frames equipped with the emerging SCMP are established through the developed PBD procedure. Static analyses were performed to investigate the nonlinear responses of the established buildings. Twenty ground sequences were chosen and scaled to evaluate the seismic responses of the designed steel frames subjected to different seismic intensity levels through nonlinear dynamic analyses. The results of the research show that steel structures equipped with SCMPs established through the developed PBD procedure can display the expected hysteretic behavior and performance under earthquakes. The designed buildings can achieve excellent post-earthquake recoverability by keeping the residual displacement in each story less than 0.5% even under earthquakes with MCE intensity.

MosSkin: A moss-based lightweight building system

A low cost and lightweight moss envelope system for buildings has been developed to address the problem of the lack of greening in densely urbanized areas. Several moss species have been sampled in the wild, selected, based on their ability to tolerate the abiotic stresses of urban environments, cultivated in controlled conditions and tested for their growth capacity on different (building) materials. Five of these showed the most promising results in terms of growth speed and coverage, proving the most suitable for the development of the greening system: Homalothecium sericeum, Barbula unguiculata, Pseudoleskea incurvata, Grimmia pulvinata and Hypnum cupressiforme. An in vitro growing method was also set up for large scale moss cultivation and application.A modular multi-layer panel, with a built-in irrigation system, has been developed, designed and tested. MosSkin is a low-cost low maintenance, versatile and lightweight system, with interesting performances in terms of water management and surface temperature reduction (up to 14 °C).