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1. Spatiotemporal temperature prediction in 3D-printed sulfur concrete for automated construction on Earth and beyond

   Boldini, A; Giwa, I; Kamel, E; Kazemian, A (October 2025, Automation in construction)

   Construction 3D Printing (C3DP) with sulfur concrete holds great potential for sustainable construction on Earth and beyond. However, a key challenge is optimizing the thermal C3DP process to minimize layer deformations while enhancing interlayer adhesion for improved mechanical strength. To tackle this challenge, this paper presents a physics-based model of heat transfer within a 3D-printed sulfur concrete structure. Numerical implementations of the model are proposed for 3D and 2D structures in Cartesian coordinates. Upon calibration, the model estimates the spatiotemporal distribution of the temperature within the structure based on thermal properties, printing parameters, and environmental conditions. The model is calibrated using experimental data, where the effect of printing parameters is analyzed, and is then utilized to simulate multiple terrestrial and Martian construction scenarios. It identifies a range of printing speeds and interlayer delays that optimize extrudate properties, while also enabling automated control of the thermal C3DP process for optimal performance. 

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2. Analyzing the impact of the aspect ratio of a building on concrete use in its structure

   https://doi.org/10.14311/APP.2022.33.0133  

   Dixit, Manish K.; Pradeep Kumar, Pranav (March 2022, Acta Polytechnica CTU Proceedings)

   Buildings consume over half of annual energy supply as embodied and operating energy in their construction and operation releasing harmful emissions to the atmosphere. Over 90 % of the embodied energy is attributed to construction materials used in building structure, envelope, and interiors that must be reduced to minimize material use. Concrete is one of the major materials that contributes significantly to the energy and carbon footprint of buildings, as it is responsible for 5-9 % of global carbon emission. Because most of the concrete use in the building sector occurs in building structures, assessing how building design parameters influence its environmental sustainability is important. One of the design parameters that impact the sustainability of buildings is the aspect ratio, which is defined as the ratio of horizontal to vertical surface area of a building. A building with the same floor area can be designed horizontally or vertically with different aspect ratios, which will influence its structural design and eventually the amount of concrete used in the building. In this paper, we examine how aspect ratio may affect the environmental sustainability of a buildings foundation, structural framing, and slab. We model the structure of a generic building with different aspect ratio to analyze if aspect ratio can help reduce the energy and carbon embodied in reinforced concrete structures. 

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3. Multivalent Hygrothermal Material System for Double-Skin Envelope Dehumidification Cooling and Daylighting

   Ida, Aletheia (April 2018, Building Enclosure Science and Technology Conference)

   A unique paradox exists between the early and modern architectural and mechanical means of dealing with humidity in and around buildings. Traditional architectural conditions of biopolymeric thatch dwellings accommodated human thermal comfort through dehumidification by the materials employed at the building envelope. Original mechanical developments for dehumidification processes were developed specifically for removing moisture from materials in industrial applications. However, today, the modes by which humidity is treated for human comfort and material protection is inverted: buildings now utilize mechanical conditioning for dehumidification cooling functions and moisture protective materials in the building enclosure systems. Emerging multivalent hydrophilic materials are able to process humidity and moisture transport in new ways to allow for a systemic return to dehumidification cooling functions integrated in the building envelope system. The hydrophilic polymers are synthesized with low energy methods and poured into molds and then lyophilized to create macroporous networks that enhance both the sorption and thermal characteristics in the proposed application. The thermal and optical properties of novel hygrothermal materials are identified and used as inputs for simulation modeling for the proposed multivalent building enclosure system. The initial results provide improvements on annual energy loads and consumption for hot-humid climate conditions (Miami and Mumbai). The introduction of a sorption coefficient for the dehumidification function provides a unique contribution to design and performance analyses of double-skin envelopes. In addition, the dynamic modeling for temporal variations of material properties at the envelope also provides a new contribution to the field of building performance simulation. The challenges of these novel modes for moisture processing in the building envelope materials are addressed, with future work required for microbial identification and monitoring. The advantages from initial analytical and simulation modeling convey improvements for building energy conservation, natural daylighting, and water recuperation potential. 

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4. Control Strategies and Thermal Performance of Responsive Building Envelope with Active Insulation System

   He, Yawen; Fahimi, Farbod; Zhou, Hongyu (January 2022, ASHRAE Buildings XV Conference)

   Thermally dynamic building envelope is a promising technology to achieve building energy saving while improving thermal comfort. Their performance is highly dependent on the local climate conditions as well as on the way the dynamic properties are operated/controlled. The evaluation of whole building performance through building energy simulation can be useful to understand the potentials of different dynamic opaque envelope with active insulations in a specific context. This paper evaluates the potential to use model-free online reinforcement-learning (MFORL) control to regulate the behavior of dynamic building envelopes. Specifically, two control strategies were formulated and evaluated on dynamic opaque envelopes that consist of a concrete layer sandwiched between two active insulations on both sides of the thermal mass: (i) simple temperature-driven rule-based control, and (ii) MFORL control. The controllers were preliminarily tested in two scenarios with 10-day representative behavior under mild climate or during transitional seasons. The results show that MFORL control is promising in achieving adaptive thermal behavior for dynamic building envelopes and may have advantages over traditional rule-based controllers under complex environment. 

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5. Co-Simulation and Validation of Automated Shading Devices using EnergyPlus and Radiance to optimize Building Energy Use

   Vanage, Soham; Kunwar, Niraj; Malekpour, Diba; Cetin, Kristen (January 2022, ASHRAE winter conference papers)

   Buildings in the U.S. are responsible for approximately 40% of energy and 70% of the electricity consumption. To address rising greenhouse gas emissions and climate changes, various studies have explored strategies to reduce energy consumption in buildings. One opportunity to improve the building envelope performance is through improvements to fenestrations, particularly complex multi-layer fenestration systems for exterior windows. Windows are the least thermally efficient of all components in a typical building envelope. Windows also permit solar radiation into a building, which significantly increases the building energy consumption during the summer season. Meanwhile, windows are necessary to provide occupants with natural light, a view to the outside, and to support productivity. Thus, there is a need to strike a balance between energy savings, and the thermal and visual comfort impacted by windows. Traditionally, shading devices are one method used to adjust the amount of heat and light entering an interior space. However, such shading devices are typically operated manually by occupants, and are seldom used effectively over time. Currently the building energy simulation program EnergyPlus, has limited capabilities to model shading devices, and more limited abilities to model dynamic fenestrations. In this study, thus, we propose to model and validate several types of automated multi-layer fenestration elements, using co-simulation of EnergyPlus and Radiance using laboratory-collected data. EnergyPlus was used to model energy consumption and thermal comfort while Radiance was used to model lighting levels. BCVTB was used to interface between EnergyPlus and Radiance to facilitate co-simulation. To validate the models, experimental data was collected from 5 illuminance sensors in an exterior office space located in a test facility in Ankeny, IA. This model methodology can be used to improve the flexibility and modeling capabilities of dynamic fenestration elements for building energy performance evaluation methods. 

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