Thermal parameters of construction assemblies, e.g., the U-values of roofs, walls, floors, ground floors, windows and the solar heat gain coefficient (SHGC) of windows, are significant inputs for ...urban building energy models (UBEMs). However, estimating these values at the urban scale is difficult. A common practice to handle this issue is the use of archetypes. Additionally, there are three approaches in building-level studies, namely, 1) estimation based on technical documents, 2) in-situ measurements, and 3) prediction by machine learning. However, the lack of documentation or long-term testing of physical parameters restricts their applications at the urban scale. This paper presents a non-archetype approach that employs two learning algorithms, i.e., k-means and random forest classification (RFC), to predict thermal parameters of construction assemblies, with several urban & building (UB) factors selected as the inputs. The steps involve: 1) partitioning the thermal parameters in the dataset into k clusters using k-means, 2) assigning a Cluster_ID to the thermal parameters in cluster j and recording its centroid μj, 3) training the RFC, with UB factors as inputs and the Cluster_ID as outputs, 4) predicting the Cluster_ID of thermal parameters of investigated buildings via the trained model, 5) using corresponding centroids as their final thermal parameters, based on the predicted Cluster_ID. As a pilot study, the developed approach has an acceptable result, with the R2 greater than 0.6 and even 0.8. In addition, the study also introduces approaches for acquiring UB factors at the urban scale and demonstrates a case study in Nanjing.
•The relationship between thermal parameters and urban & building factors is analyzed.•Machine learning is employed to objectively reflect the relationship.•The algorithms and methods for acquiring urban & building factors are introduced.•The approach is in a non-archetype way that can predict the values for each building.
•Established a BIM based approach to evaluate building lifecycle energy.•Embodied energy cost for saving one unit of operating energy is computed as EE factor.•EE factor quantifies trade-offs between ...embodied and operating energy components of a building.•The climate zone, amount and type of material, and the operating energy savings influences the EE factor.
Annually, 48% of the global energy is used by buildings in their construction, operation, and maintenance, causing significant damage to the environment due to the resulting greenhouse gas emissions. During their life cycles, buildings use energy in the form of embodied energy (EE) and operating energy (OE). In a conventional building, EE accounts for 10–20% of a building’s life cycle energy (LCE), while OE accounts for 80–90%. As a result, the building sector has taken several measures to reduce OE in buildings. These OE reducing measures fail to account for the subsequent increase in EE and might cause an increase in the building’s overall LCE. A systematic review of the literature shows limited research that comprehensively evaluates the impact of design measures aimed at OE reduction on EE for different construction assemblies. In this study, we quantify and compare trade-offs on EE demand, caused by OE reduction measuresfor eight different building wall assemblies across four climatic zones within the United States. The EE and OE demands of the ASHRAE 90.1–2016 benchmark model and its variations were computed using Tally™ and Autodesk® Green Building Studio® (GBS), respectively. The results helped us determine the EE factor (EE spent per unit of OE savings) for different OE reduction measures. Although the calculated EE factors vary across different climatic zones and construction assemblies, these factors show significant EE costs for different OE reduction measures. This knowledge could help inform the design of evolutionary and deep/machine learning-based algorithms to assess and optimize building energy use.
Purpose
New methods to introduce topics in classrooms are needed to enhance the construction management educational experience. One of these new methods is showing real time videos that highlight the ...various elements of concern in the classroom lecture. The purpose of this paper is to use augmented reality technology (ART) and a layer of artificial visualizations to simulate the environmental context and spatio-temporal constraints of various construction processes. The superimposition of images serves as an instructional mechanism to virtually incorporate jobsite experiences into classrooms. This enhancement of spatio-temporal constraints enables learners to visualize context and hidden processes otherwise unattainable through traditional classroom lectures.
Design/methodology/approach
A significantly improved perception of reality is created through the combination of the learners’ ability to understand the complexity of construction products (e.g. assemblies) and associated jobsite processes by viewing the real environment augmented with computer-generated information layers.
Findings
Testing the ART video in a classroom with undergraduate construction management students showed that students who were exposed to the ART video were able to remember and identify the highlighted elements in the corresponding assembly more effectively than those who were not.
Originality/value
ART is a valuable tool in enhancing classroom learning and gives educators a teaching advantage when they combine traditional classroom lectures with ART enabled media.
Building environmental design typically focuses on improvements to operational efficiencies such as building thermal performance and system efficiency. Often the impacts occurring across the other ...stages of a building's life are not considered or are seen as insignificant in comparison. However, previous research shows that embodied impacts can be just as important. There is limited consistent and comprehensive information available for building designers to make informed decisions in this area. Often the information that is available is from disparate sources, which makes comparison of alternative solutions unreliable. It is also important to ensure that strategies to reduce environmental impacts from one life cycle stage do not come at the expense of an increase in overall life-cycle impacts. A consistent and comprehensive framework for assessing and specifying building assemblies for enhanced environmental outcomes does not currently exist. This article presents the initial findings of a project that aims to establish a database of life cycle energy requirements for a broad range of construction assemblies, based on a comprehensive assessment framework. Life cycle energy requirements have been calculated for eight residential construction assemblies integrating an innovative embodied energy assessment technique with thermal performance modelling and ranked according to their performance.
Throughout the years, various teaching methods have been adopted to assist students to better understand building assemblies and construction details. Many current teaching techniques for explaining ...building assemblies use various mediums such as 2D drawings, isometric and perspective drawings, photographs of assemblies and also field trips to the construction jobsite. Such detail needs to be complemented with plans, elevations and sections. This is necessary because in any drawing only 2 dimensions are visible. 3D CAD modeling addresses the third dimension that is not present in 2D CAD drawings, and allows better viewing, validating and understanding building components and their construction. This paper addresses the impact of using 3D in teaching and its advantages over current approaches. The paper describes a pilot study conducted with students from the Virginia Tech Architecture and Building Construction departments. The experiment investigated the advantages of 3D representation as compared to 2D drawings, in understanding construction assemblies and details. The paper also discusses the shortcomings of the traditional methods and compares the suitability of using 3D as a teaching aid. A new approach utilizing pocket PCs and/or laptop computers via wireless connectivity, to allow students to access and view 3D models remotely, is briefly presented.
There is a growing interest in exploring the use of wearable Augmented Reality (AR) devices to improve the task performance of construction workers. However, user interaction with AR has not been ...well understood in the current literature, which may result in poor usability, occupational hazards, and low acceptance. To bridge this gap, this study introduced cognitive ergonomics theory to design and develop an AR application for improving the kinaesthetic performance of construction workers conducting onsite assembly tasks. The methodology of this study is three-fold. First, articles in relation to cognitive ergonomics were reviewed to propose a unique cognitive model that reveals the cognitive mechanisms of construction workers, including human information processing, selective attention, and attention resources. Second, the characteristics of existing AR application functions were synthesised to develop a customised and user-friendly wearable AR application that aligns with the identified cognitive mechanisms. Third, a rebar-tying experiment was conducted to validate the developed AR application. The results indicate that the experimenters instructed by the application can complete the task independently without the need to seek after expert assistance; the application has a potential to foster the skill development of construction workers and enhance their kinaesthetic performance; and the proposed cognitive model and the AR development principles are well aligned from the perspective of cognitive ergonomics, which could promote the uptake of wearable AR in the construction industry.
•Cognitive ergonomics theories were introduced to design and develop the AR application.•A cognitive model was proposed to reveal the impact of the application on construction worker performance.•The development assisted the workers in assembling rebars more independently.•The kinaesthetic performance of workers significantly increased as well.
Augmented Reality Head-Mounted Displays (AR HMD) are considered a promising technology for assisting on-site construction tasks such as assembly. However, concerns about creating information overload ...and becoming a distraction to workers outweigh the potential benefits to productivity and task performance. Previous research investigated workers' mental workloads as impacted by AR-based displays for assembly tasks. Within that context, this paper proposes a Long Short-Term Memory (LSTM) based approach to predict mental workload when using AR HMD for construction assembly, to forecast users' cognitive status under such complex working condition. Thirty participants were recruited to finish a wood frame assembly using an AR HMD projecting a 3D conformal model on the workspace. The proposed method provided a reliable prediction of real-time electroencephalogram (EEG) signal and mental workload. The outcomes validated the feasibility of LSTM model for EEG-based mental workload prediction and specifically provided a usable method for evaluating AR HMD use in construction tasks.
•Discussed the benefits of predicting mental workload while using AR-HMD in construction assembly tasks.•Conducted an AR-based assembly test with 30 subjects to explore mental workload oscillations and feasibility of prediction.•A deep learning approach was deployed to forecast the raw EEG data and predict subjects' mental workload.•The performance of proposed LSTM model was compared with other commonly used RNNs.
Offline programming (OLP) is a mainstream approach for controlling assembly robots at construction sites. However, existing methods are tailored to specific assembly tasks and workflows, and thus ...lack flexibility. Additionally, the emerging large language model (LLM)-based OLP cannot effectively handle the code logic of robot programming. Thus, this paper addresses the question: How can robot control programs be generated effectively and accurately for diverse construction assembly tasks using LLM techniques? This paper describes a closed user-on-the-loop control framework for construction assembly robots based on LLM techniques. A hierarchical strategy to generate robot control programs is proposed to logically integrate code generation at high and low levels. Additionally, customized application programming interfaces and a chain of action are combined to enhance the LLM's understanding of assembly action logic. An assembly task set was designed to evaluate the feasibility and reliability of the proposed approach. The results show that the proposed approach (1) is widely applicable to diverse assembly tasks, and (2) can improve the quality of the generated code by decreasing the number of errors. Our approach facilitates the automation of construction assembly tasks by simplifying the robot control process.
•A closed user-on-the-loop construction assembly robot control framework based on LLM techniques is developed.•A hierarchical robot control program generation strategy is proposed.•Customized APIs and Chain of Action are combined to enhance LLM's understanding of assembly action logic.•The proposed approach is widely applicable to diverse assembly tasks.•The proposed approach can improve the quality of generated code by decreasing the number of errors.
Three-dimensional imagery derived from a building information model (BIM) based virtual prototype can be used to non-verbally communicate constructability information. This paper describes an ...assessment of using instructive pictographs to characterize prefigured assembly information for construction assembly procedure. It employs industry-recognized virtual prototyping software to model the assembly configuration of a real world mobile test laboratory. The findings of the research show that virtual prototyping as an nd-BIM technology has the potential to better integrate architecture, engineering and construction (AEC) information to project delivery with user-specific constructability knowledge.
•Virtual prototyping (VP) is defined as an nd-BIM technology integrating AEC.•VP can be used to leverage user-specific knowledge that informs project delivery.•Pictographic instruction derived from a pre-figured VP assembly model is assessed.•Imagery from VP assembly scenarios can be used to communicate constructability.
Some notes for the history of rain-screen wall Madrid, Joaquín Fernández
Construction history : journal of the Construction History Group,
01/2020, Volume:
35, Issue:
2
Journal Article
Peer reviewed
This paper presents the state-of-the-art construction technology from the 1950s and 1960s (in western architecture) for the prevention of water ingress through building façades, as well as more ...traditional construction solutions that can be considered antecedents of the ventilated façade. Three different construction systems have been combined in the development of the rainscreen wall as a new independent façade system. The tabique pluvial, the cavity wall and the curtain wall, successively provided the mechanisms to control water ingress and condensation in a façade exposed to wind driven rain.
This paper offers some case study examples - Crane (1952), Rogers (1955), Ortiz Echagüe (1956), Schaal (1961), Eichler (1969) - which exemplify the state-of-the-art technical solutions to protect façades against water, not always with the same purpose, but with designs very close to a ventilated façade. Finally, a careful chronology is established which helps to order the contributions of specialists and professionals from different cultures, who helped the invention of the ventilated façade as a new and definitive construction assembly.
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