Scalability is a problem common to most existing 3D printing processes, where the size of the design is strictly constrained by the chamber volume of the 3D printer. This issue is more pronounced in ...the building and construction industry, where it is impractical to have printers that are larger than actual buildings. One workaround consists in printing smaller pieces, which can then be assembled on-site. This workaround generates however additional design and process complexities, as well as creates potential weaknesses at the assembly interfaces. In this paper, we propose a 3D printing system that employs multiple mobile robots printing concurrently a large, single-piece, structure. We present our system in detail, and report simulation and experimental results. To our knowledge, this is the first physical demonstration of large-scale, concurrent, 3D printing of a concrete structure by multiple mobile robots.
•Use multiple mobile robot printers in multi-agent settings for collaborative printing•System incorporates localisation, collision avoidance and optimal robot placement•Improve scalability and time efficiency, and demonstrate on-site printing capability•Large structure printed with proposed system in a safe, efficient and scalable manner•First multi-robot simultaneous printing on single concrete structure
Accurate building construction cost prediction is critical, especially for sustainable projects (i.e., green buildings). Green building construction contracts are relatively new to the construction ...industry, where stakeholders have limited experience in contract cost estimation. Unlike conventional building construction, green buildings are designed to utilize new technologies to reduce their operations’ environmental and societal impacts. Consequently, green buildings’ construction bidding and awarding processes have become more complicated due to difficulties forecasting the initial construction costs and setting integrated selection criteria for the winning bidders. Thus, robust green building cost prediction modeling is essential to provide stakeholders with an initial construction cost benchmark to enhance decision-making. The current study presents machine learning-based algorithms, including extreme gradient boosting (XGBOOST), deep neural network (DNN), and random forest (RF), to predict green building costs. The proposed models are designed to consider the influence of soft and hard cost-related attributes. Evaluation metrics (i.e., MAE, MSE, MAPE, and R2) are applied to evaluate and compare the developed algorithms’ accuracy. XGBOOST provided the highest accuracy of 0.96 compared to 0.91 for the DNN, followed by RF with an accuracy of 0.87. The proposed machine learning models can be utilized as a decision support tool for construction project managers and practitioners to advance automation as a coherent field of research within the green construction industry.
Reply Ruiseñor Vázquez, Pablo R; Galletti, Jonatán David; Mínguez, Natalia ...
American journal of ophthalmology,
01/2015, Volume:
159, Issue:
1
Journal Article
Peer reviewed
The optimal cutoff value (defined as that closest to the perfect classification point in the curve) was >5 m for front elevation (78% sensitivity, 94% specificity) and >10 m for back elevation (82% ...sensitivity, 91% specificity).
Building Information Modelling (BIM) paved the way to better information management in the construction sector, simplifying and encouraging the advent of digital technologies and tools. The ...application of large-scale additive manufacturing (AM) is growing and therefore subject to intensive research – on account of its disruptive potential to revolutionise the Architecture, Engineering and Construction (AEC) industry.
With this systematic literature review, the authors aim to identify the major advances made so far on AM's applicability to the construction sector, with particular attention being given to the thermal efficiency of 3D printed buildings.
The article begins by presenting the review methodology applied and offering an outline of the current situation in the construction industry, followed by a discussion on different AM processes. Applications in the construction industry are presented and the development of extrudable materials is addressed. The influence of the thermal insulation of the building's envelope on its energy consumption is explained and experimental applications presented.
The state-of-the-art shows that 3D printing (3DP) is still in an early stage and the research remains focused on the printability and structural capacity. There is a noticeable gap on physical aspects such as thermal and acoustic behaviour, which are of major importance to the indoor environment quality. By discussing the difference in performance between commercial thermal insulation materials and the existing 3D printed materials, this research outlines new ways of improving the thermal performance of 3D printed structures, by using additives in the printed mix or by acting on the wall's structure.
•3DP lowers construction's environmental impact and stimulates circularity.•Material, printing process, design and function are significantly interdependent.•Thermal insulation affects the building's indoor temperature and energy demand.•Material extrusion is the main process currently applied to 3D print concrete.•Research on the thermal performance of 3D printed structures is needed.
The ebook edition of this title is Open Access and freely available to read online. Specification for Tunnelling, Fourth edition is a standard industry document for tunnelling contracts and forms the ...basis of tunnelling specifications for projects throughout the world. It reflects current industry best practice and considers technological advancements over the last ten years. It also investigates a range of new topics. Since the publication of the third edition in 2010, the British tunnelling industry has completed several major projects both domestic and abroad. This updated fourth edition captures the many advances made in the field of tunnelling and the lessons learned on these projects through a comprehensive review of all content by subject matter experts. The importance of sustainability and the increased market share of low CO2e materials have been reflected by removal of prescriptive requirements and a strong emphasis on performance-based specification. All references to codes, standards and other design documents have been comprehensively updated. Drafted by an expert editorial committee and supported by multiple rounds of industry-wide peer reviews, the Specification for Tunnelling in its fourth edition will continue to be the de facto standard reference work for tunnelling in the UK and worldwide.
This research aims to find out the effectiveness of the use of multimedia-based learning media in building construction courses I. The research method used is quasi experimental with a randomized ...form of pretest-posttest control group design. Data collection is done with pretest and posttest instruments given to two classes of experiments and controls. The results of this study are derived from the Whitney U-Mann test and the N-gain test, which showed that there was a significant difference between the results of the experimental class learning and the control class, and there was an increase in learning outcomes with intervals of 56%-76% in column material, plate material, window door sill material, ladder material, and roofing materials. As a result, the use of multimedia learning materials in these materials is effective for online learning in building construction courses.
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