On-site Construction Processes Research Articles

Research on flexural behavior and design method of formwork free UHPC wet joint in prefabricated small box girder bridges

This study aims to enhance the bearing capacity of wet joints in prefabricated small box girder bridges while simplifying the on-site construction process. Experimental tests were conducted on formwork-free ultra-high-performance concrete (UHPC) wet joints, focusing on failure modes, ultimate flexural capacities, and cracking and strain behaviors. These were compared to the behaviors observed in rectangular and funnel-shaped wet joints. The results demonstrate that the width of the joint significantly influences flexural performance, with the horizontal strip playing a crucial role in resisting cracks. It is recommended that for formwork-free UHPC wet joints, the strip height h2 should be no less than 0.1 times the thickness of the bridge deck, and the joint width W should be at least eight times the diameter of the transverse steel reinforcement. Considering the contribution of UHPC in the tensile zone, formulas were developed to calculate the flexural capacity of UHPC-normal concrete (NC) composite section beams. Based on these flexural test results and numerical analysis, a design method for formwork-free UHPC wet joints is proposed.

Building Digital Twins to Overcome Digitalization Barriers for Automating Construction Site Management

Construction sites are highly unpredictable environments involving a wide variety of stakeholders with complex information exchanges, which lead to the well-known inefficiencies and unproductivity of the construction sector. The adoption of Building Digital Twins (BDT) in the construction site is a promising solution to this issue, by automating data acquisition and knowledge extraction processes and providing what-if scenario simulation capabilities. Furthermore, the current research sets the principles to define, replicate, and scale-up the architecture of a Building Digital Twin Platform (BDTP), conceived as a scalar ecosystem, which allows to seamlessly manage on-site construction processes, integrating cross-cutting domains for the construction site optimization (Progress monitoring, Quality control, Operational Health and Safety, Equipment control, and Production planning). The starting point of the research is a comprehensive diagnosis of on-site process inefficiencies and the barriers to its digitalization leading to the user requirements, which have been underpinned by questionnaires and interviews addressed within an open innovation user-centered approach around Living Labs. The research has been conceived following the Design Science Research (DSR) methodology and based on the Plan-Do-Check-Act (PDCA) analysis for the continuous improvement of the construction process. By means of the adoption of the standard Business Process Model and Notation (BPMN), based on the BDTP architecture, the research has resulted in BPMN workflows stemmed from the Digital Twin (DT) where the DT itself is an actor in a service-oriented data-exchange workflow. Moreover, the use of a BDTP can pave the way for the transition from user-driven construction management to hybrid management, coexisting with both human and digital actors and merging expert knowledge with artificial intelligence techniques.

Sustainability Performance in On-Site Construction Processes: A Systematic Literature Review

One of the most important challenges in the construction industry is to develop projects covering all three dimensions of sustainability: economic, social, and environmental. However, the construction project management literature lacks clarity regarding the fundamental principles and effective strategies for implementing sustainability for on-site construction processes. This article provides a comprehensive analysis of the sustainability dimensions in the construction sector, highlighting sustainability key performance indicators (KPIs) for on-site practices. The analysis stems from a systematic literature review sourced from the Web of Science and Scopus databases. The search identified 17 environmental, 20 social, and 15 economic indicators, with the most relevant being those associated with key terms such as cost, profit, labor, customer satisfaction, community impact, resource utilization, and contaminant management. The theoretical implications of this study contribute a critical framework for integrating the sustainability dimensions into construction practices, advancing the industry’s sustainability. For practitioners, the findings offer a prioritized guide to enhance on-site construction processes (O-SCP) sustainability and provide measurable KPIs for tracking progress toward sustainable development goals. This study not only sheds light on the current application of sustainability in O-SCP but also paves the way for future research to further this field.

Optimizing the Integration of Building Information Modelling using Response Spectrum and Linear Time History Analysis. Case Study: Irregular Hangar Structure

The increasing use of technology in the construction industry has introduced the concept of Building Information Modeling (BIM), which is widely utilized to streamline construction activities. BIM enables the exchange of data across various disciplines quickly, as well as facilitates analysis, design, and on-site construction processes. The implementation of BIM will be carried out in the analysis and design processes of structures with irregularities to assess the effectiveness and performance of BIM in modeling and analyzing structures. Considering the burgeoning development of the construction industry in Indonesia, there is a necessity for a laboratory hangar dedicated to conducting structural model tests and construction material examinations. The aim of this study is to compare the response and the volume output between the response spectrum and linear time history analysis of an irregular structure. The case study conducted in this research focuses on the 5-stories Laboratory Hangar in Indonesia. The software used in this study includes Autodesk Revit 2023 for BIM modeling and ETABS V21 for structural analysis. Data and model exchange are performed between both software platforms to evaluate the BIM integration between them.

Investigation of Uniaxial Compression Stress–Strain Relationship of Early Age Manufactured Sand Concrete and Its Application

To improve the construction efficiency of the manufactured sand concrete engineering at an early age, the uniaxial compressive stress–strain relationship of C50 manufactured sand concrete is investigated starting at 2 days to 28 days. With the characteristics of the stress–strain relationship, the uniaxial compression constitutive model is determined for the C50 manufactured sand concrete at early age. The influence of age, water-to-binder ratio, and fly ash admixture on the peak stress and peak strain of manufactured sand concrete is analyzed for the parameters of the constitutive model. Results show that the stress–strain curve of manufactured sand concrete is essentially similar to that of ordinary concrete. Via six typical constitutive models, the Sargin model produced the best fitting: its R2 mean is 0.9775, MAE mean is 0.1335, and MSE mean is 0.0175. Considering the influence of different factors, the early age uniaxial compressive constitutive models of manufactured sand concrete were proposed based on the Sargin model. Combined with the on-site construction process of the high pier formwork climb, the finite element analysis was carried out using the proposed early age uniaxial compressive constitutive model. Compared with the measured results of strain near the climbing cone, the error was less than 10% from the simulated value. The findings confirm that the proposed early age uniaxial compressive constitutive model presents great reasonableness for the manufactured sand concrete construction at an early age.

Tracking indoor construction progress by deep-learning-based analysis of site surveillance video

Purpose Accurate and rapid tracking and counting of building materials are crucial in managing on-site construction processes and evaluating their progress. Such processes are typically conducted by visual inspection, making them time-consuming and error prone. This paper aims to propose a video-based deep-learning approach to the automated detection and counting of building materials. Design/methodology/approach A framework for accurately counting building materials at indoor construction sites with low light levels was developed using state-of-the-art deep learning methods. An existing object-detection model, the You Only Look Once version 4 (YOLO v4) algorithm, was adapted to achieve rapid convergence and accurate detection of materials and site operatives. Then, DenseNet was deployed to recognise these objects. Finally, a material-counting module based on morphology operations and the Hough transform was applied to automatically count stacks of building materials. Findings The proposed approach was tested by counting site operatives and stacks of elevated floor tiles in video footage from a real indoor construction site. The proposed YOLO v4 object-detection system provided higher average accuracy within a shorter time than the traditional YOLO v4 approach. Originality/value The proposed framework makes it feasible to separately monitor stockpiled, installed and waste materials in low-light construction environments. The improved YOLO v4 detection method is superior to the current YOLO v4 approach and advances the existing object detection algorithm. This framework can potentially reduce the time required to track construction progress and count materials, thereby increasing the efficiency of work-in-progress evaluation. It also exhibits great potential for developing a more reliable system for monitoring construction materials and activities.

Investigation on the deformation and energy dissipation behaviors for foamed concrete filled polyethylene pipe under quasi-static axial compression

The long-term curing and defoaming issues within large volume foamed concrete during the on-site construction process could be efficiently resolved by fabricated foamed concrete filled polyethylene (FC-PE) pipes, which have significant potential for geotechnical and tunneling engineering for the design of large deformation and dynamic disaster. However, it is still unknown how filling action will affect FC-PE pipes that are subjected to axial load in terms of deformation and energy absorption. In this study, the FC-PE pipe and its individual components were investigated experimentally and theoretically. Results show that the initial peak load effect of FC-PE pipe is not particularly noticeable and the fluctuations of compression load are nearly periodic and uniform. In contrast to the individual components combined separately, the interaction of polyethylene pipe and foamed concrete filler can significantly increase the energy absorption capacity by more than 2.5 times. Given the dimensions of the polyethylene pipe, the effect of the foamed concrete density has a roughly linear positive correlation with the total energy absorption, the effective energy absorption, and the mean crushing force, whereas the densification displacement and the undulation of load-carrying capacity are in opposition. Based on the principle of energy, the theoretical mean crushing force FC-PE pipe was deduced accounting for the effective folding angle of the pipe wall and the interaction effect and their interaction, which of the corresponding errors of theory and experiment were between 11.8 and 17.7%.

Qualitative and quantitative study to assess the use of rammed earth construction technology in Perth and the south-west of Western Australia

During the last decades, rammed earth technology has been explored worldwide because of a growing concern for sustainable constructions. A relevant, contemporary technical culture of rammed earth developed in the south-west of Western Australia (WA) from the 1970 s. Several examples of residential, educational, commercial and community buildings in the region were built in rammed earth during the last 40 years. An active group of professionals involved in rammed earth construction operates in the region. This study assesses the state of the art of rammed earth construction practice in the south-west of WA based upon a qualitative and quantitative questionnaire to the professionals involved in the local rammed earth construction industry. The questionnaire collects data on five major technical areas: (i) strengths and weaknesses of rammed earth technology; (ii) opportunities and deterrents to employ rammed earth in the south-west of WA; (iii) rammed earth materials and on-site equipment and construction process; (iv) aesthetic and design qualities of rammed earth buildings; and (v) thermal performance of rammed earth buildings. The study's objective is to analyse the potential of the rammed earth technology within the local construction sector, engaging the local industry to identify the paths for further development of the current guidelines.

Nexus between Building Information Modeling and Internet of Things in the Construction Industries

The process of integrating building information modeling (BIM) and Internet of Things (IoT)-based data sources is a recent development. As a generalization, BIM and IoT data provide complementary perspectives on the project that complement each other’s constraints. Applying the concept of BIM-IoT in the construction industries which has been termed to have a high-risk factor could offer an improvement in the overall performance of the construction industries and thereby reduce the associated risks. This study aims to examine the potential of integrating BIM-IoTs in the construction industries by examining related published literature. Literature analysis revealed that the BIM and IoT have been extensively applied individually to several aspects of construction projects such as construction safety risk assessment, construction conflict management, building construction sustainability, and onsite construction process monitoring. However, there is scanty research awareness on the possibilities of BIM-IoT integration in the construction industries.

Analysis of Roof Stability of Coal Roadway Heading Face

One of the challenges that urgently needs to be addressed, both in current times and in the future, is to improve the heading speed of coal roadways. The roof instability of the heading face is the main factor restricting the rapid heading of coal roadways. Based on the theory of thin plate, a mechanical model of the roof in the heading face is established, the distribution law of deflection, stress, and internal force is discussed, and the supporting principle of the roof is clarified. Through a Flac3D numerical simulation, the main influencing factors of roof stability in the heading face are analyzed, including ground stress, surrounding rock strength, roadway section, unsupported distance, etc., and the regression analysis of each factor is carried out by evaluating the amount of roof subsidence. The results show that the maximum tensile stress and the corresponding bending moment of the roof appear at the fixed supported edge, and the maximum compressive stress and the maximum value of the corresponding bending moment appear at the center of the roof slightly close to the simply supported edge. In the on-site construction process, the position close to the fixed supported edge needs to be supported first. The roof subsidence has a positive exponential relationship with the stress level, a negative exponential relationship with the surrounding rock strength, a quadratic functional relationship with the roadway section, and a logarithmic relationship with the unsupported distance. In fractional support, the initial partial support can timely reduce the roof span and partially recover the confining pressure. Under certain geological and production conditions, the use of fractional support can not only effectively maintain the stability of the roadway but also speed up the heading speed. According to the research results, it is determined that in the auxiliary transportation roadway of the Caojiatan Coal Mine, the 122,110 working face adopts the fractional support model, the maximum roof subsidence is 18 mm, the roof is stable, and the monthly progress is more than 1000 m, which significantly improves the roadway heading speed.

Optimization of assembly sequence of building components based on simulated annealing genetic algorithm

A large number of prefabricated components are composed of different types of houses. The on-site assembly sequence of components is also the key link of the construction organization of the project. The assembly sequence obtained by manual experience is easy to omit components and interfere with each other. According to the weight and assembly process of construction components, the evaluation index of mechanical assembly process is introduced to clarify the relationship between the number of components and the assembly process. In the aspect of intelligent optimization algorithm, the simulated annealing program module is introduced into the existing genetic algorithm to form a new simulated annealing genetic algorithm. The comparative study of the calculation results shows that the simulated annealing genetic algorithm can search the global optimal assembly sequence scheme more accurately and efficiently, and meet the evaluation indexes at the same time. The mechanical simulation technology is innovatively used to simulate the assembly of building components, and the simulation process is used to guide the on-site construction process.

Construction Technology and Engineering Application of Post Installation of Concrete Decorative Lines on Building Facades

For the consideration of beautiful appearance of building facades, many building facades are designed with reinforced concrete lines. The traditional building facade concrete decorative line needs secondary pouring construction, which has the problems of complex construction process, low construction precision, high construction cost and poor construction quality. This paper presents a construction method of post installation of concrete decorative lines on building facades. Firstly, the principle of post installation of concrete decorative lines on building facades is clarified by theoretical analysis method, then the design and calculation method of decorative lines is clarified by mechanical analysis method, and then the specific construction process of decorative lines is clarified in combination with the on-site construction process. Finally, the post installation construction technology of concrete decorative lines on building facades is applied to a project example, and the economic analysis is carried out. The results show that the post installation of concrete decorative lines on the building facade is mainly based on the construction principle of prefabricated installation; The stress analysis of decorative lines needs to focus on the strength of the connectors between the lines and the building structure; Compared with the traditional secondary pouring construction method of decorative lines, the post installation construction method can save about 30% of the cost, and the construction process is more safe and efficient, with higher construction precision and quality. It is suggested that it can be popularized and applied in similar projects.

Experimental study on seismic behavior of precast concrete beam-column joints using UHPC-based connections

Ultra-high performance concrete (UHPC) with high bond characteristics with reinforcing bars could significantly shorten the lap splice length of rebars. UHPC-based rebar lap splice connections offer larger tolerance and simpler operation than traditional rebar connection approaches, which could ease and accelerate the on-site construction process of precast concrete structures. This paper characterizes the seismic behavior of precast beam-column joints where the longitudinal rebars of columns are connected using UHPC with a lap length of 15 times rebar diameter (15db). Full-scaled cyclic tests on two precast joints and two corresponding monolithic joints to compare were carried out keeping a high axial compression ratio (n) at 0.5. It was demonstrated that the beam-column subassemblies failed characterized by flexural failure of beam end instead of the column or joint core. The arch-like load–displacement curves and stable hysteretic behavior were still captured considering the p-delta effect. The proposed precast beam-column joints with UHPC-based connections could achieve similar bearing capacity, ductility and stiffness degradation rule to the monolithic counterparts. The degenerated four-linear restoring force model was presented and verified. Moreover, the numerical simulation was also performed, and the predicted structural behavior was in agreement with the experimental results.

Seismic performance of full-scale UHPC-jacket-strengthened RC columns under high axial loads

Ultra-high-performance concrete (UHPC) is a class of concrete materials that have high strength and ductility capacities. This study developed two UHPC jacketing methods to improve the seismic performance of shear-deficient RC columns in mid- to high-rise buildings without enlarging the cross-section of the columns. In the first method, the original concrete cover was replaced with a cast-in-place UHPC jacket that was reinforced by steel bar mesh. To simplify the on-site construction process, the second method utilized prefabricated UHPC panels incorporating steel bar mesh. The performance of the proposed strengthening methods was evaluated using cyclic loading tests on three full-scale RC columns with a high axial load demand. The test results showed that the developed UHPC jacketing methods improved the lateral strength and drift capacity of the shear-deficient column by at least 40% and 30%, respectively. They also reduced the residual displacement of the column by 65%-80%. Compared to the cast-in-place jacketing, the discontinuity in the prefabricated UHPC jackets inhibited full composite action of the jacketing, thus reducing the retrofitting efficiency. In addition to the experimental study, evaluation methods were proposed to evaluate the strength and behavior of the retrofitted columns.

Study on the Influence of Close Distance Construction of Urban Tunnel on the Existing Station

In the construction of the tunnel passing through the existing structure at an ultra-close distance, the existing structure will produce obvious deformation. It is very important to understand the deformation characteristics of the existing upper structure at different positions, especially to ensure the safety of the upper structure and improve the effectiveness of tunnel construction. In this study, the double-line tunnels of Qingdao Metro Line 4 passing under the Cuobuling station were taken as the engineering background, and a detailed 3D numerical model was established. This study comprehensively considered the on-site construction process, including grouting hardening, stress release of the excavated rock mass, grouting pressure and so on. The influence of tunnel excavation on the ground settlement was compared with or without a station structure, and the result was fitted with an empirical formula. Finally, the deformation of the station structure due to the excavation of the double-line tunnels was analyzed. The results of the analysis were as follows: (1) In the presence of the station structure, the excavation of the tunnels had a significant impact on the surface settlement. (2) The settlement of the sidewall caused by the excavation of the left-line tunnel was greater than that of the right-line tunnel, and the settlement at the junction of the sidewall and the bottom plate was smaller than that at other positions of the sidewall. (3) Compared with the roof and middle slabs, the floor of the station was more susceptible to the influence of tunnel excavation. Overall, the research could provide guidance and reference for similar double-line tunnels through existing stations.

Estimating on-site emissions during ready mixed concrete (RMC) delivery: A methodology

Sustainability represents a critical challenge in the construction industry and many approaches have been developed to reduce the environmental impact of on-site construction processes. However, scant academic attention has been given to the environmental impact of logistical support for ready mixed concrete (RMC) on-site delivery emissions in developing countries. This paper develops a methodology for capturing emissions from RMC equipment and material during on-site delivery operations. A literature review was conducted to define and delineate upon greenhouse gases emitted during RMC operations and the appropriate methods to calculate them. A methodology was then developed and validated by analysing ten delivery cycle times in a case study. Data collected was analysed using simple descriptive summary statistics (viz: mean, bar charts and standard deviation). The study’s results illustrate that on-site emissions incurred were: CO2 account for 99.38 % of the total emissions from RMC equipment while HC (0.03 %), CO (0.11 %), NOx (0.26 %), PM10 (0.02 %), and SO2 (0.20 %) account for 0.62 %. Embodied CO2 in RMC also contributes majorly to emissions in on-site delivery operations. Alternative materials such as fly ash represent a viable means of reducing embodied emissions in RMC but proper handling is required to avert harmful environmental impacts. The study provides deeper insights into the on-site emissions arising from RMC delivery operations and a bespoke methodology that could be used as an organisational learning tool for RMC companies.

Production Metrics for Planning Structural Drafting Operations for Reinforced Concrete Staircases in Structural Firms within Uganda

Productivity and production rate benchmarks for labor and equipment in the construction sector are vital metrics used to support comprehensive project planning and control activities. Scheduling and budgeting are the two project planning processes that utilize these metrics in their development and use. There is a misconception that project planning and control processes are mainly undertaken by the contractors for construction process but not by consultants for their analysis, design, and drafting processes. Interactions with practitioners serving in supervisory roles in consulting firms so the need and desire to perform these operations too, so that they are furnished with timeline and cost information to better plan and manage their tasks. However, most research activity has been directed towards obtaining benchmarks related to onsite construction processes leaving those in analysis, design, and drafting clueless about what possible benchmarks for their activities are. This study set out to measure and benchmark structural drafting operations for reinforced concrete staircases. Time measurements were done for two of the different types of reinforced concrete staircase configurations, i.e. straight-run and spiral staircases and benchmarks proposed for each of those types. Keywords: Productivity, production rate, benchmarks, reinforced concrete staircases, structural drafting DOI: 10.7176/CER/12-5-02 Publication date: May 31 st 2020

Investigating the Relationship between Site Supervision and IBS Based Construction Projects

Successful delivery of construction of Industrialized Building System (IBS) projects needs an effective supervisor’s that have a combination of strong technical, interpersonal, communication, and managerial skills. Unfortunately, a consistent finding is that there are many factors that affecting site supervision and most construction works are not delivered on time and consequently have a problem during installation of IBS. Therefore, the main aim of the study is to identify the factors affecting site supervision in improving IBS productivity. The study adopts a questionnaire survey approach to elicit information from the respondents, and out of the seventy questionnaires administered fifty-five were retrieved. The information and the data from the questionnaires were analyzed using the average index method. From the finding analysis, the main factors affecting site supervision is on-site construction process. While the main problem during installation of IBS is required planning on time delivery. It is recommended that the quality of IBS product or components should be enhanced to promote better site supervision

BIM-based energy consumption assessment of the on-site construction of building structural systems

PurposeSteel and reinforced concrete are among the most common structural materials used in the construction industry. Cost and the speed of construction have been usually the main criteria when selecting a building’s structural system, whereby the environmental impact of the structural material is sometimes ignored. Availability of an easy-to-use tool for environmental assessment of the structural alternatives could encourage this evaluation in the decision making. The purpose of this paper is to introduce an automated tool for the environmental assessment of the on-site construction processes of a building structural system, which calculates the energy consumption and carbon emissions of the structural system as a parameter for comparison.Design/methodology/approachThis assessment tool is implemented using a building information modeling (BIM) platform to extract structural elements and their key attributes, such as type, geometrical and locational data. These data are processed together with a productivity database to calculate machine hours, and then predefined energy and carbon inventories are used to assess the energy consumption of the structural system in the erection/installation stage.FindingsThis assessment tool provides an automated and easy-to-use approach to estimate energy consumption and carbon emissions of different structural systems that are modeled in a BIM platform. The results of this tool were within the ranges reported by the available studies.Originality/valueThis research project presents a novel approach to use BIM-based attributes of the structural elements to calculate the required efforts, i.e. machine hours, and assess their energy consumption and carbon emissions during construction processes.

Evaluation of Terrestrial and Mobile Scanner Technologies for Part-Built Information Modeling

AbstractThe focus of this paper is on the relatively under explored area of partially completed (part-built) information modeling because this can assist during on-site construction processes. Addi...