Keywords

8.1 Key Definitions and Concepts

Table 8.1 provides a summary of key definitions and concepts related to the use of intelligent construction equipment and robotics in the construction industry.

Table 8.1 Key definitions and concepts
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8.2 Introduction

The construction industry plays a crucial role in ensuring job creation, driving economic growth, and providing solutions to address environmental, social, and economic challenges. The market value of the construction sector represents between 9% and 15% of GDP in most countries (Davila Delgado et al., 2019). Despite its huge economic importance, the construction industry is traditionally slow to change and consequently beset with inefficiencies resulting in lower productivity levels compared to other sectors (Davila Delgado et al., 2019). However, despite the complexity and fragmentation of the construction industry and the difficulties of coordinating the wide numbers of players and their tasks that slow down the introduction of innovative solutions, the construction sector has evolved in the last 25 years. This is especially driven by digital technologies and automation providing the construction industry with an opportunity to find innovative solutions to some of its rooted challenges. These innovations spanned across the whole project lifecycle, from design and engineering, through manufacturing and construction, to operation and maintenance, and retrofit/reuse/end-of-life. Among these, robotics is an emerging technological branch that can have an impact in construction areas such as off-site production, installation activities on-site, and operation and maintenance. This chapter will provide key insights about the digital transformation enabled by IER solutions in construction sites, analyze their current applications, limitations, and future developments, and propose an assessment framework to support construction actors in the decision-making process into the gradual adoption of IER for performing specific tasks.

Fig. 8.1
A snapshot of a glass-encased structure. Two support beams are propped up on the building, and four workers are cleaning the facade.

Allianz Tower while human workers are cleaning the façade. (Credit: Piermario Ruggeri-Focchi façade)

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8.3 Advantages and Benefits of IER

8.3.1 Improving Safety

The incident rate in the construction industry is the highest among various major industries in many countries (Choi et al., 2011). In the US, 25% of the fatal work injuries in 2020 belong to the construction sector (U.S. Bureau of Labor, 2021). In Great Britain, 1.8% of the construction workers reported a musculoskeletal disorder, which is the highest rate among the industries with similar work activities (Health and Safety Executive, 2021). Replacing humans by semi-autonomous and autonomous robots for undertaking unsafe tasks can reduce the number of incidents (Ilyas et al., 2021). Robots can be used for automating unsafe activities including heavy lifting and on-site inspection in dangerous work environments such as underground mines (Zimroz et al., 2019) and bridges (Lin et al., 2021). To reduce musculoskeletal injuries and physical fatigue of construction workers caused by repetitive and prolonged manual tasks, exoskeleton is being used for augmenting workers’ physical ability (Brissi et al., 2022). Safety inspections and monitoring are other tasks that can be automated by robots for detecting unsafe locations (Martinez et al., 2020) and Personal Protective Equipment (PPE) on job sites (Ilyas et al., 2021).

8.3.2 Improving Productivity

Productivity growth has been a major concern in the construction industry as it was only one-third of the average total economy productivity growth over the past 20 years (Ribeirinho et al., 2020). Productivity of the construction industry can be improved by automating and robotising repetitive and labour-intensive activities. Autonomous transportation of construction materials by robots can improve productivity and eliminate human errors in these processes (Chea et al., 2020). For heavy lifting, robotic crane systems could improve productivity by 9.9–50% (Lee et al., 2009). The examples of IER applications for automation of different construction activity types are presented in Table 8.2.

Table 8.2 IER application for improving productivity of different types of construction activities
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8.3.3 Addressing Skilled Worker Shortage

Skilled worker shortage has been one of main issues in the construction industry over the past few years (Kim et al., 2020). The growing demand of construction workers and the aging workforces in many countries such as the UK (CITB, 2021; Green, 2021) are the main contributors to the skilled worker shortage. In the long term, leveraging construction automation and replacing humans with IER can address this issue (Melenbrink et al., 2020). In addition, use of IER can address the challenges of the high labour wage in construction projects particularly in the metropolitan areas (Pan et al., 2020).

8.4 Key Use Cases for Intelligent Construction Equipment and Robotics

Although the impact of IER has not yet been fully realised in the construction industry (Carra et al., 2018), their applications are emerging to enhance construction productivity, safety management, quality control, and site planning issues. The first examples of construction robots were seen in the Japanese construction industry in the late 1970s and 1980s to supplement and replace workforce (Yilmaz & Metin, 2020). Construction automation and robotics application are classified in this chapter according to:

  • Construction phase involvement—whether they are applied at the construction site (related to on-site activities) or at a factory for prefabrication activities (related to off-site activities) (Saidi et al., 2016). (Table 8.3);

  • Level of autonomy—the second classification is based on the level of autonomy that IER technologies allow to perform (Table 8.4).

Table 8.3 Description of construction phase for IER classification
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Table 8.4 Description of autonomy level for IER classification
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IER technologies can be further classified based on their technology readiness level (TRL) which identifies the maturity of the technologies within the market. In particular:

  • TRL < 5—implies technologies which have been prototyped;

  • TRL 6–7—implies technologies which have been tested and validated in an operational environment;

  • TRL > 8—implies technologies which are widely used on market, indeed are considered actual system/process completed, and qualified through test and demonstration (pre-commercial demonstration).

Table 8.5 shows TRL for different IER technologies. The TRL level has been assigned based on market and academic research.

Table 8.5 TRL of the available IER technologies (TRL <5 listed as “✓,” TRL 6–7 listed as “✓✓,” TRL > 8 listed as “✓✓✓”)
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The next subsections present some key examples of IER applications in the construction industry to highlight their significant impacts on various aspects of construction projects.

Additive manufacturing for construction phase—MX3D Bridge is a pedestrian bridge designed with generative design—complying between sustainable aspects and structural needs—and manufactured by exploiting the synergies between robotic and additive manufacturing. This is one of the first impactful examples for metal components moving from intelligent design to robotic-based production, validating the notion of the ability of such systems to move the construction sector into industrialised construction (MX3D Bridge, 2020) (Figs. 8.2 and 8.3).

Fig. 8.2
A photograph of a M X 3 D bridge with two thick yet curvy railings while the bottom is a pattern of thick and thin curvy lines. A person walks on the bridge while another walks adjacent to it.

MX3D Bridge. (Photo by Joris Laarman Lab)

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Fig. 8.3
A snapshot of a M X 3 D bridge with two thick and curving sides that form an intricately designed 3-dimensional pattern. Various people are crossing this bridge, while some stand by as observers.

MX3D Bridge. (Photo by Adriaan de Groot)

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Automatics monitoring for inspection—The potential of the combination between digital platform and inspection robotics is providing new opportunities for construction. This is well represented by the collaboration of Boston Dynamics and its sophisticated and movable robots SPOTWALK with HOLO BUILDER platform for the site project management controls which is revealing new digital workflows in the construction sector (HoloBuilder and Boston Dynamics Launch SpotWalk for Autonomous Reality Capture | Geo Week News | Lidar, 3D, and More Tools at the Intersection of Geospatial Technology and the Built World, 2020) (Figs. 8.4 and 8.5).

Fig. 8.4
A photo of a robot with forelegs and hind legs. The center section serves as a support for other machines put on top. It features the letters B 0 4 on the side.

Spot robot for autonomous 360° photo capture. (Image courtesy of HoloBuilder)

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Fig. 8.5
A photo of a foreleg and hindleg robot. The center section is used to support other gear that is placed on it. It features the words B 0 4 on the side. A person controls the robot via a smartphone app.

HoloBuilder SpotWalk integration with Boston Dynamics. (Image courtesy of HoloBuilder)

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Unmanned Aerial Vehicle (UAV) for maintenance activities—UAVs could reach hazardous or high places, which is becoming a diffused practice with heightened expectations considering the opportunities that these technologies open to control the health of built assets. For instance, Elios is a UAV tool which inspects the photovoltaic (PV) panels with the aim of tracking and monitoring each cell to discover irregularities or loss of performances (Elios Aerial Thermography, 2021) (Figs. 8.6 and 8.7).

Fig. 8.6
A photo of a drone flying through the sky. Multiple solar panels are laid out on the ground and tiled toward sunlight.

Thermography inspection of a PV plant by drone

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Fig. 8.7
A user interface for mobile applications Elios displays the solar panels and their configuration, highlighting the panels with flaws.

Wesii digital platform: RGB view with colored anomaly classification

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Robotics arm in construction phase—MULE is a construction robot, flexible, portable, job-site ready lift assist which reduces time for lifting activities by 80% (MULE Lifting System | R.I. Lampus, 2021). ROB-Keller System AG have designed Robotic brickwork, Rob, to control the positioning of the masonry entirely positioned and controlled by the robotic arm. Rob allows to build walls even with shapes in compliance with the calculations and resistance simulations made in the design phase (Robotic Brickwork, 2021).

Vehicles for construction phase—HX2 is an autonomous and electric load carrier that can move heavy construction components. It has a vision system that allows the robot to detect humans and obstacles (Volvo CE Unveils the next Generation of Its Electric Load Carrier Concept, 2020).

Exoskeleton—Eksovest is an upper-body exoskeleton that supports arms during lifting activities (Exoskeletons Trialled on UK Construction Sites, 2021). Exopush, developed by Colas, is an exoskeleton designed to give power assistance to operatives working leveling with a rake. The exoskeleton improves the worker posture by reducing the stress movement of 30% (Colas Introduces the Exopush Exoskeleton to the UK, 2021). G-Ekso bionics has developed a robot which is able to hold heavy tools on aerial work platforms like scissor lifts and to standard scaffolding (EksoZeroG—Zero Gravity Tool Assistance, 2021).

Integrated solution—Hephaestus—A H2020 co-funded project has designed an IER tool for the installation of prefabricated building envelopes (Elia et al., 2018; Highly AutomatEd PHysical Achievements and PerformancES Using Cable RoboTs Unique Systems | HEPHAESTUS Project | Fact Sheet | H2020 | CORDIS | European Commission, 2020). The Hephaestus robot is composed of a cable-driven parallel robot (CDPR) and a modular End-Effector kit (MEE) which host tools and devices for the bracket positioning and façade modules installation. This robot expects in the next few years to provide a market autonomous solution for on-site tasks for installation of prefabricated envelopes, focusing on highly risky and critical construction tasks. The long-term purpose is to adopt Hephaestus not only for the installation stage but also for operations of maintenance and façade module replacement (Figs. 8.8 and 8.9).

Fig. 8.8
A photograph of a structure linked to a demonstration building. It has a cable connected to a pulley at the top and a rectangular construction on the other sides.

Cable-driven parallel robot installed in the demo building. (Credit Alex Iturralde)

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Fig. 8.9
A photograph of the parts of the facade mechanism.

Hephaestus details during façade installation. (Credit Alex Iturralde)

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8.5 IER for the Renovation Phase

In Europe more than 70% of the building stock was built before the 1970s and suffers from poor energy performance. Renovation is a key strategy to reduce the energy impact and the carbon footprint of buildings. The European Commission’s target is to retrofit at least 3% of the building stock market by 2030. The retrofitting intervention involves changing in the building configuration to improve the energy performance while maintaining the occupant’s comfort (Green Building 101, 2014). In this scenario construction automation and robotics can accelerate retrofitting interventions. For example, robotics applications support the existing workforce with on-site activities, which are currently based on crafts-oriented processes (Tellado, 2019). However, current key advantages of using robotics in retrofitting projects are focused on building data collection especially for the planning and design phase such as:

  • Data collection regarding current building dimensions and shapes (survey). The utilisation of robotics as UAVs allows to collect accurate data in a reduced amount of time.

  • Data collection regarding current building energy consumption by analyzing current building energy data, identifying areas with energy wastages, and understanding building energy use.

Robotics applications play a crucial role in addressing the challenges of building energy retrofit (Mantha et al., 2018). Accurate measurements, real time, and instant transfer of data can be integrated in the Building Information Modeling (BIM)Footnote 1 and exploited by relevant IER operations. A generic framework could be developed to support the data collected to arrive at an optimal building retrofit decision (e.g., most economical and most energy saving). Some examples are Bertim (Refurbishment Solutions | STUNNING), which is a H2020 project that aimed to enhance a building retrofitting intervention by integrating automation applications in the process, and Vertliner (VERTLINER)—an application-focused autonomous UAV that navigates inside the building, acquiring precise 3D data, images, or videos—to inform and update several layers of digital twin models and BIM representing the indoor environment.

8.6 Challenges and Barriers

Despite the advantages and benefits of IER, the construction industry has faced several challenges and barriers with their adoption as summarised in Table 8.6.

Table 8.6 Challenges for adopting IER in the construction industry
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8.7 Frameworks for Assessing and Implementing IER

A systematic approach to guide IER implementation is still missing in the construction sector (Hu et al., 2021; Pan et al., 2018). This section proposes a preliminary framework of indicators for assessing the advantages of using IER for buildings based on the current construction needs. The framework is designed for construction companies interested in evaluating whether robotic applications facilitate their planned tasks according to specific tasks’ indicators. Using the selected metrics, the framework compares between the current manually handled tasks with the ones achievable by the adoption of a selected robotic technology. Hence, a quantitative ranking is used for the different tasks assigning a score for key macro indicators (quality, safety, time and cost) with the following scores:

  • “−2” The robotic adoption hugely worsens task’s indicators

  • “−1” The robotic adoption worsens task’s indicators

  • “0” The robotic adoption does not affect task’s indicators

  • “+1” The robotic adoption improves task’s indicators

  • “+2” The robotic adoption hugely improves task’s indicators

The total of all scores is a preliminary result to evaluate the IER for the selected activity: if the total score is positive, IER could facilitate the construction work, and if the total score is negative, IER will not improve the construction work.

The assessment framework is a preliminary decision support tool to facilitate the evaluation about advantages for IER adoption. More detailed investigation will need to be implemented to boost IER technologies adoption, especially once more solutions are available on the market. At this stage, the proposed framework can be considered an early-stage tool for navigating the advantages of emerging IER applications in the construction industry (Table 8.7).

Table 8.7 Framework of indicators for assessing the advantages of using IER for buildings
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8.8 Conclusion

There is emerging evidence that IER can benefit on-site and off-site construction operations. However, there are some challenges and barriers to overcome. From a contractor-side, economic factors including the high capital costs along with the costs pertaining to training and upskilling workers to operate IER are the main challenges. The nature of construction sites, which is generally unstructured, complex, and dynamic, entails further safety and operational challenges for using IER. Moreover, inadequate digitalisation levels within the construction industry limit the utilisation of IER. Tools for comparing traditional methods with advanced IER technologies are lacking in the construction industry. To contribute to these important gaps, this chapter classified the application of IER, reviewed key emerging applications and technologies, and proposed a framework to help assess the feasibility of implementing IER in construction. While some challenges to the adoption of IER are likely to persist in the short and mid-term, the emerging opportunities opened by IER have started to offer evidence about their disruptive nature and positive impact to quality, safety, and productivity in this key industry.