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Off-site construction (OSC) has been regarded as a clean and efficient production approach to help the construction industry towards sustainability. Different levels of OSC technologies vary greatly in their implementations and adoptions. Compared to low OSC level technologies have been applied widely, the adoption of high OSC level technologies (HOSCLTs) in practice remains limited. The adoption mechanism for HOSCLTs by firms has not been clear, hindering their promotion. This study aims to explore the mechanism combining subjective and objective adoption for HOSCLTs.

This study developed an integrated model illustrating mechanism for HOSCLTs adoption based on the technology acceptance model (TAM), which has strong capacity to explain potential adopters' subjective intentions to adoption, and the task-technology fit (TTF) theory, which well describes the linkages between the task, technology and performance in technology adoption. The proposed model was then empirically evaluated through a survey of 232 practitioners in the Chinese OSC industry using partial least squares structural equation modeling.

The results indicate that both task characteristics (TAC) and technology characteristics (TEC) positively affect TTF of HOSCLTs. TAC, TTF, firm conditions and stakeholder influence have significant positive effects on perceived usefulness (PU), which further positively influence attitude towards adoption. TEC and firm conditions are significantly related to perceived ease of use (PEU). TTF, PEU and attitude towards adoption are good predictors of behavior intention to HOSCLTs adoption. PEU only significantly influences adoption intention and is not observed to influence attitudes and PU, unlike prior research on common OSC adoption.

This study contributes to the body of knowledge by exploring HOSCLTs adoption in the industry based on distinguishing the levels of OSC technologies and supplementing an integrated model for explaining the mechanism with the combination of subjective and objective adoption. The study also provides useful insights into understanding and promoting HOSCLTs adoption for policy makers and stakeholders actively involved in the OSC field.

Although prefabricated construction (PC) technology has attracted considerable attention worldwide because of its significant role in the global fight against COVID-19, market-driven adoption is still limited. The mechanisms for PC technology adoption have yet to be defined, which inhibits its diffusion in the construction market. This study aims to reveal the intrinsic motivation and action mechanism for PC technology adoption.

Drawing on the technology acceptance model (TAM), the study integrates characteristics from the diffusion of innovation theory to propose a multifaceted model for explaining practitioners’ PC technology adoption behavior from technology, organization and environment contexts. The proposed theoretical model was empirically examined via a survey of 234 professionals in mainland China using the partial least squares-structural equation modeling technique.

The outcomes indicated that relative advantage, corporate social responsibility and market demand are significantly positively related to practitioners’ perceived usefulness from PC technology. Regulatory support and trading partner support have noticeable positive effects on practitioners’ perceived ease of use from PC technology. Perceived ease of use is found to positively influence perceived usefulness, and both of them have a positive influence on the attitude toward adopting PC technology. Attitude is further confirmed as an important predictor of adoption intention, which would lead to actual PC technology adoption behavior.

To the best of the authors’ knowledge, this paper is the first attempt to explore industry perceptions toward PC technology adoption, providing valuable guidance for the effective diffusion of PC technology and laying a reliable foundation for research on other construction innovation adoption in post-COVID-19.

The coordinated development of the urbanization and construction industry is crucial for the sustainable development of cities. However, the coupling relationship and coordination mechanism between them remain unclear. To bridge this gap, this study attempts to explore the level of coupling coordination between new urbanization and construction industry development and investigate the critical driving factors influencing their coupling coordination degree.

By referring to the existing literature, two index systems were established to evaluate the development level of the new urbanization and construction industry. The spatiotemporal characteristics of the coupled coordinated development of the new urbanization and construction industry in China from 2014 to 2020 were investigated using the coupling coordination model. The Markov chain and geographic detector were adopted to understand the transition probability and driving factors of the coupling coordination degree.

The results indicate that the coupling degree of China's new urbanization and construction industry is high, and the two systems exhibit obvious interaction phenomena. However, the construction industry in most provinces lags behind the new urbanization. A positive interactive relationship and coordination mechanism has not been established between the two systems. Furthermore, the  coupling contribution degree of the driving factors from high to low is as follows: market size > labor resource concentration > government investment ability > economic development level > industrial structure > production efficiency > technology level. Accordingly, a driving mechanism including market, policy, economic, and production technology drivers was developed.

This study contributes to the existing body of knowledge by providing a set of scientific analysis methods to address the deficiency of coordination mechanism research on new urbanization and the construction industry. The results also provide a theoretical basis for decision makers to develop differentiated sustainable development policies.

Stab-resistant body armor (SRBA) can protect the human body from injury as a result of stabbing by sharp projectiles. However, in its current design SRBA, it has not been widely adopted for use, because of its weight and poor flexibility. Herein, this paper aims to detail a new type of SRBA that is inspired by the armor plating of mammals and is fabricated using laser sintering (LS) technology.

This new type of SRBA was fabricated using LS technology. The laser sintered SRBA was subjected to a stab resistance performance test that conformed to the GA 68-2008 Chinese National Standard. The stab resistance response of the novel structured, stab resistance test plates in this study was analyzed using the using the AUTODYN explicit module in ANSYS-Workbench.

The structure of the novel stab resistance plate was designed and the optimum structural parameters were tested, discussed and achieved. The mechanism of dissipation of the impact energy by the pyramidal structures of the novel SRBA was studied, and it was found that this structure dispersed the kinetic energy of the knife and minimized the structural damage to the plate. Interlinks inspired by the pangolin hierarchy structure were designed and used to fabricate a large piece of laser sintered body armor.

High-performance laser sintered stab resistance plate was produced via the material and structure studies, which could reduce 40 per cent weight on the stab resistance body armor and increase the wearability.

Contractor selection is critical in green buildings (GBs) since the preferred contractor has the responsibility to achieve construction sustainability as well as relationship sustainability. The developer satisfaction reflecting requirements can boost the cooperative relationship among stakeholders and act as an evaluation scale for the success of GB projects, which needs to be emphasized in the selection process but little involved in the existing research. This study explores improving GB contractor (GBC) selection by integrating developer satisfaction into selection procedures.

A systematic framework of GBC selection including twenty-five criteria from literature review and experts survey is firstly constructed. Both tactical and strategic criteria are further classified into Kano categories (must-be, one-dimensional, and attractive categories) using the fuzzy Kano model (FKM), and weighted by the developer satisfaction index. The model proposed by this study combining FKM and TOPSIS divides the selection process into the filtration phase and selection phase by Kano categories. The proposed model is finally verified through performance comparison among multiple methods in a case.

Selection criteria are measured linearly and nonlinearly, showing criteria having nonlinear satisfaction change accounts for two-thirds of all. Criteria at tactical level tend to be must-be or one-dimensional categories for the developer, and most strategic criteria are classed as the attractive category, indicating that adding strategic criteria is necessary for long-term cooperation. The proposed model, using developer satisfaction to improve the selection process, ensures the selected GBC to be the most satisfactory with requirements of the developer and makes the performance of GBCs easily distinguishable.

This study contributes to the existing body of knowledge for promoting relationship sustainability by supplementing an integrated model with emphasis on developer satisfaction in GBC selection, so as to establish a good initial foundation due to the match between performances of GBCs and needs of developers. It not only helps maximize developer satisfaction in GBC selection by applying satisfaction to pre-construction management, but also instructs GBCs to prioritize performance improvements. The framework is also conducive for developers to classify selection criteria and select other participants (like green suppliers) from the satisfaction perspective in GBs.

The purpose of this paper is to present a new technique for monitoring gas leakage in underground pipelines to prevent dangerous explosions.

A novel system for monitoring methane concentration in underground spaces was developed by integrating the multi-channeled air sampling method with an infrared gas sensor. A pipe installation methodology (without excavation) was established and verified accordingly.

The proposed approach was proven successful in reducing the quantity of sensors needed for real-time monitoring of underground pipeline leakage by about 80 per cent. Furthermore, this system lowers total operational cost by as much as 60 per cent.

The results presented here represent a possible solution to reducing the public safety risks associated with explosions and fires caused by pipeline leakage in underground spaces. Its total cost is low and its monitoring efficiency is high.

The purpose of this paper is to improve the quality of additive manufactured optically translucent parts by investigating the manufacturing issues, analyzing lithophane production criteria and identifying the best translucent material and additive manufacturing (AM) technology.

Figured lithophanes were laser sintered on a 3D Systems SinterStation® HiQ™ with varying layer thickness and plate thickness. Laser sintered (LS) polyamide (PA) 12 blanks were cyanoacrylate infiltrated and polished. Optical properties and performance were compared with the original LS blanks. Lithophanes and blanks were manufactured using 3D systems stereo lithography apparatus (SLA)® Viper ™si2 station, and optical properties and lithophane performance were compared with the LS specimens.

When building in the XY plane, it is optimal to sinter with the minimum layer thickness (0.076 mm) and maximum plate thickness (5 mm). Cyanoacrylate infiltration and polishing assists in reducing the LS PA 12 plate surface roughness, but polishing does not affect the lithophane performance. The best LS candidate should have an absorption coefficient of 0.5/mm using a white light source. Improved resolution but reduced contrast was observed on stereolithography (SL) specimens compared to LS parts.

Transmittance experiments were performed on three SL parts which was not sufficient for optical property calculation. Limited literature was found for new material exploration.

It is the first effort to study systematically quality improvement issues of LS PA optically translucent parts. A comparison is made of optical performance between parts made using LS and SL.

This paper aims to analyze the additive manufacturing orientation effect of laser sintered polyamide 12 (PA 12) optically translucent parts.

Plates with small features, wedges and lithophanes were laser sintered on a SinterStation HiQ™ in different orientations using PA 12. Lithophane performance was assessed using a Picker 240050 X-ray view/light box. All parts were examined using stereomicroscopy to capture the small features.

The quality of the lithophane image was substantially improved by orienting the flat plate side to the incident backlit light. Sintering in the ZX/ZY plane significantly increased the contrast and resolution compared to sintering in the XY plane. The thinnest feature thickness possible in the SinterStation HiQ is in the XY plane 0.13 mm, and it is 0.57 mm when manufacturing in the ZX/ZY plane.

The laser spot size and other machine parameters were not changeable, which limited the manufacturing resolution. Oblique, non-orthogonal orientations were not investigated.

This is a first effort to investigate the manufacturing orientation effect of laser sintered polyamide optically translucent parts. The manufacturing resolutions on different planes were defined.

The purpose of this paper is to report selected optical properties of laser sintered polyamide 12 blank plates under different monochromatic and white light conditions and to apply these properties in production of laser sintered lithophanes.

A UNICO 1201E spectrophotometer was used to measure the transmittance of laser sintered polyamide 12 plates as a function of plate thickness. Monochromatic light-emitting diodes were used to assess the wavelength dependence on the transmission and contrast as captured by a SONY DSC-W55 camera.

The transmittance decreased with increasing plate thickness which varied significantly depending on the monochromatic wavelength. Highest transmission was observed using green light (525 nm) and poorest transmission was measured for yellow light (589 nm).

There is a limit to the amount of contrast obtained in polyamide lithophanes because the thickness of the plates is limited to less than about 5 mm. Greater thickness results in discernible topology on the lithophane which impairs the quality of the image.

Light transmittance of polyamide 12 plates under different lighting conditions is reported and applied to optically defined laser sintered lithophanes.

The purpose of this paper is to acquire thermal conductivities of both fresh and preheated polyamide 12 powder under various conditions to provide a basis for effective and accurate control during the laser sintering (LS) process.

A Hot Disk® TPS 500 thermal measurement system using a transient plane source (TPS) technology was employed for thermal conductivity measurements. Polyamide 12 powder was packed at different densities, and different carrier gases were used. Tests were also performed on fully dense laser sintered polyamide 12 to establish a baseline.

Polyamide 12 powder thermal conductivity varies with packing density and temperature, which is approximately one-third bulk form thermal conductivity. Inter-particle bonding is the primary factor influencing polyamide 12 thermal conductivity.

Limited ranges of density were tested, and the carrier gas needed carefully control to prevent powder oxidation. Thermal properties obtained were not tested in the LS process.

This experimental result could be used to enhance thermal control during the LS process.