In this research, a low-damage seismic design technology has been proposed for accelerated bridge construction (ABC). ABC low damage aims to minimize, and potentially eliminate, damage in a precast bridge during an earthquake. The low-damage design uses dissipative controlled rocking (DCR) connections between the precast elements in a bridge substructure. A DCR connection replaces the traditional plastic hinge at the column-to-footing or column-to-cap beam locations. DCR combines unbonded post-tensioning and externally attached metallic dissipaters to provide self-centering and energy absorption capabilities for the bridge, respectively. In this research, a half-scale precast bent was tested under quasi-static cyclic loading to validate the concept of low-damage design. The performance of the bent was compared against an equivalent bent with emulative cast-in-place connections. Results from testing suggested high performance of the low-damage bent. Following many cycles of large drift ratios, there was no damage or residual displacement in the bent. Findings from this research were implemented in the Wigram-Magdala Link Bridge in Christchurch, New Zealand, in July 2016. The bridge remained intact during the Kaikoura Earthquake on November 14, 2016.

Hydrogen is a notoriously difficult substance to store yet has endless energy applications. Thus, the study of long-term hydrogen storage, and high-pressure bulk hydrogen storage have been the subject of much research in the last several years. To create a research path forward, it is important to know what research has already been done, and what is already known about hydrogen storage. In this review, several approaches to hydrogen storage are addressed, including high-pressure storage, cryogenic liquid hydrogen storage, and metal hydride absorption. Challenges and advantages are offered based on reported research findings. Since the project looks closely at advanced manufacturing, techniques for the same are outlined as well. There are seven main categories into which most rapid prototyping styles fall. Each is briefly explained and illustrated as well as some generally accepted advantages and drawbacks to each style. An overview of hydrogen adsorption on metal hydrides, carbon fibers, and carbon nanotubes are presented. The hydrogen storage capacities of these materials are discussed as well as the differing conditions in which the adsorption was performed under. Concepts regarding storage shape and materials accompanied by smaller-scale advanced manufacturing options for hydrogen storage are also presented.

Although New Zealand bridges performed well structurally during recent Canterbury earthquakes, some critical arterial routes lost their functionality. Life Safety is still our primary objective but nowadays we are moving towards new societal needs which also, at minimum, aim to limit business disruption. Building designers are already moving towards low-damage system technology for both structural and non-structural components. Bridge engineers have to inherit those enhanced concepts and technologies. In fact, in order to protect the economy and save lives, it is vital that bridges remain drivable after a natural disaster, such as an earthquake. More importantly asset managers and networks’ owners want rapid response, design flexibility, quick construction and limited maintenance costs. This should be possible to be achieved by contractors and designers with limited budgets. In very populated urban centres or a critical network location and moderate-to-high seismicity an Accelerated Bridge Construction (ABC) technology which combines durable materials and low-damage technology, seems to be the only viable solution to minimize traffic disruption during the bridge life. The American Association of State Highway Transportation Officials (AASHTO) started in 2002 a long-term strategic bridge plan which aims to cover all these issues. Similar research strategy was initiated in Japan, Taiwan and Europe which is slowly going towards adaptation of ABC as a standard bridge practice. The question would be what is New Zealand vision for the next twenty-thirty years? This paper aims to overview the current international trends and challenges and gives innovative concepts which can be contextualized for New Zealand bridges.

The purpose of this study is to utilize waste products—precipitated calcium carbonate (PCC) and upcycled recycled concrete aggregate (upcycled RCA or UCA)—in civil works projects. To do so, tests must be performed to determine the engineering properties of the materials in which PCC and UCA are sequestered. PCC is a fine to coarse grain waste product generated during the production of sugar from sugar beets. UCA is produced from demolished and returned concrete by the extraction of primarily calcium and alkalinity. The study also includes the use of both PCC and UCA in the same concrete mix design. The test results on PCC alone show that the optimum content to achieve a minimum 28 MPa (4000 psi) compressive strength is 25% and 30%. The corresponding compressive strength of mixes in which conventional aggregate was replaced by UCA is about 48 MPa (7000 psi) to 55 MPa (8000 psi) at the same water: cement ratio (0.44) by weight. The compressive strength of concrete with 25% to 30% cement replaced by PCC and varying aggregates replaced with UCA ranges from 19.3 to 40 MPa (2800 to 5800 psi). Other tests on PCC and UCA include tensile strength of 2 to 3 MPa (293 to 423 psi) and flexural strength of 1.3 to 1.9 MPa (183 to 279 psi). Analytical techniques such as X-ray diffraction (XRD), energy-dispersive X-ray spectrometry (EDX), and scanning electron microscopy (SEM) were used to identify the constituent elements and chemical compounds present in PCC, including calcium carbonate and silica. Based on the test results, the composition of PCC by weight indicates 45.9% calcium, 39.4% oxygen, and 9.2% carbon. Based on the results of this study, we can expect to reduce carbon emissions in the production of cement and aggregates, as well as utilize waste products in the civil engineering field.

This review paper addresses the escalating operation and maintenance costs of nuclear power plants, primarily attributed to rising labor costs and intensified competition from renewable energy sources. The paper proposes a paradigm shift towards a technology-centric approach, leveraging mobile and automated robots for physical security, aiming to replace labor-intensive methods. Focusing on the human–robot interaction principle, the review conducts a state-of-the-art analysis of dog robots’ potential in infrastructure security and remote inspection within human–robot shared environments. Additionally, this paper surveys research on the capabilities of mobile robots, exploring their applications in various industries, including disaster response, exploration, surveillance, and environmental conservation. This study emphasizes the crucial role of autonomous mobility and manipulation in robots for diverse tasks, and discusses the formalization of problems, performance assessment criteria, and operational capabilities. It provides a comprehensive comparison of three prominent robotic platforms (SPOT, Ghost Robotics, and ANYmal Robotics) across various parameters, shedding light on their suitability for different applications. This review culminates in a research roadmap, delineating experiments and parameters for assessing dog robots’ performance in safeguarding nuclear power plants, offering a structured approach for future research endeavors.

Accelerated bridge construction (ABC) technologies are being adopted by state departments of transportation. ABC requires that bridge precast concrete components be effectively connected to one another in the field. Currently there is a trend of using ultra-high performance concrete (UHPC) to connect precast bridge deck panels or girders in 15-cm (6-in.)-wide closure pours between the precast elements. As an alternative, the Idaho Transportation Department (ITD) is proposing to place high-early strength (HES) concrete with polypropylene fibers in 25-cm (10-in.) closure pours, with standard reinforcing bars at the top and headed bars at the bottom. The advantages of this alternative material are the reduction in costs and construction time. An experimental research project was carried out to determine the effectiveness of the alternative material and connection detail. The experimental work consisted of standard test specimens and specimens with headed bars. Among the six closure pour concrete mixes considered, the mix containing HES concrete, $0.89\mathrm{kg}/{\mathrm{m}}^3$ ($1.5\mathrm{lb}/{\mathrm{yd}}^3$ ) of fiber, and shrinkage-reducing admixture performed the best. It had the largest compressive strength, the largest tensile strength, the lowest shrinkage, and the largest bond strength. Headed bar tensile strength tests with the optimum mix resulted in bar stress of 67% of the steel specified yield strength. Flexural testing of beams composed of two precast segments with the optimum mix in the 25-cm (10-in.) closure resulted in ultimate moment capacity of about $55\mathrm{kN}·\mathrm{m}/\mathrm{m}$ ($147\mathrm{kip}\text{-}\mathrm{in.}/\mathrm{ft}$ ).