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This briefing provides a short introduction to a supplement of the Ciria Manual on Scour at Bridges and Other Hydraulic Structures published in 2021. The supplement captures additional knowledge since the scour manual was published in 2015. This note is intended for designers and asset managers of structures in the water environment that may be subject to scour.

Soils containing organic matter exhibit low shear strength and high compressibility. Lime stabilisation has been shown to improve the engineering properties of clayey soils. An attempt was made to study the effect of organic matter (starch and peat) on the shear strength of lime-stabilised clayey soils subjected to longer curing periods (up to 180 days). Most studies have reported the strength behaviour of lime-stabilised organic soils up to 60 days. Vane shear tests were carried out on artificially prepared organic soil mixtures treated with 6% lime after different curing periods (0, 7, 30, 60, 90 and 180 days). The results indicate that the improving effect of lime is deteriorated in the presence of organic matter as the curing period increases. It was observed that, for lime-stabilised clayey soils containing organic matter, the strength seemed to increase up to 30 days, after which it ceased. The strength reduction in lime-stabilised clayey soils containing organic matter depended on the pH and functional groups present in the soil. Fourier transform infrared spectroscopy of cured samples was also carried out to examine the microstructural changes responsible for the strength change in lime-stabilised clayey soils.

This study analyses the effectiveness of the biopolymer xanthan gum (XG) to improve the mechanical properties of silty sand. The study focuses on the effects of the curing time and the content of XG on the unconfined and confined behaviour of soil treated with this biopolymer. The study was carried out with specimens cured under high-humidity conditions, through the comparison of the unconfined compressive strength (UCS), stiffness, compressibility and vertical yield stress of non-stabilised and biostabilised specimens, obtained from UCS and oedometer tests. Additionally, the pH value and results of scanning electron microscopy (SEM)/ energy-dispersive X-ray analysis (EDX) tests are presented and discussed. The biostabilisation of this soil with XG induces a more ductile stress–strain behaviour, a moderate increase in UCS and stiffness, and in the increase of the one-dimensional compressibility, with a greater effect for higher XG contents. The SEM/EDX tests show that the biopolymer induces a random biopolymer network in the biostabilised specimens that is related to the strengthening obtained.

The Wan Jiang Bridge in China was damaged by ship impact and subsequently restored. This paper presents a detailed evaluation of the residual service life (RSL) of the bridge using the reliability analysis method of the Joint Committee on Structural Safety, based on the structural load-bearing capacity (LBC) of the bridge and the design load. Data were collected from bridge design codes, field loading tests and finite-element (FE) analysis. The LBC was initially calculated and subsequently revised using specific coefficients. Using FE analysis, the bending moment on the control section of the bridge was determined under the most unfavourable loading conditions and the ultimate LBC of the bridge was checked. Subsequently, static and dynamic loading tests on the restored bridge were conducted, with the load and capacity determined for the control section based on FE analysis. The loads considered were dead load, vehicle load and crowd load. A time-dependent reliability index was developed for the restored bridge using the probability distributions of capacity and design load variables, and the RSL was determined. This case study, predicting the RSL of the bridge based on a multitude of data, should be valuable for future bridge maintenance and management.

Environmentally friendly materials are being explored as alternatives to lime and cement binders in ground improvement. Biological treatment methods are environmentally friendly as they rely on the natural activity of ubiquitous microbes to produce extracellular polymeric saccharides (EPS) and calcite cements. EPS extruded by microbes exhibit strong adhesion from growth of fibrous bridges and bonds between surfaces. In situ polysaccharide secretion in soils to improve their engineering properties has not been examined. In this study, pulverised dried cattle manure (CM) are is used for in situ EPS production in a synthetic soft soil specimen. The indigenous facultative anaerobes and aerobes in animal waste produce negatively charged EPS molecules in the soil specimen. Bridging of sand particles and embedment of CM fibres in kaolinite aggregates caused an immediate increase in unconfined compressive strength (UCS) of the stabilised specimen. EPS cementation improved soil strength by filling pores and engulfing kaolinite aggregates into bonded mass. Fibre reinforcement and bio-stabilisation by CM increased the UCS of the soil by 740%. Replacing C-intensive lime/cement binders by CM as a stabilising agent has the potential to prevent release of 1 t of carbon dioxide to the atmosphere per tonne of lime/cement consumed.

In recent years, the aging of existing reinforced concrete deck slabs of road bridges in Japan has been attributed to the deterioration of the concrete on the upper surface, and partial replacements have been carried out as a measure to extend service life. This study comparatively verifies the effectiveness of the partial cross-section replacement method, using a wheel load running test and focusing on the combination of the removal method of the existing concrete and the repair material. An appropriate method of partial replacement of existing reinforced concrete deck slabs is also proposed.

This paper contains a summary of the experience obtained by researchers at the Instituto Universitario de Ciencia y Tecnología del Hormigón (ICITECH) at Universitat Politècnica de València (Spain), in the last 30 years of investigating reinforced concrete building structures under construction. During this period, ambitious experimental campaigns and advanced computational simulations have been carried out, and new analytical methods have been formulated to assess slab–falsework load transmissions in buildings under construction. From all these campaigns the following main conclusions can be derived. First, it is important to consider construction processes when planning building projects. Second, the use of analytical methods to evaluate construction processes need to be adapted to the current requirements of efficiency and sustainability. Third, there is a need to improve the robustness of temporary shoring or propping structures. Improving the construction sector necessarily involves the implementation of the above measures in buildings under construction and the use of new monitoring and inspection technologies for the construction processes applied.

To understand the influence of the layout and geometric parameters of the lining concrete on the mechanical properties of multi-cell single-box girder bridges with corrugated steel webs, the Fenghua River Bridge is taken as an example. This is a single-box three-cell continuous girder bridge with corrugated steel webs that is the largest of its kind in China. It was used to establish the finite-element model in this paper. The results of this study suggest that the lining concrete single-side arrangement has good economic and mechanical properties. The influence of the geometric parameters of the lining concrete on the mechanical properties of the structure was studied using the finite-element model, and the length and thickness range of the lining concrete of the single-box multi-cell composite girder bridge with corrugated steel webs are provided. The research results provide useful suggestions for the design of lining concrete in real bridge projects, and thereby make up the gap in the existing code.

Different methodologies have been suggested in the literature to simulate the adverse impact of reinforcement corrosion on the non-linear structural behaviour of deteriorated reinforced concrete (RC) structures. The modelling methodology used, however, can significantly bias the predicted time-dependent structural behaviour of deteriorated structures. Considering the critical importance of numerical modelling in bridge maintenance scheduling and effective decision making, the influence of different modelling strategies on the anticipated time-variant structural performance of corroded concrete bridge columns is investigated. To this end, various simple and advanced modelling methodologies are evaluated. The effect of the considered modelling scenarios on the estimation of damage limit states, the sequence of multiple failure modes, structural capacity (both ductility and strength) and energy dissipation capacity of a benchmark circular RC column is evaluated over its service life. The results show that the modelling strategy significantly affects the predicted time-variant structural performance of the deteriorated structure.

In mechanised tunnelling, the filling of the annular gap behind the precast concrete segments is one of the essential operations. The main goal of filling this space is to reduce surface settlements and limit movements due to tunnel excavation in the soil mass. To achieve this aim, a two-component grout is often used to fill the annular gap. Determination of the amounts of ingredients in the two-component grout should be carried out in such a way that the injection materials will be able to fulfil the required performance and technical properties. In this study, laboratory tests were carried out to investigate two-component grout properties, such as flowability, bleeding, gelling time and uniaxial compressive strength. The effect of lateral pressure on grout resistance was studied according to real excavation situations. The influences of the grout ingredients and effective parameters such as bentonite and cement contents, water–cement ratio and the dosage of accelerator (sodium silicate) and accelerator ratio were also investigated.

Bridges are essential components of transportation systems and their unacceptable performance following a disaster may lead to disruption to relief operations. Many existing bridges all around the world were designed based on early editions of seismic codes and the performance of some old bridges following seismic events has revealed that they are seismically vulnerable. This paper provides a comparison of the seismic performance of reinforced concrete (RC) bridges designed according to recent code editions and according to earlier provisions. To this end, a probabilistic seismic safety assessment of RC bridges was conducted. Non-linear response history analyses were performed for each set of bridge samples subjected to earthquake ground motions with different severities employing three-dimensional models. The effect of the earthquake focal mechanism on the seismic vulnerability of the bridges was investigated. Moreover, fragility curves were developed for RC bridges designed according to the latest edition of the American Association of State Highway and Transportation Officials (Aashto) specifications (so-called new bridges) and those designed based on pre-1980 specifications (so-called old bridges). The fragility curves are presented in terms of the geometrical specifications of the bridges and the focal mechanism associated with input motions for both new and old bridges.

Energy flexibility, through short-term demand-side management (DSM) and energy storage technologies, is now seen as a major key to balancing the fluctuating supply in different energy grids with the energy demand of buildings. This is especially important when considering the intermittent nature of ever-growing renewable energy production, as well as the increasing dynamics of electricity demand in buildings. This paper provides a holistic review of (1) data-driven energy flexibility key performance indicators (KPIs) for buildings in the operational phase and (2) open datasets that can be used for testing energy flexibility KPIs. The review identifies a total of 81 data-driven KPIs from 91 recent publications. These KPIs were categorized and analyzed according to their type, complexity, scope, key stakeholders, data requirement, baseline requirement, resolution, and popularity. Moreover, 330 building datasets were collected and evaluated. Of those, 16 were deemed adequate to feature building performing demand response or building-to-grid (B2G) services. The DSM strategy, building scope, grid type, control strategy, needed data features, and usability of these selected 16 datasets were analyzed. This review reveals future opportunities to address limitations in the existing literature: (1) developing new data-driven methodologies to specifically evaluate different energy flexibility strategies and B2G services of existing buildings; (2) developing baseline-free KPIs that could be calculated from easily accessible building sensors and meter data; (3) devoting non-engineering efforts to promote building energy flexibility, such as designing utility programs, standardizing energy flexibility quantification and verification processes; and (4) curating datasets with proper description for energy flexibility assessments., Comment: 30 pages, 14 figures, 4 tables

Building and microgrid designs with highly-distributed electrical storage have potential advantages over today's conventional topologies with centralized storage. This paper studies the capital cost benefits of several residential behind-the-meter distributed-storage topologies, including AC and DC versions of systems with load-packaged batteries and resilient sub-networks. The study begins by defining the block configuration of each topology. This work then develops a model for the cost of the power electronics necessary to interface with the storage elements. Finally, the analysis develops a model for the total cost of each storage topology, incorporating the installation and soft costs. The results suggest that while the cost of power electronics is lower in centralized topologies, the total cost is lower for distributed storage due to the avoided costs of installation and permitting. This paper also explores the benefits of load-packaged batteries for savings in electrical infrastructure.

Peak power demand strains electrical grids and increases cost of electricity generation, transmission and distribution infrastructure. Many studies have examined ways of reducing this peak power demand, including modification of room air temperature setpoints or the reduction of lighting levels. However, very few or no studies have examined the peak power reduction resource offered by temporary curtailment of building ventilation systems. For this reason, we conducted a simulation campaign in which we examined the resource offered by temporary ventilation curtailment in commercial buildings of different use types across the United States and in residences in the state of California, with the essential constraint that any changes resulted in air quality acceptable to occupants through additional ventilation to compensate for the curtailment. To do this, we employed previously validated building models implemented in the airflow and contaminant transport tool CONTAM and building thermal and systems modeling tool EnergyPlus, in some cases co-simulated. Results show savings are highly dependent on building type and climate but range from 0-2 W/ft2 and up to 40% of total peak building power demand. Depending on building type, this power shed can be conducted for 1.5-8 hours before acute exposure or odor concerns are expected, assuming a safety factor of 2. This reduction is of the same magnitude as that offered by thermal control strategies such as setpoint increase, or from lighting reduction strategies.

Fire throttling is the increase in flow resistance due to a large fire in a longitudinally ventilated tunnel. Although the fire throttling effect has been been known and studied for tunnels over the last 40 years, there is not yet a consistent one-dimensional (1D) model that can describe this behaviour or a framework suitable for practical application. We propose a semi-empirical model, based upon pipe flow engineering principles, to describe this effect by separating the resistance to flow, or pressure loses in three parts: upstream of the fire, locally at the fire, and downstream of the fire. The proposed 1D model called TE1D is derived from a simple steady one-dimensional momentum balance in which a semi-empirical mean temperature distribution is assumed across the tunnel. We verify the model by comparing the pressures losses it predicts with those calculated in CFD simulations based on OpenFOAM and Fire Dynamics Simulator. The comparison shows good agreement between the CFD codes for the range of fires sizes considered from 5 to 50 MW and good agreement between TE1D and the CFD results with the proposed 1D model for fire sizes below 30 MW. However, for values above there are large discrepancies between the results obtained by the TE1D and CFD. We posit as a potential explanation that these differences are due to flow and temperature stratification which is not accounted for in the 1D model. The model using pipe flow principles allows engineers to adopt this model for design, together with other pressure losses considered in tunnel ventilation.

This paper presents an analytical approach, based on the limit-equilibrium state, to determine the critical inclination of failure surface and active earth thrust for a cohesive-frictional backfill with a broken slope and a surcharge load at a constant distance from a retaining wall under the seismic condition. A combined analysis using Mononobe-Okabe’s and Culmann’s methods within a trial and error procedure is performed in this study. The influences of several parameters such as wall height, surcharge magnitude, cohesion, and internal friction angle of the backfill, adhesion between the wall-backfill interface, tension cracks, horizontal and vertical seismic acceleration coefficients have been investigated on the critical inclination of failure surface and the active earth thrust. Additionally, the performance of the proposed approach is explored by geotechnical software (Geo5) and two available methods in the literature. All of the results and the detailed comparisons are given in tabular and graphical forms.

To ensure the structural safety and normal operation of a cable-stayed bridge in China (Rainbow Bridge), cables were replaced and construction monitoring and control were conducted. In the process of cable replacements, the cable force and girder elevation were monitored and the distribution of cable force was adjusted according to the construction monitoring results to improve the structural force and increase the safety reserve of the structure. In the process of monitoring the cable force, the difference between the measured cable force and the design cable force was 0.4–4.4%. After adjusting the cable force, the difference between the measured cable force and the design cable force was less than 2%, and the change in the cable force was uniform, meeting the original design requirements. In the monitoring process of the main girder elevation, the elevation was increased by a maximum of 0.054 m. After completing cable adjustment, the main girder elevation was increased by 0–5 mm. This elevation was more reasonable and met the design requirements.

Xinglinpu Bridge was built on the S3801 freeway in 2019 in preparation for the winter Olympics in Beijing, China. It is a cable-stayed steel bridge with pylons in the shape of flower baskets. Using Xinglinpu Bridge as a case study, a systematic approach to the dimensional quality assessment of complex bridges using a combination of three-dimensional (3D) point clouds obtained by terrestrial laser scanning (TLS) and unmanned aerial vehicle (UAV) surveys is proposed in this paper. The currently available methods for dimensional quality assessment of complex bridges rely largely on manual inspection and contact-type measurement devices, which are time consuming and costly. To overcome these limitations, this paper presents a framework for dimensional quality assessment composed of three parts: scanning schemes for TLS and UAV, scanning implementation and measurement of geometric dimensions. The results of configuration detection verified the high-quality construction of Xinglinpu Bridge, although millimetre-scale differences were obtained between the point clouds and the design value. The potential and limitations of 3D laser scanning for assessing the quality of complex bridges are discussed.

The River Dee Bridge is a 270 m long concrete box girder bridge constructed as part of the Aberdeen Western Peripheral Route. The detailed design commenced in 2014, with construction finishing in late 2018. The bridge has a mainspan of 120 m and was built using the balanced cantilever construction method. This paper focuses on the design challenges encountered during the detailed design of this structure, particularly associated with the tight geometrical constraints imposed by environmental and aesthetic considerations on the foundations and the superstructure. The post-tensioned tendon design, which was particularly challenging for this relatively narrow and shallow box section, is also discussed.

This paper sets out the challenges from the perspective of the designer associated with the construction of the River Dee Bridge built by the balanced cantilever method. The importance of managing the construction sequence and its impact on both the design and programme are discussed. Monitoring and managing the loads in the temporary works were crucial to ensuring the stability of the structure. The issues associated with the temporary jacking system and the monitoring adopted are also considered.

To meet the basic requirements of long spans, steel footbridges are generally lightweight structures with low stiffness. Moreover, current trends in innovative structural design have led to more vibration problems related to resonance or quasi-resonance of footbridge structures at typical pedestrian walking frequencies. The present authors apply a feasible methodology to assess the vibration performance of footbridges based on an equivalent beam model developed from a detailed finite-element model and experimental measurements. Free- and induced-vibration tests are performed on a long-span inverted-queen-post-truss steel footbridge located in Rio de Janeiro, which exhibits vibration problems. Pedestrian walking simulations are performed with the simplified footbridge model using a typical dynamic load given from a Fourier series, as well as with a biodynamical formulation that considers human–structure interactions. The equivalent beam model provides a practical means of investigating corrective intervention strategies for the problem of excessive footbridge vibration using tuned mass dampers, and allows the in-service footbridge performance to be assessed based on current standards and design guidelines.

This study investigated the effects of changing the type and surface area per unit mass (Sa) of activated materials on the compressive strength of ground granulated blast-furnace slag (GGBS) cement (GGBS > 60%). This study is divided into two parts. The first part involved the selection of activated materials. Compressive strength results show that gypsum improves the early strength of GGBS cement more effectively than does sodium silicate or sodium hydroxide. The gypsum activators increase GGBS activity through sulfates, generating ettringites and C–S–H to increase compressive strength. Chemical analysis shows that the sulfite (SO3) in GGBS cement has more stable compressive strength at 6–8%. The second part of this study investigated the influence of Sa. Gypsum was used as a strength activator. The sulfite in GGBS cement was controlled at 6.5% ± 0.5%, and Sa was adjusted as the variable. Linear regression analysis shows that the change in GGBS cement Sa (Msa) is positively correlated with compressive strength. The value of Msa can be estimated according to the value of Sa and the quantity of ingredients used for the study results (cement, GGBS and gypsum). The compressive strengths of GGBS cement at various curing ages can be predicted using Msa.

This paper documents performance of cast-in-place reinforced concrete (RC) buildings in the Durrës during Albania earthquake of 26th of November 2019 (MW 6.4). Both mid- and high-rise RC buildings were affected by the earthquake, experiencing structural and/or non-structural damage and even collapse in some cases. The authors performed a reconnaissance study after the earthquake and were involved in seismic assessment of buildings in the affected area. Besides the observations related to physical damage related to RC buildings, the paper also presents results of a statistical analysis of damaged RC buildings in the Durrës city. The discussion in the paper is focused on damage patterns and failure mechanisms that are relevant for the seismic response of RC structures. Most common damage pattern is related to masonry infill walls, which experienced damage and failure in some cases, and affected the performance of adjacent RC columns due to the infill/frame interaction. Taller RC framed buildings (10 storeys and higher) were expected to have RC shear walls; however, these walls were reportedly absent in the damaged buildings of this type. In some cases, masonry infill walls (instead of RC shear walls) were used in the elevator shaft areas, which resulted in inadequate seismic performance. Two case study buildings were presented in detail to illustrate seismic behaviour of cast-in-place RC buildings. The case study is based on field observations after the earthquake and a detailed seismic assessment study. Finally, relevant lessons and recommendations are presented in light of the observed performance of RC buildings.

The need for resilient or sustainable seismic design is at the forefront of structural engineering challenges worldwide. Sustainable seismic design is a relatively new concept that is rapidly gaining interest and hints at the arrival of the next generation earthquake engineering practice. In the present context ‘sustainable seismic’ refers to structural operability with a view to post-earthquake realignment and repairs. Experience has shown that it is cost inhibitive to elevate the status of conventional earthquake-resistant structures to seismic sustainability by means of traditional methods of design and construction. This paper introduces two simple analytic concepts, performance control and design led analysis, that lead to the development of sustainable seismic designs for purpose-specific archetypes. Seismic energy control, global stiffness reduction and restoring force adjustment are introduced as relatively simple methodologies that help achieve efficient post-earthquake realignment and repairs. Combinations of structures of uniform response and rigid rocking cores are used as ideal models for sustainable seismic design. Three simple technologies, the replaceable energy dissipating moment connection, the energy-dissipating grade beams and the hybrid rocking–stepping core, are also introduced. Several parametric examples are provided to demonstrate the applications of the proposed methodologies.

In situ ground improvement by deep mixing the soil with stabilising agents or binders as lime, cement, cement kiln dust or a combination of these is the most common method applied in the Nordic countries. In Norway, soil stabilisation with deep mixing has been applied to soft-to-medium stiff clays with sensitivity ranging from about 5 to over 100. This paper presents a large database of laboratory results from laboratory-stabilised Norwegian clays. For example the data show that shear strength of the stabilised clays decreases when the water-to-binder ratio (i.e. total clay water-to-binder content ratio) increases, and that the stiffness development is mainly controlled by time. Some observations from more advanced laboratory testing on samples taken from stabilised columns in the field highlight the anisotropic behaviour of the stabilised clays and the increase in strength with in situ stresses. The data presented can be used as a guide on the selection of binder mixes for specific project applications and it should always be supplemented by testing on site-specific laboratory-mixed specimens.

Since the terrorist attacks on 11 September 2001, structural resistance to explosion has received increasing attention. As bridges are controlling factors in traffic systems, explosion-induced bridge damage will cause great economic loss and social impact, but there is a lack of anti-explosion research for bridges. The purpose of this work was to investigate the failure modes and safety distances of cylindrical reinforced concrete (RC) bridge piers on highways and urban viaducts as a result of vehicle explosion. TNT equivalents were selected to represent explosions of five different vehicles (car, sport utility vehicle/van, delivery truck, water truck and semi-trailer). The multi-Euler domain method, was adopted for structural analysis of the explosion process using the commercial software Autodyn. The results showed that RC piers have three failure modes at the base: full-section punching-shear failure and large displacement; shear failure of full-section concrete; local shear failure of concrete. The explosion energy decayed rapidly with distance. For the five vehicle explosions, the safety distances were found to be 2 m, 3 m, 4 m, 8 m and 14 m, respectively. The results of this work are meaningful for explosion-resistant design and damage assessments of existing highway cylindrical RC piers subjected to vehicle explosion.

This paper presents a collaboratively adaptive vibration monitoring system that captures high-fidelity structural vibration signals induced by pedestrians. These signals can be used for various human activities’ monitoring by inferring information about the impact sources, such as pedestrian footsteps, door opening and closing, and dragging objects. Such applications often require high-fidelity (high resolution and low distortion) signals. Traditionally, expensive high resolution and high dynamic range sensors are adopted to ensure sufficient resolution. However, for sensing systems that use low-cost sensing devices, the resolution and dynamic range are often limited; hence this type of sensing methods is not well explored ubiquitously. We propose a low-cost sensing system that utilizes (1) a heuristic model of the investigating excitations and (2) shared information through networked devices to adapt hardware configurations and obtain high-fidelity structural vibration signals. To further explain the system, we use indoor pedestrian footstep sensing through ambient structural vibration as an example to demonstrate the system performance. We evaluate the application with three metrics that measure the signal quality from different aspects: the sufficient resolution rate to present signal resolution improvement without clipping, the clipping rate to measure the distortion of the footstep signal, and the signal magnitude to quantify the detailed resolution of the detected footstep signal. In experiments conducted in a school building, our system demonstrated up to 2× increase on the sufficient resolution rate and 2× less error rate when used to locate the pedestrians as they walk along the hallway, compared to a fixed sensing setting.

Grease, oil, hydrocarbon residues, heavy metals, and surfactants are all present in car wash wastewater (CWW), which all can have detrimental effects on the environment and human health. This study was designed to assess CWW treatment using an upgraded physical technique combined with a range of conventional and more sustainable coagulants. Physical treatment effectively lowered the oil and grease (O&G) and chemical oxygen demand (COD) of the CWW by 79 ± 15% and 97 ± 1.6%, respectively. Additional treatment was provided using chemical coagulation–flocculation–settling. In jar test studies, humic acid (HA) and alum were found to provide significantly higher turbidity removal, 79.2 ± 3.1% and 69.8 ± 8.0%, respectively, than anionic polyacrylamide (APA), 7.9 ± 5.6% under influent turbidity values from 89 to 1000 NTU. Overall physical/chemical treatment of CWW yielded 97.3 ± 0.8% COD removal, and 99.2 ± 0.4% O&G removal using HA and alum. Due to the numerous problems created when using synthetic coagulants, naturally occurring coagulants that have no impact on human health, such as HA, are highly desirable options. The findings of this study show that treating CWW provides several advantages for sustainable development, health and well-being, and raising public knowledge and support for water reuse.

This study set out to identify emerging trends in advancing engineering for sustainable development, supporting the engineering workforce to address wicked problems, and strengthening pathways between engineering education, industry, and policy. The following question guided this work: What are the emerging factors impacting the future of global sustainability efforts within engineering, and how can these be amplified to increase the impact of engineering for sustainable development? Using an adapted Delphi method with surveys, focus groups, and member-checking interviews, we hosted the American Society of Mechanical Engineers (ASME) 2022 Engineering Global Development (EGD) Stakeholder Summit. The summit convened industry leaders, innovators, and academics to explore emerging factors impacting the future of global sustainability efforts in engineering. This manuscript synthesizes emerging trends and proposes recommendations for engineering, particularly in the specific focus area of engineering for sustainable development (e.g., ‘humanitarian engineering’, ‘global engineering’). Critical recommendations include the adoption of emerging cultural mindsets, which include: (1) take an interdisciplinary and multi-stakeholder approach, (2) consider dynamic and interconnected systems, (3) increase humility and intercultural competence, (4) prioritize diversity and inclusion, (5) increase localization and center community perspectives, (6) challenge the perception that engineering is neutral, and (7) broaden the goals of engineering. Ultimately, this study highlights pathways forward for the broader engineering community to more effectively contribute to advancing the United Nations Sustainable Development Goals. Published version

This work investigates the acoustic characteristics of the double elliptical vault, which overlooks the Grand Staircase of the Royal Palace of Caserta (Italy). The Royal Palace was built by the architect Luigi Vanvitelli in the Seventeenth Century and it is the largest royal building in Italy. The double elliptical vault presents a great scenography effect. Inside the vault, on the planking level, musicians used to play for the king and his guests when the royal procession, going up the grand staircase, entered the royal apartments, creating astonishment among the guests who heard the music without understanding from where it was coming. Since the musicians were inside the vault, the long reverberation made the listeners perceive the vault to be enveloped by the music. To investigate this effect, the acoustic characteristics of the double vault were measured, putting the sound source on the planking level of the vault, while the microphones were put along the staircase and in the vestibule towards the royal apartments. Finally, the spatial distribution of several acoustic parameters is evaluated also using architectural acoustic simulations.

Within the context of sustainable innovation in the building industry, the goal of this study is to investigate and discuss forms of cooperative learning in project organizations as an opportunity for realizing sustainable innovation. This paper analyzes 30 worldwide cases of sustainably innovative building projects, concentrating on the cooperative learning behavior of actors that ignite and contribute to sustainable building innovation. The analysis sheds light on three clusters of project organizations, their typical cooperative learning processes, and the cooperative sustainable learning effects achieved. Theoretically, this work contributes by suggesting an analytical model to study learning forms that support sustainable building innovation; practically, this study indicates that cooperative learning practices facilitate professionals, regardless of their role in project organizations, to be innovators in proposing and achieving green innovation in the construction engineering sector.

The aim of this paper is to present the different effects of reinforcement corrosion on reinforced concrete buildings. A hypothetical five-storey reinforced concrete building frame was designed for this purpose. Three different modes of action were selected – corrosion on the ground floor alone, corrosion on one facade and corrosion on two neighbouring facades of the building. For each mode of action, different corrosion scenarios were selected, which were arranged in terms of mass loss from zero to 15% in ascending order an in 3% steps. Pushover analyses of the building were performed for each corrosion scenario and the results of these analyses were used to perform a structural performance evaluation conforming to Eurocode 8. A general decrease in structural performance was determined with significant changes in the dynamic characteristics of the building. The level of decrease depended on the corrosion scenarios and the modes of action. Important structural behaviour alterations and premature damage occurrences were found, in addition to a reduction in the displacement ductility of the building. For severe-corrosion scenarios, reductions in moment and curvature capacities could shift the structural behaviour of the load-bearing members from ductile to non-ductile.

Issues related to readability risks in contracts could exacerbate conflict, claim and dispute occurrences in construction projects. Determination of root causes of readability risks by defining casual relationships in construction contracts is essential to improve contract documentation and enable successful risk management. This paper aims to differentiate net causes from net effect factors of readability risks in construction contracts. Most significant readability risks in construction contracts were analyzed using fuzzy decision-making trial and evaluation laboratory (DEMATEL) method, which is known for its wide implementation in similar problems. Root cause degree (RCD) diagram was drawn to illustrate the differentiation of these factors by adopting maximum mean de-entropy (MMDE) algorithm. Analysis results indicated that poor grammar use, legal terminology, visual representation, and negative language were the major underlying cause factors; while lengthy document, use of abbreviations, scope complexity, controversial uses, repetitions, and ambiguous words were the net effect factors. The results are expected to improve readability of contract documents, which would contribute to more effective risk management and better allocation of project resources.

The aim of this study is to assist the safety specialists and departments in ready mixed concrete (RMC) industry by preparing an internal safety evaluation program (ISEP). To constitute an ISEP the 287-item control list was created and grouped as negligible, moderate, and critical. The control list was applied to thirteen RMC plants which belongs to one RMC company. It is found that even the same company cannot ensure stability in terms of OHS between its plants, none of the plants had an approved OHS policy, emergency action plan and a plant entrance OHS warning sign. OHS training was mostly missing in plants.

This paper presents a case study of the condition evaluation, structural assessment and durability analysis of the Al Maktoum bridges in the UAE to provide assurance that they will meet their 100-year service life. It is considered that this holistic analysis is the first of its kind in the UAE. The project included a detailed structural assessment utilising three-dimensional finite-element methods. The analysis indicated that the stresses in all the critical elements were well below the yield limit. The results of the structural assessment were used in combination with the durability assessment to inform the life cycle cost analysis and asset maintenance strategy. The durability analysis incorporated a probabilistic assessment method to verify the remaining service life of the structures. This method utilised a 90% confidence level using the fib Model Code for Service Life Design. The results of modelling were verified against the inspection and testing results, which included concrete strength tests, half-cell potential mapping and chloride ion sampling. Overall, this project case is the first of its kind in the UAE and provided a platform of asset management strategy implementation to establish the current condition of the structures, assess their structural integrity and verify their remaining service life.

This paper presents the results of an experimental evaluation of masonry grout made with lime-activated slag–glass powder blend as a binder. The purpose of this study is to develop a grout mixture that is low-carbon dioxide (‘low-carbon’) and has the potential to replace the traditional grout material used in load-bearing concrete block masonry construction. Traditional grout material uses Portland cement, production of which is responsible for a large proportion of carbon dioxide emissions. Thus, elimination or even reduction in the use of Portland cement will minimise environmental impacts. Three grout mixtures incorporating different proportions of glass powder as a partial replacement of slag as an aluminosilicate precursor were investigated to determine the optimum mix proportion that yields the desired properties of the grout material used in concrete block masonry construction. The workability, compressive strength and permeability properties of the mixtures were evaluated. Results from this study show that the use of glass powder at 25% replacement of slag as a precursor in the binder system provides the best performance, and that this mixture can be successfully used as an alternative and low-carbon grout material for concrete block masonry construction.

Today, there is a growing interest in developing energy efficient buildings since it is estimated that buildings account for about 40% of the total primary energy consumption in the world. In relation to existing buildings, energy efficiency retrofits have become an important opportunity to upgrade the energy performance of commercial, public and residential buildings that may reduce the energy consumption, demand and cost. In this paper we cover the energy efficiency deep retrofit process that has been carried out for Nottingham Playhouse theatre building for the aim of enhancing its environmental performance and analysing the energy efficiency gained after implementing certain proposed modifications. It is a nationally protected historic building, listed as Grade II∗ on The National Heritage List for England (NHLE). The building has had insulation enhancement, doors modifications, solar energy installations, energy-saving lights, in addition to improved heating and air conditioning system. The paper presents a novel methodology; and its results indicate significant improvements in the building's energy performance which is demonstrated using infrared thermographic images and data logger sensors where significant energy savings to the building's thermal performance are obtained. The energy saving measures have been completed while maintaining the heritage building's general appearance and architectural features, which have received a Commendation Certificate from The Nottingham Civic Society for this achievement.

This paper describes the influence of fly ash on the swell-compressibility characteristics of an expansive clay passing through a 4·75 mm sieve. The free-swell index (FSI), heave, swell potential, swelling pressure, coefficient of compressibility (av), the compression index (Cc) and linear shrinkage (LS) of fly ash–clay blends were studied. Fly ash content was varied from 0, 5, 10, 15 to 20%. Swelling and compressibility of the clay decreased with increasing fly ash content. Heave was the lowest at 15% fly ash. The paper compares the effect of 15% fly ash on the swell-compressibility behaviour of clay lumps passing a 4·75 mm sieve and clay powder passing a 425 μm sieve. While the swell potential was found to be higher for clay powder than for clay lumps at 15% fly ash, the swelling pressure was higher for clay lumps. As 4% lime resulted in the highest reduction of the FSI, a series of swell-consolidation tests and a series of FSI tests were conducted on fly ash–clay blends to which 4% lime was added. FSI, heave and swelling pressure decreased on the addition of fly ash. They further decreased when 4% lime was added. The parameters av, Cc and LS also reflected a similar trend.

Marine clay is commonly found worldwide and is challenging to work with from a geotechnical and geoenvironmental perspective due to its diverse characteristics, such as high compressibility and sensitivity. There is therefore a need to seek effective treatment solutions that are less environmentally harmful than traditional methods. The aim of this research study was to assess the performance of marine clay treated with a binder incorporating Portland cement, hydrated lime and copper slag. Unconfined compression and split tensile tests were carried out to assess the distinct binder content effects and to correlate those responses with the porosity/binder index. Moreover, scanning electron microscopy was conducted to study the microstructure of the mixes containing copper slag. The results showed that the addition of lime, the dry unit weight and the curing period were the most influential factors regarding the strength of the mixtures, in that order. In addition, good correlations were obtained between the strength and the adjusted porosity/binder index for all mixtures.

Stabilisation of expansive soils with various additives such as lime and fly ash has been shown to be a viable technique to counteract heave and shrinkage. This paper presents experimental results obtained from tests performed on expansive clay beds with fly-ash-stabilised clay cushions of varying thicknesses and fly-ash content. The amount and rate of heave, swelling pressure and stress–settlement characteristics of the expansive clay beds were studied. The results indicated that when fly-ash-stabilised clay cushions were provided over expansive clay beds, heave and swelling pressure decreased in comparison with the heave and swelling pressure of untreated expansive clay beds but, heave and swelling pressure increased with increasing fly-ash content for a given thickness of the cushion. For a given fly-ash content, however, heave and swelling pressure decreased with increasing thickness. Heave reduced by 70% when a 75 mm thick clay cushion stabilised with 10% fly-ash content was used. The stress–settlement characteristics of the expansive clay beds with a fly-ash-stabilised clay cushion improved. The settlement of the footing on a 50 mm thick clay cushion decreased by about 43% when the fly-ash content was increased from 0 to 10%.

Prestressed hollowcore slabs are potentially critical segments in the construction sequence of a precast concrete structure, in which very early age strength is vital for ensuring factory productivity. Importantly, the construction industry is striving to reduce concrete's carbon footprint by using Portland cement substitutes, particularly using ground granulated blastfurnace slag (GGBS) in Ireland. This paper investigates the early age strength enhancement methods for slag-concrete mixes, in order to address the well-known retarding effects arising from slag's inclusion. The strength enhancement methods, including temperature curing and a novel accelerating admixture, are used to activate the slag in the concrete mixes, with replacement rates up to 50% GGBS. The efficacy of these methods is investigated in relation to establishing the development of compressive strength and modulus of elasticity over time (being relevant to stress transfer), particularly at very early and at later ages for strength compliance. The study demonstrates the potential for using up to 50% GGBS mixes for slab production while still maintaining the strengths sufficient to achieve existing productivity targets in precast concrete production.

High strength aluminum alloy members can be used if the required cross-sections are larger than those obtainable by extrusion. The application range of the current design codes for aluminum structures is limited for normal-strength material and whether high-strength members can be designed with the existed buckling curves is examined. Fourteen H-section columns made from 7075-T6 were tested under axial compression. The effects of the different material properties and imperfections on the flexural buckling behavior of normal- and high-strength columns were analyzed numerically. The column curves in European, Chinese and American specifications can predict flexural buckling resistance of such columns safely with an average underestimation of 13%, 12% and 8%, respectively. Eighty-one column buckling tests available in the literature performed on extruded sections made of aluminum alloy with the yield stress between 388 MPa and 557 MPa were collected and analyzed. Finally, a new flexural buckling curve was suggested for the estimation of flexural-buckling resistance of high-strength extruded members.

Seismic isolation systems exposed to far-fault earthquakes can reduce floor accelerations and story drift ratios to acceptable levels. However, they exhibit different structural performances in each earthquake due to different excitation frequency contents. By optimizing the isolation system parameters, their performance may be maintained at the best level under different far-fault earthquakes. In this study, the optimization of the parameters of the nonlinear isolation system of a 5-story benchmark building is performed by Teaching-Learning Based Optimization (TLBO) algorithm to minimize peak floor accelerations under historical far-fault earthquakes with and without exceeding a specified base displacement limit. According to the results of the analyses, it can be said that TLBO algorithm is a robust algorithm with low standard deviations for determining optimum nonlinear isolation system parameters.

Stainless steel reinforcing rebars and prestressing strands are viable alternatives to carbon steel materials for prestressed concrete structures in extremely aggressive environments. They offer better durability and require less maintenance. This study experimentally investigated the transfer length and prestress losses of 15.2-mm- (0.6-in.-) diameter Duplex High-Strength Stainless Steel (HSSS) strands as well as the shear and flexural behavior of two full-scale 12.8-m- (42-ft-) long AASHTO Type II concrete girders prestressed with HSSS strands and reinforced with duplex stainless steel rebars. The girders were made composite by adding a deck slab. One girder was tested in shear at both ends while the other girder was tested in flexure. Experimental shear and flexural behavior of the girders exhibited a constant increase in load carrying capacity up to failure. The failure mode for the shear tests was web shear, and for the flexural test was rupture of the HSSS strands. Both girders tested in shear and flexure failed in a progressive manner as they exhibited adequate warning through noticeable deflection, excessive cracking, and large reserve strength from first cracking to failure. The applicability of AASHTO LRFD provision for stainless steel reinforcing materials was investigated. AASHTO LRFD equations for flexural resistance were modified to cover rupture of strand failure mode. Experimental shear strength and flexural strength of the girders were greater than the predicted values by AASHTO shear equations and modified AASHTO flexural equations, respectively.

A ‘locking-bolt’ demountable shear connector (LBDSC) is proposed to facilitate the deconstruction and reuse of steel-concrete composite structures, in line with achieving a more sustainable construction design paradigm. The LBDSC is comprised of a grout-filled steel tube and a geometrically compatible partially threaded bolt. The latter has a geometry that ‘locks’ the bolt in compatible holes predrilled on the steel flange and eliminates initial slip and construction tolerance issues. The structural behaviour of the LBDSC is evaluated through nine pushout tests using a horizontal test setup. The effects of the tube thickness, strength of concrete slab, and strength of infilled grout on the shear resistance, initial stiffness, and ductility of the LBDSC are assessed. The experimental results show that the LBDSC can achieve higher shear resistance and similar initial stiffness as compared to traditional welded studs. In addition, all tested LBDSCs exhibited slip capacities ranging from 14 to 32 mm and can be classified as ductile shear connectors according to Eurocode 4. A detailed finite element model was also created and found to be reliable to reproduce the experimental behaviour. Parametric studies were subsequently conducted using the validated model to study further parameters and generalise the experimental results. Due to the specific test setup, non-negligible uplift forces were generated in the connector and the potential implications are discussed.

This paper investigates the accuracy of different design equations given in design specifications and literatures in determining the block shear strength of the lean duplex stainless steel fillet welded connections with base metal fracture. It points out the problem inherent in the block shear provision specified in the North American cold-formed design specification, which does not consider shear strain hardening. The previous test results have found that full shear strain hardening can be assumed for the carbon steel and ferritic stainless steel welded connections, but not applicable to the thin-walled lean duplex stainless steel welded connections with a higher ratio of the tensile strength to yield stress. Based on the results of finite element analysis including ductile damage simulation, this study reveals that the block shear strength of the lean duplex stainless steel specimens can be determined accurately using the mean between the shear yield stress and the shear ultimate stress. This paper also investigates the effect of stress triaxiality incorporated in the block shear equations found in the literature through comparative analysis with the bolted connection. The effect is shown to be negligible for the thin-walled lean duplex stainless steel welded connection, although higher stress triaxiality is developed in welded connection than in bolted connection. This paper recommends a block shear equation assuming the normal tensile stress in the net area in conjunction with partial shear strain hardening. The recommended equation was found to be more accurate than other equations for determining the block shear strength of the thin-walled lean duplex stainless steel welded connections.

This paper expounds the classification, modelling and preparation methods of curved plates in China and emphasises the characteristics and application examples of various forming methods for developing a bionic curved plate. The forming methods of curved plates can be divided into three major categories – stress forming, solidification forming and composite forming. The integrated classification system of a curved plate is given in this paper. Due to the complexity of surface morphology and preparation methods, the creation of a systematic classification of surface plates and their preparation methods remains an area for further study. The characteristics of various stress forming methods are explained, providing a beneficial reference for engineering applications. However, these methods are dependent on the operator's experience and a future research topic is to promote mechanisation, automation and intelligence. Several engineering application examples and the identification of solidification forming are described, which provide a direct reference for buildings with tall and complex curved surfaces. How to develop common and individual technologies for curved plate forming will be the research focus of curved plate forming methods in the future.

This paper carried out an experimental study and numerical analyses on 6082-T6 aluminium alloy columns under eccentric loading at elevated temperatures. The mechanical properties of standard specimens were obtained from tensile tests performed at different temperatures. Thirty-two aluminium alloy columns were tested under eccentric compression at elevated temperatures to determine their corresponding bearing capacity. The experimental results showed that overall bending buckling occurred in all column specimens and that the bearing capacity of the specimens decreased with increasing temperature and eccentricity. Based on simulations of finite element (FE) models with different section dimensions and normalized slenderness ratios, the buckling bearing capacity and correlation curves of 652 aluminium alloy columns under eccentric compression were obtained. This paper proposed a new correction coefficient that can be used for design formula modification. The results can be seen that all the numerical curves are above the linear correlation curve and the proposed design formula was found to be suitable and effective through comparisons between the FEA results, test results and the modified correlation curve at different temperatures. Additionally, reliability analysis has also been conducted to evaluate the reliability level of the proposed design method for aluminium alloy columns at elevated temperatures.

Lateral restrainers are traditionally provided in reinforced masonry (RM) walls to prevent the vertical steel bars from buckling. In the current version of the Australian Masonry Standards (AS 3700–2018), the use of lateral restrainers in RM walls is relaxed, if the vertical rebars are surrounded by grout annulus of twice the diameter of the bars. However, it is challenging to maintain the verticality of the reinforcing bars in the block cores to satisfy the grout annulus requirement without lateral restrainers. To address this challenge, restrainer bar chairs can be used in the construction of RM walls which are easier to employ in comparison to lateral restrainer ties. However, the implications of adopting restrainer bar chairs as an alternative to restrainer ties in RM wall construction are not well verified. In this study, the influence of restrainer bar chairs and conventional lateral ties restraining methods on the axial compression and out-of-plane bending characteristics of RM walls have been investigated. In total, twelve RM walls of dimensions 1390 mm height × 590 mm length × 190 mm thickness were constructed and tested, of which, four walls each were tested under concentric and eccentric compression and four-point bending. The experimental results revealed that the performance of RM walls with restrainer bar chairs and conventional lateral ties were similar, in terms of the observed failure modes, strength, load–displacement characteristics obtained under both compression and out-of-plane loading conditions. Strain measurements on rebars indicated that a composite action was ensued in both restrainer configurations. The capacities of the RM walls under compression and out-of-plane bending were also verified with three different masonry standards provisions and were found adequate with reasonable safety. Overall, it can be concluded that the restrainer bar chairs can effectively be used in RM walls to enable quick and accurate vertical positioning of the rebars and ensure adequate grout annulus around them.