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The complexity of large-scale bridge construction necessitates continuous monitoring to perform quality assurance and control, both of which have a great influence on structural performance and durability. Conventional approaches to monitoring bridge construction heavily rely on human inspection and expert judgment performed on-site by trained technicians. However, these often lack the required spatial and/or temporal resolution in the obtainable data, and are inefficient and potentially dangerous for the operators. In this context, the development of automated systems and advanced sensing solutions brings the opportunity to enhance accuracy and efficiency, minimize human error, and mitigate safety risks. Laser scanning technology, known for its precision in target representations, combined with uncrewed aerial vehicles (UAVs) serving as multifunctional sensor platforms, are a promising means for safe and efficient monitoring of bridge construction. This manuscript presents an experimental case study focused on the application of UAV-based LiDAR-RGB data fusion for bridge reconstructions, to assess their effectiveness in monitoring bridge construction. Four-dimensional models of the bridge were constructed based on data collected via LiDAR and photogrammetry. The models generated with the two approaches then were compared formally with the target design values to ascertain their accuracy. The results demonstrate that construction monitoring strategies that only rely on photogrammetric information can provide results with insufficient accuracy, particularly in terms of the integrity of the three-dimensional (3D) reconstructions and the accuracy of the geometry and slope of the bridge superstructure. In contrast, LiDAR-RGB data fusion can provide precise and comprehensive spatial information on bridge construction, such as global and local geometry of the bridge and information on the positioning of different structural elements in the deck, which can significantly benefit construction management and construction quality assessment and control. [ABSTRACT FROM AUTHOR]

The study is focused on the application of artificial intelligence (AI) in the construction and erection of monolithic reinforced concrete structures in the Far North and Arctic zone, with the aim of managing potential risks. The topic deals with various ways required to mitigate risks associated with the unique climatic and weather conditions of these regions. The objective of this study is to develop a methodology for forecasting and risk management using AI. In this study, data on construction processes and potential risks in Far North and Arctic zone conditions was utilised. The methodology is based on the application of artificial intelligence algorithms for data processing and analysis. The study resulted in the proposal of an AI-based risk management methodology. This methodology enables the prediction of potential issues and comprehensive risk management at all stages of construction and erection of monolithic reinforced concrete structures. The application of AI in construction risk management in the Far North and Arctic zone increases the efficiency and safety of construction processes. The use of the developed model is recommended for risk minimization and optimization of construction in complex climatic conditions. [ABSTRACT FROM AUTHOR]

Food security is an important guarantee for national security and public health. Underground reinforced concrete (RC) grain silos can provide a quasi-low temperature environment for grain storage, effectively ensuring the quality of the stored grain. The stress status of the underground silo during soil backfilling construction is complex, which puts the structure at risk of failure. The present study developed a numerical simulation method to investigate the mechanical properties of underground silos during backfilling construction processes. A finite element (FE) analysis of the backfilling construction process of an underground RC grain silo was conducted, and the nonlinear contact between the underground silo and the surrounding soil, as well as the material nonlinear behavior of the soil, was considered. The deformation characteristics and stress distribution of the underground silo during the backfilling construction process were revealed. The results indicate that the underground RC grain silo exhibits good mechanical performance. The underground silo underwent overall settlement during the backfilling construction process, with a total settlement of 21 mm. The maximum radial displacement of the silo wall and the maximum deflection of the radial primary beam were 0.84 mm and 5.67 mm, respectively, both of which were smaller than the limit values. After the completion of backfilling construction, there was a high risk of concrete cracking of the silo wall. The maximum radial and circumferential tensile stresses of the concrete at the silo top were both high, which led to cracking in the top of the silo. Our research results provide important support for the design and evaluation of underground RC grain silos. [ABSTRACT FROM AUTHOR]

During the long-term operation of hydraulic structures under the action of complex loads and impacts, non-design changes occur, which lead to a decrease in the bearing capacity and safety and, accordingly, to the need for structural reinforcements. Experiments were conducted to study the strengthening of reinforced concrete models of hydraulic structures with interblock construction joints (located in two directions) and with the low longitudinal reinforcement coefficients typical of hydraulic structures (μs = 0.0039 and μs = 0.0083), using the low concrete classes B15 and B25. These structures were strengthened using external reinforcement with carbon ribbons of the FibArm 530/300 type. The results revealed an increase in the bearing capacity (by 1.355- and 1.66-fold); accordingly, the high efficiency of this strengthening method for reinforced concrete hydraulic structures was proven. Using the results of these experiments, including the obtained special characteristic of the cracking of reinforced concrete structures and the results of studies by other authors, recommendations for calculations involving reinforced concrete hydraulic engineering structures strengthened with an external reinforcement system of carbon-fibre-based composite materials were developed and proposed. Carbon-fibre-based composite materials are used as elements of external reinforcement for building structures (unidirectional—tapes, bidirectional—meshes and fabrics). The calculation recommendations proposed by the authors can be taken into account for the creation of a regulatory framework for hydropower facilities, including hydroelectric power plants and pumped-storage power plants. They justify the use of an external reinforcement system made with carbon-fibre-based composite materials to strengthen hydraulic structures in operation and provide an increased level of safety for reinforced concrete structures and constructions. [ABSTRACT FROM AUTHOR]

The presents study numerically investigates the fiber-reinforced polymer (FRP) retrofitted shortdamaged reinforced concrete (RC) columns subjected to axial compression load. The main parameter considered to evaluate the effectiveness of FRP retrofitting on circular columns with different aspect ratios, concrete grade, and FRP material. To simulate the behaviour of a short RC column under a uniaxial compression load, a finite element model of the column was developed. The model was then modified to simulate the various level of damage to the column and the behaviour of the column under uniaxial load. The effectiveness of FRP retrofit was studied comparing the behaviour of the retrofitted column to the damaged column. For M20 concrete column retrofitted with carbon fiber reinforced polymer (CFRP) showed a higher strength (2 to 3 times) than glass fiber reinforced polymer (GFRP) retrofitted columns. For M30 concrete, the range is quite similar (1.5 – 2.3 times more). The effectiveness of both FRPs retrofitted columns increases with increasing aspect ratio from 2 and 3, but slightly decreases for an aspect ratio of 4 compared to the damaged specimen. The maximum effectiveness achieved for CFRP retrofitted columns is of 19.45% and for GFRP retrofitted column is of 10.71%, and the other grade of concrete (M30) followed a similar trend. The load-bearing capacity of columns has no significant effect by the increase in aspect ratio from 2 to 4. [ABSTRACT FROM AUTHOR]

Copyright of Railway Construction Technology is the property of Railway Construction Technology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Reinforced concrete structures constructed in coastal areas in Indonesia often suffer damage before reaching their intended service life, with steel reinforcement corrosion being a major contributing factor. This study aims to investigate the use of concrete structures produced with simple methods and inadequate supervision in coastal regions. Reinforced concrete structures near the coast are susceptible to carbonation due to marine environmental factors, leading to reinforcement corrosion. The study was conducted on the Dande Dandere Market building, Tanakeke Island, Takalar Regency, South Sulawesi. The research method employed quantitative techniques, including surveys and structural testing. Visual inspections were conducted to identify the types of damage present in the building and estimate their causes. Structural testing involved both destructive and non-destructive tests. Concrete compressive strength testing was also conducted to assess the concrete sample's compressive strength, along with carbonation testing to determine the acidity level of concrete due to the intrusion of salt compounds or carbonation formed within the concrete mass. The research findings indicate structural degradation in the market's construction, occurring more rapidly than the intended lifespan of the building. Signs of structural degradation in the reinforced concrete construction include spalling of concrete cover on beams, supporting columns, and cantilever slabs, as well as degraded reinforcement, with an average reduction in steel weight of 62.70% over six years, and an average weight loss of 0.103 grams per day. Therefore, efforts are needed to optimize the structural quality of the building through comprehensive repairs, starting from the foundation. However, for cost-efficient alternatives, it is recommended to use timber structural materials for new market construction. The use of timber in coastal buildings, which are vulnerable to marine influences, is more feasible as the presence of saltwater can inhibit wood decay caused by microorganisms. [ABSTRACT FROM AUTHOR]

Summary: The automated identification of building characteristics for seismic vulnerability remains a challenge for governments due to the high number of buildings in cities. The diverse architectural styles of these buildings complicate the automated identification of building information (e.g., number of stories, structural system, and material type). Deep learning techniques lose accuracy as they generalize information, while the visual contents of a building exhibit a considerable range and diversity. This study leverages the pose detection technique to tackle such issues by focusing on a common construction style: reinforced concrete buildings representing columns, beams, or floors on the façade. With an aim to enable the assessment of seismic vulnerability, the technique developed herein is conceived for buildings with up to six stories that are more likely to be moment‐frame buildings. The AI‐enabled proposed framework starts with collecting building images and categorizing those containing this specific building type. A bounding box detector is then used to isolate building facades, for the subsequent identification of the structural frame with the High‐Resolution Network (HR‐Net). For demonstration, we illustrate this technique by identifying the structural frame on concrete buildings with a sample dataset developed based on buildings found in Mexico City in a pre‐earthquake event state. [ABSTRACT FROM AUTHOR]

This study aimed to analyze the deflection behavior of reinforced concrete beams with a spacing of 3/4 of the effective beam height. This research is a laboratory experimental study with a design of 6 (six) test objects consisting of 3 (three) normal beams (BN) as control variable beams and 3 (three) reinforcing beams of the frame system with a spacing of 0.75d (BTR75 ) as the independent variable. Data were analyzed using the strength design method. The results showed that the deflection behavior of reinforced concrete beams with a spacing of 3/4 of the effective beam height (BTR75) had better serviceability and increased the flexural capacity of Mu beams up to 4.60% and reduced the amount of deflection of the beam BN. [ABSTRACT FROM AUTHOR]

In this work, a series of durability requirements are proposed for the construction of long-service-life reinforced concrete (RC) structures in a coastal environment with extreme atmospheric corrosivity. RC specimens were exposed in a coastal outdoor site in Cuba for three years. Carbon steel corrosion evaluation revealed an annual average atmospheric corrosion rate over the maximum limit established (ISO 9223:2012) for extreme (CX) atmospheric corrosivity. The service life of the RC structures, considered as the sum of the time-to-corrosion-initiation and time-to-corrosion-induced concrete cracking, was determined as a function of durability requirements. The most important durability requirements to achieve a long service life (>70 years) in RC structures subjected to a CX corrosivity category were defined as follows: water/cement ratio, compressive strength, percentage of effective capillary porosity, and concrete cover thickness. Under these hostile environments, the expansion of the corrosion products formed on the reinforcement steel and the induced cracking of the concrete could be attributed partially to the formation of the akaganeite phase in reinforcement steel, which revealed a different morphology compared to the akaganeite typically formed in bare carbon steels. [ABSTRACT FROM AUTHOR]

Copyright of New Architecture is the property of New Architecture Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The condition evaluation for reinforced concrete framing requires comprehensive analysis of the factors influencing their performance such as strength, protective layer thickness, rebar diameter, thermal conductivity, humidity, adhesion of coatings, etc. Non-destructive methods are especially relevant when the characteristics of concrete and rebars are unknown and the scope of testing is considerable. Non-destructive testing allows to effectively monitor the conditions of technical devices, structures and buildings and enables to evaluate the timeliness and quality of repair and maintenance of a facility. Non-destructive testing provides the most reliable characteristics of the parameters defining the technical condition of the facilities under test. Non-destructive testing of the structural strength is applied in those areas, which have been exposed to loads due to natural and man-made contingencies. [ABSTRACT FROM AUTHOR]

Alton Apartment is a high-rise residential building. The city of Semarang, within a radius of 500 km, has a fault range with a strength of up to 8.3 magnitude. The purpose of this study is to calculate the performance level of the structure, find out the nonlinear static procedure conditions and whether the analysis results can be used, calculate the value of ductility R, check the boundaries between levels, check the influence of P-delta, adjust horizontal irregularities, and check the vertical irregularity conditions. This study uses the FEMA 356 method. New regulations are used in the analysis, such as peak acceleration maps and response spectra from PuSGeN in 2021, deaggregation maps of Indonesian earthquake hazards for planning and evaluation of earthquake-resistant infrastructure from the Director General of Cipta Karya in 2022, and earthquake resilience planning procedures for building and non-building structures from SNI 1726-2019. The result of the structure performance of the drift value is below 1% for the life safety (LS) performance level on the 250-year earthquake map, and the result of the drift value is below 2% for the collapse prevention (CP) performance level on the 100-year earthquake map. The results of the FEMA 356 condition one analysis show that the strength ratio (μstrength) value of less than μmax has been met for 250-year and 1000-year earthquake maps with a review of the x and y directions of the earthquake. The value of the R ductility in 250-year and 1000-year earthquakes is above seven according to the earthquake force holding system of special reinforced concrete sliding walls. [ABSTRACT FROM AUTHOR]

Reinforced concrete (RC) columns with short lap splices built in the early 1970s or before are known to have deficient seismic strength and ductility. These short lap splices are poorly confined and located right above the foundation level, where it is known that the inelastic demands are high under seismic loading. In this study, a numerical model for estimating the lateral strength and deformation of RC columns with short lap splices is introduced. The latter model is based on local bond–slip analytical models derived from isolated anchored bars through the closed-form solution of the differential equation of bond. The proposed model is correlated to experimental data from cyclic loading tests on RC columns with deficient lap splices. It can be seen that the strength of short lap splices, the failure mode, and the column's lateral resistance and deformation are in good agreement with the experimental results both under monotonic and cyclic seismic analyses. [ABSTRACT FROM AUTHOR]

Copyright of Romanian Journal of Materials / Revista Romana de Materiale is the property of Foundation for Materials Science & Engineering Serban Solacolu and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In recent decades, non-wood lignocellulosic materials have gained significant attention, particularly in concrete applications for construction purposes. This study delves into utilising non-wood lignocellulosic materials for reinforcing concrete in construction applications. Lignocellulosic material emerges as a promising option for formulating new fibre cement compositions, thereby enhancing the sustainability, affordability, and performance of construction materials. Moreover, this research broadens the horizons of recycling agricultural waste by facilitating rational disposal and optimal utilisation. Through a comprehensive review, the study reveals that flax fibres, coir pith, prickly pear fibres, and rice husk ash waste exhibit superior workability compared to their counterparts. Furthermore, the strength of non-wood lignocellulosic reinforced concrete, incorporating bagasse ash, rice husk ash, and nutshell ash, peaked when fine aggregate replacement reached 15%, surpassing other types of non-wood lignocellulosic reinforced concrete. Adding a small quantity of prickly pear fibre to cement enhances the thermal conductivity of concrete, consequently improving compressive strength, flexural strength, tensile strength, and elastic modulus. This research is relevant to international research as it advances sustainable construction materials with desirable properties, benefiting society and various industries. [ABSTRACT FROM AUTHOR]

In the field of Reinforced Concrete Construction, concrete emerges as the predominant and extensively employed construction material. Concrete comprises a solid, chemically inert granular substance called coarse aggregate (CA) bonded with cement and water. Compared to fine aggregate or cement, CA has a larger volume of concrete. By examining the characteristics of the coarse aggregate using various laboratory testing processes, the coarse aggregate may be properly used in concrete. Bangladesh is experiencing significant growth in its infrastructure industry due to the construction of mega projects nationwide. For the building of RCC in Bangladesh, coarse aggregate is mainly procured from two sources in Bangladesh, and another is imported from China. This study aims to develop a clear understanding of aggregate and concrete strength quality for different coarse aggregates and track changes in the appearance of CA from multiple sources in China and Bangladesh. Coarse aggregates were collected from four prominent sources: Jaflong and Bholaganj (Bangladesh), Shandong, and Jiangsu (China). ACV (aggregate crushing value), gradation, voids, and unit weight; AIV (aggregate impact value), absorption, specific gravity, and resistance to abrasion-induced deterioration; and Los Angeles (LA) machines’ impact tests have been conducted for all sources of CA. The concrete cylinder was made and tested for all sources of CA with the same ratio of cement, sand, and water to know the concrete strength for different CAs. [ABSTRACT FROM AUTHOR]

This study investigates recent incidents of slabs collapse in reinforced concrete T-beam constructions attributed to deficiencies in design detailing and execution. It employs numerical analyses using the finite element method in ANSYS software to model T-section beams, with validation against experimental tests. Subsequently, a parametric study is conducted to explore the behavior of T-section beams under various design and construction variables, including the spacing of secondary reinforcements in the slab, the diameter of secondary main reinforcements, and slab thickness. The numerical analysis results are found to align well with experimental findings. The parametric study highlights that the eccentricity of reinforcing bars in the secondary direction of the slab is more detrimental than in the main direction. Furthermore, using 10 mm diameter reinforcement in the slab, either in the main or secondary direction, enhances the slab's resistance to applied loads. Additionally, the study reveals that increasing the stiffness of the slab contributes to an improved resistance of the beam. [ABSTRACT FROM AUTHOR]

Factors, which cause fracture of reinforced concrete constructions of bridge structures were considered. One of them is anti-icing material used for road safety in the winter period. The Ukrainian market of anti-icing chemical reagents and combined agents of natural and industrial origin was analyzed. The kinetics of corrosion fracture of 09G2S and St3 steels as the main material of reinforcement in neutral chloride-containing and alkaline solutions was investigated using the method of polarization resistance. Taking into account the kinetics of corrosion fracture of the studied steels, the rate of their general corrosion was calculated. [ABSTRACT FROM AUTHOR]

Prefabrication of reinforced concrete during the First and Second World Wars – the work of Benno Löser between the TH Dresden and Auschwitz The book on "Design methods for concrete and reinforced concrete components" shaped practical reinforced concrete construction like no other, and not just in Germany. However, little is known about its author, the building contractor and university professor Benno Löser (1878–1944). Early on, he dealt with questions about prefabrication and assembly logistics in concrete construction, and a large number of the buildings he constructed are now architectural monuments with a pioneering constructive character. This also applies to his work during the First and Second World War, where he focused on the topic of prefabrication of prefabricated concrete parts for various instances and ultimately became entangled in the unjust National Socialist state. He also used his professional expertise in places of destruction, such as Auschwitz and Dyhernfurth. The first research results from the current research project on the history of composite materials in construction by the Chair for the History of Natural Sciences and Technology at the University of Stuttgart are presented here. Based on previously completely unknown image and written documents from the estate of Benno Löser, who commuted between university operations and the practical challenges of construction, an insight into prefabricated reinforced concrete construction during two world wars is provided. [ABSTRACT FROM AUTHOR]

On the 200 th birthday of Gustav Robert Kirchhoff: The plate theory was finalised 175 years ago Gustav Robert Kirchhoff (1824–1887) is remembered for five important achievements in 19th century physics: – Circuit laws (Kirchhoff's current and voltage law), 1845 – Theory of the thin, elastic plate, 1850 – Theory of the thin, elastic rod with large deformations, 1859 – Foundation of spectroscopy with Robert W. Bunsen (1811–1899), 1859 – Law of thermal radiation, 1859 There is also the Piola‐Kirchhoff stress tensor from continuum mechanics. This list of Kirchhoff's impact on physics could be continued. In addition to the biography, the following focuses on the genesis of the theory of the thin, elastic plate, which is important for reinforced concrete construction. [ABSTRACT FROM AUTHOR]

Aare Bridge, Aarau (CH) A new bridge over the Aare was inaugurated in 2023 at a site where bridge structures have stood since Roman times. It connects the north bank with the old town of Aarau, the capital of the canton of Aargau, to the south. The new Aare bridge combines a modern interpretation of traditional aesthetics with functionality and efficiency. With a length of approx. 119 m, a width of 17.5 m, a main span of 44 m and two secondary spans of approx. 29 m, it has two lanes, sidewalks on both sides and bicycle lanes. The rational reinforced concrete construction is economical in its use of materials thanks to its thinned‐out geometry and hollow bodies. The bridge rests partly on the two caissons of the old bridge, which was built in 1949. The bridge structure is visually extended at its 4 extremities in the foreland by retaining walls, the lengths of which vary between 45 m and 89 m. The appearance of the bridge is inspired by the massive stone walls in Aarau. The light coloring of the concrete supports the dialogue with the surroundings. Where the bridge spans the riverside path, large openings offer a view across the water. On the side of the old town, there is an urban promenade with trees and, on the northern bank, green flower meadow areas and natural riverbank vegetation. [ABSTRACT FROM AUTHOR]

This paper aims to identify the optimal reinforced concrete bridge construction for regions at risk of mining-induced seismic shocks. This study compares the performances of two common bridge types made of the same structural tissue, i.e., a reinforced concrete beam bridge and rigid-frame bridge under real mining-induced tremors using uniform and spatially varying ground motion models. This study investigates the dynamic responses of the bridges depending on wave velocity and assesses their susceptibility to mining-triggered tremors based on the contribution of quasi-static and dynamic effects in the global dynamic responses of the bridges. This study revealed significant changes in dynamic response under spatially varying ground excitation for both bridge types. It was observed that rigid-frame bridges show higher susceptibility to quasi-static effects due to their stiffness, whereas beam bridges are more susceptible to dynamic stresses. This study recommends that in regions with mining tremors, the choice between bridge types should consider the possibility of limiting individual components of stress. A solution may involve the reduction in quasi-static components through structural reinforcement or decreasing dynamic components by using vibration absorbers. It was found that beam bridges are more cost-effective and practical in mining-affected areas, especially when founded on weak grounds. [ABSTRACT FROM AUTHOR]

Copyright of International Journal of Engineering Research & Development (IJERAD) is the property of International Journal of Engineering Research & Development and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of ABE: Advances in Building Education is the property of Departamento de Tecnologia de la Edificacion, Universidad Politecnica de Madrid and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this paper, we address the relatively underexplored topic of the bond behavior between various carbon rebars and high-strength concrete. This research aims to bridge the knowledge gap in understanding how different manufacturing processes and surface profiles of carbon fiber rods influence their bond strength with concrete. Through experimental bond tests comparing different carbon fiber rebars with varied surface profiles and manufacturing methods, we observed that the achievable bond stresses are significantly influenced by these factors. One carbon rebar variant was selected based on preliminary investigations for detailed analysis. Extensive investigations were conducted on the preferred carbon rebar. Factors such as concrete strength, bond length, and testing speed were experimentally explored. The results not only corroborate many findings from traditional reinforced concrete construction but also reveal new phenomena unique to carbon rebars. These insights are crucial for advancing the application of carbon rebars in modern construction, offering a potential solution to challenges faced in conventional concrete construction. [ABSTRACT FROM AUTHOR]

The addition or substitution of various gel materials in cement-based composites has been proven to be an effective approach in enhancing the performance of concrete. Current research focuses mainly on enhancing the toughness of concrete, but lacks discussion on the performance of alternative gel materials. Therefore, this study aims to explore the effects of partially substituting cement with fly ash and slag powder as gel materials, while incorporating a high volume fraction of micro-steel fibers (6%), on the workability and mechanical properties of self-compacting concrete. By means of rigorous experimental investigation and meticulous analysis, we comprehensively assessed the workability characteristics of self-compacting concrete, encompassing critical aspects such as filling ability, cohesion, and permeability. Additionally, we conducted an extensive evaluation of the mechanical attributes of self-compacting concrete, encompassing vital parameters, such as compressive strength, axial compressive strength, splitting tensile strength, and flexural strength. Last but not least, through a holistic integration of workability and mechanical properties, we conducted a comprehensive performance evaluation of self-compacting concrete incorporating a synergistic blend of fly ash, slag powder, and micro steel fibers. The experimental results indicate that the composite addition of fly ash and slag powder in self-compacting concrete, while compatible with up to 6% micro-steel fibers, leads to a decrease in concrete workability and an increase in cohesiveness due to the addition of micro-steel fibers. Moreover, fly ash predominantly influences the tensile properties of concrete, while the addition of slag powder significantly affects the compressive and flexural properties of concrete. Additionally, the addition of micro-steel fibers significantly improves the overall mechanical properties of concrete. [ABSTRACT FROM AUTHOR]

Recycling aged asphalt pavement has become increasingly important due to its environmental and economic advantages. Asphalt, serving as the binding agent for aggregates, plays a crucial role in pavement integrity. The deterioration of asphalt binder properties upon aging poses a significant challenge to asphalt pavement recycling. Consequently, various rejuvenators have been developed to restore aged asphalt binder properties and facilitate pavement reclamation. Waste cooking oil (WCO) is a widely used rejuvenator that mitigates the high viscosity and brittleness of aged asphalt, preventing cracking. WCO consists of triglycerides (TG) and free fatty acids (FFA), each with distinct molecular structures. In this study, molecular dynamics simulations were employed to investigate the individual effects of 10 wt.% TG and FFA on the viscosity, self-diffusion, and microstructure of aged asphalt at 1 atm and 404 K. The results demonstrate that both TG and FFA can reduce the viscosity of aged asphalt, albeit through different mechanisms. TG and FFA, characterized by high molecular mobility when dispersed in aged asphalt, enhance its mobility and reduce its viscosity. Additionally, TG effectively disrupts preferential interactions among asphaltenes, preventing their self-aggregation. In contrast, FFA has a limited impact on reducing these interactions. Furthermore, the study delves into the entanglement behaviors of FFA and TG with varying chain lengths within aged asphalt. Shorter chain lengths, as opposed to longer ones, exhibit a lower likelihood of entanglement with other asphalt molecules, resulting in increased molecular mobility and reduced asphalt viscosity. The fundamental insights gained from this research serve as a valuable reference for the application of waste cooking oil in the recycling of aged asphalt pavement. By shedding light on underlying molecular dynamics, this study contributes to the development of more effective and sustainable approaches to asphalt recycling. [ABSTRACT FROM AUTHOR]

Delayed ettringite formation (DEF) is a recognised durability issue in concretes where the temperature during curing has been elevated. To address the potential risk of DEF, Australian specifications for heat and steam cured concretes, such as TfNSW B80, MRTS 70, and MRS 820, restrict the maximum concrete temperature during heat or steam curing to 70 or 80 °C (depending on the jurisdiction). The wide range of road authority specifications in Australia has led to uncertainty among precast concrete manufacturers, designers, and contractors, as there is a lack of clarity on how less durable the concretes become when they breach these temperature limits. Moreover, the role of supplementary cementitious materials (SCMs) in mitigating DEF in the specifications is unclear. This paper addresses these concerns by reporting some of the outcomes from research carried out over the last 8 years at the University of Technology Sydney investigating the factors that raise the risk of deleterious DEF. The work indicates that the risk of DEF is low if the cements conform to Australian specifications (AS 3972 and ATIC-SP43). The risk is further reduced if fly ash (FA) is used as part of the binder composition. As the risk of DEF is low if a limit is placed on the alkali and sulphate contents in the cement and is further mitigated if FA is used to partially replace the cement, a more practical and standardised approach to heat cured concrete specifications across the Australian jurisdictions could be adopted. [ABSTRACT FROM AUTHOR]

The large-thickness concrete cover was detected by electromagnetic method and radar method, and the data were compared and analyzed with that obtained from direct method. The results indicate that the radar method is more accurate to detect the concrete cover, and it is used to detect the large -thickness concrete cover. The relative dielectric constant of concrete at different age was determined by making the calibration plate of concrete cover. The large-thickness concrete cover could be accurately detected by using the relative dielectric constant of concrete at 14 d age, which provide the basis for the optimization adjustment of steel binding construction and ensure the construction quality of reinforced concrete. [ABSTRACT FROM AUTHOR]

The houses financed through MIDUVI, as is the case of the T8 house, are designed for a family of only five members at most, that is, mother, father and three children; However, what happens as time goes by is that older children often have a partner and want to start a new home; which is a very recurrent situation in Latin American culture. With this background, it is essential to provide an alternative so that the T8-type house can have efficient vertical growth, through a second floor, which can be converted into a second home to accommodate the members of the extended family. Therefore, the primary objective of this document is "Determine the feasibility of progressive vertical growth in social housing - MIDUVI type T8 with traditional materials for the improvement of spatial conditions and habitability of users and the reduction of the environmental impact produced by conventional construction in the Portoviejo canton": for which the methodology used was of a mixed type, through a user survey and review of bibliographical bases. In the same way, an analysis of the essential materials for the proposed construction process was carried out, as well as the plans and their general details. From all this study it was obtained as a conclusion that the vast majority of respondents who determine outstanding benefits in construction with traditional materials such as cane and wood, such as comfort, sustainability and economy, which makes it a major socioeconomic constructive option. feasibility than conventional construction based on reinforced concrete. [ABSTRACT FROM AUTHOR]

This research focuses on the risk management of reinforced concrete heritage constructions in coastal environments, with an emphasis on preserving their cultural significance. It addresses a critical gap in existing risk-related research, since this type of heritage site is often overlooked in heritage conservation research. The proposed methodology offers a flexible framework that links natural and human-induced hazards with their impacts on key heritage values, enabling the development of appropriate mitigation and adaptation strategies and policies. Climate change-induced threats are also incorporated, allowing for more effective adaptation plans to safeguard concrete coastal heritage for future generations. The Ocean Swimming Pool in Matosinhos, Portugal, designed by the Pritzker Prize winner Álvaro Siza, serves as a pilot study to illustrate the practicality of the risk-based approach, considering its coastal location and exposure to various hazards. By using this case study, the research provides a roadmap for preserving and adapting heritage constructions in similar coastal settings. The integration of cultural values into risk management and conservation policies is a significant contribution of this research. It advocates for a proactive approach that considers the dynamic challenges posed by climate change while preserving the significance of cultural heritage. The adaptable nature of the proposed methodology allows for broader applications, potentially benefiting multiple heritage sites in coastal regions. Ultimately, this research calls for positive changes in risk management practices to ensure the preservation and longevity of culturally significant reinforced concrete heritage sites. [ABSTRACT FROM AUTHOR]

Precast reinforced concrete constructions meet the requirements of industrialization, high manufacturability, and cost-effectiveness at a reasonably high level. The ribs in constructions perform load-bearing functions, and the slab part performs enclosing functions. Often before the installation of such structures at a construction site, they are mounted from assembly elements. The overall dimensions of the elements are limited by transportation requirements. During such an aggregated mounting, the assembly units work according to a calculation scheme that differs from an operational scheme. The structural nonlinearity of ribbed reinforced concrete slabs during transportation, mounting, and installation, and the operation of a combined spatial covering panel were investigated in this paper. The effects were identified, and a rational design of nodes connecting the individual prefabricated units into a spatial structure was developed. With the help of these nodes, it is possible to create unloading support moments, which will reduce the internal forces in the design cross-sections. The effects of changes in the width of the reinforced concrete slab shelves on the internal forces of the load-bearing ribs of a wall and a roof panel were investigated. [ABSTRACT FROM AUTHOR]

Reinforced concrete corbels were examined in this study for the cracking behavior and strength evaluation, focusing on defects typically found in these structures. A total of 11 corbel specimens were tested, including healthy specimens (HS), specimens with lower concrete strength (LC), specimens with less reinforcement ratio (LR), and specimens with more concrete cover than specifications (MC). The HS specimens were designed using the ACI conventional method. The specimens were tested under static loading conditions, and the actual strengths along with the crack patterns were determined. In the experimental tests, the shear capacity of the HS specimens was 28.18% and 57.95% higher than the LR and LC specimens, respectively. Similarly, the moment capacity of the HS specimens was 25% and 57.52% greater than the LR and LC specimens, respectively. However, in the case of the built-up sections, the shear capacity of the HS specimens was 9.91% and 37.51% higher than the LR and LC specimens, respectively. Likewise, the moment capacity of the HS specimens was 39.91% and 14.30% higher than the LR and LC specimens, respectively. Moreover, a detailed nonlinear finite element model (FEM) was developed using ABAQUS, and a more user-friendly strut and tie model (STM) was investigated toward its suitability to assess the strengths of the corbels with construction defects. The results from FEM and STM were compared. It was found that the FEM results were in close agreement with their experimental counterparts. [ABSTRACT FROM AUTHOR]

After being processed into a certain shape by a stirrup bending machine, steel bars are used as the skeleton of reinforced concrete in construction. The accuracy of their bending directly affects the bearing capacity of reinforced concrete. In order to improve the accuracy of the springback angle of steel bars after bending, this paper focuses on optimizing the structural parameters of the steel bar bending machine and controlling the springback angle of steel bars. The influence of the support shaft diameter, bending crankshaft diameter, and bending crankshaft radius on the springback angle of steel bars is analyzed using ANSYS explicit dynamic simulation and experimental analysis. By combining orthogonal experimental methods, the bending structural parameters were optimized, including a support shaft diameter of 20 mm, a crankshaft bending diameter of 40 mm, and a crankshaft bending radius of 80 mm. This can effectively reduce the springback angle of the steel bars and improve the accuracy of the bending angle after bending. In addition, in order to improve the control accuracy of the steel bar springback angle, a cubic spline interpolation method was proposed, and the collected steel bar springback angle data were fitted using Matlab. At the same time, comparisons were made between the least squares method, polynomial interpolation method, and cubic spline interpolation method. The results show that the compensation formula obtained by using the cubic spline interpolation method can effectively improve the control accuracy of the steel bar bending springback angle. [ABSTRACT FROM AUTHOR]

High‐performance fibre reinforced concrete represents a promising alternative to conventional reinforced concrete for the construction of prestressed precast girders for road bridges. Specifically, all shear reinforcement is replaced by the use of steel fibres, which leads to important savings from the material and economical perspectives. Therefore, reliable shear formulations are required for these specific cases. In an effort to evaluate the accuracy of code expressions, this paper presents a database collecting 80 experimental shear tests on prestressed fibre reinforced concrete beams without stirrups. After illustrating its main characteristics, this database is used to verify the conservativeness and accuracy of shear formulation according to several codes and recommendations: i) Model Code 2010, ii) draft version of Model Code 2020, iii) draft version of the new Eurocode 2, and iv) Spanish National Code. The evaluation, carried out through the calculation of the model safety factor, indicated that the application of all shear formulations is largely conservative, leading to less unsafe tests than the desired 5% fractile. The relation between model safety factors and mechanical parameters is then investigated. Finally, the results obtained for the developed database are compared with those achieved from two larger databases of beams with similar features but without prestress. The comparison clearly proves the greater conservatism of code expressions when beams are prestressed. [ABSTRACT FROM AUTHOR]

Memorandum: corrosion protection in structural engineering One of the most important materials in structural engineering is steel in the form of structural steel, reinforcing steel, fasteners etc. Steel offers high strength in combination with any formability, good workability and weldability. In order to exploit the potential of steel, knowledge of its main damage mechanism – corrosion – is essential to prevent corrosion processes through consistent planning, constant corrosion condition assessment and, if needed, corrosion repair measures. The aim of this memorandum for higher education is to offer, discuss and further develop the foundations of competence development in the field of corrosion protection in structural engineering. Due to the increasingly dynamic developments in civil engineering (e. g. through digitalization, sustainability requirements, new production methods, longer service lives of structures), the willingness to constantly reflect and further develop is indispensable to ensure high quality in the corrosion protection of engineering structures in the long term. This memorandum is the result of the cooperation with the working group "Corrosion Protection in Structural Engineering" of the Gesellschaft für Korrosionsschutz e. V. (GfKORR) and bauforumstahl e. V. [ABSTRACT FROM AUTHOR]