bluuebunny/crossref_metadata_2025 huggingface dataset:
Weekend Admission Increases Risk of Readmissions Following Elective Cervical Spinal Fusion
Authors: Ren Renee , Dominy Calista , Bueno Brian , Pasik Sara , Markowitz Jonathan , Yeshoua Brandon , Cho Brian , Arvind Varun , Valliani Aly A. , Kim Jun , Cho Samuel
Published: March 2023

Objective: The “weekend effect” occurs when patients cared for during weekends versus weekdays experience worse outcomes. But reasons for this effect are unclear, especially amongst patients undergoing elective cervical spinal fusion (ECSF). Our aim was to analyze whether index weekend admission affects 30- and 90-day readmission rates post-ECSF.Methods: All ECSF patients > 18 years were retrospectively identified from the 2016–2018 Healthcare Cost and Utilization Project Nationwide Readmissions Database (NRD), using unique patient linkage codes and International Classification of Diseases, Tenth Revision codes. Patient demographics, comorbidities, and outcomes were analyzed. Univariate logistic regression analyzed primary outcomes of 30- and 90-day readmission rates in weekday or weekend groups. Multivariate regression determined the impact of complications on readmission rates.Results: Compared to the weekday group (n = 125,590), the weekend group (n = 1,026) held a higher percentage of Medicare/Medicaid insurance, incurred higher costs, had longer length of stay, and fewer routine home discharge (all p < 0.001). There was no difference in comorbidity burden between weekend versus weekday admissions, as measured by the Elixhauser Comorbidity Index (p = 0.527). Weekend admissions had higher 30-day (4.30% vs. 7.60%, p < 0.001) and 90-day (7.80% vs. 16.10%, p < 0.001) readmission rates, even after adjusting for sex, age, insurance status, and comorbidities. All-cause complication rates were higher for weekend admissions (8.62% vs. 12.7%, p < 0.001), specifically deep vein thrombosis, infection, neurological conditions, and pulmonary embolism.Conclusion: Index weekend admission increases 30- and 90-day readmission rates after ECSF. In patients undergoing ECSF on weekends, postoperative care for patients at risk for specific complications will allow for improved outcomes and health care utilization.
Pediatric Spinal Hemangioblastomas: Clinical Features and Surgical Outcomes of 39 Cases
Authors: Han Bo , Zhang Liang , Jia Wenqing
Published: March 2023

Objective: Spinal hemangioblastomas (HBs) are a rare pathology, especially in the pediatric population. The natural history and long-term outcomes of pediatric patients with spinal HBs remain unclear due to their scarcity.Methods: A retrospective review of the clinical data and treatment outcomes of children with spinal HBs in our institution from 2012 to 2021 was conducted.Results: Thirty-nine pediatric patients were included, with an average age of 15.9 ± 2.9 years (range, 8–18 years), and 51.3% were female. Children were more likely to have von Hippel-Lindau (VHL) disease (p < 0.001), a family history of VHL (p < 0.001), multiple symptoms (p = 0.006), a shorter duration of symptoms (p < 0.001), and a larger lesion size (p = 0.004) and volume (p = 0.008) than their adult counterparts. The VHL-associated group of patients was more likely to present with multiple symptoms (p = 0.026), have a family history of VHL (p < 0.001), have multiple HBs (p < 0.001) and have synchronous intracranial lesions (p < 0.001) than the sporadic group. After surgery, 15 patients (38.5%) showed improved clinical outcomes, 17 patients (43.6%) remained unchanged, 4 patients (10.2%) worsened, and 3 patients (7.7%) died of tumor progression. During follow-up, there was a high rate of recurrence and repeated surgery, especially for children in the VHL-associated group.Conclusion: Pediatric patients with spinal HBs appear to have a higher relapse risk than their adult counterparts. Therefore, life-long follow-up of these patients is necessary, especially for VHL-associated cases. Surgery can benefit children with HBs and should be considered early to avoid irreversible neurological deterioration.
Activating Endogenous Neurogenesis for Spinal Cord Injury Repair: Recent Advances and Future Prospects
Authors: Yu Haiyang , Yang Shangbin , Li Haotao , Wu Rongjie , Lai Biqin , Zheng Qiujian
Published: March 2023

After spinal cord injury (SCI), endogenous neural stem cells are activated and migrate to the injury site where they differentiate into astrocytes, but they rarely differentiate into neurons. It is difficult for brain-derived information to be transmitted through the injury site after SCI because of the lack of neurons that can relay neural information through the injury site, and the functional recovery of adult mammals is difficult to achieve. The development of bioactive materials, tissue engineering, stem cell therapy, and physiotherapy has provided new strategies for the treatment of SCI and shown broad application prospects, such as promoting endogenous neurogenesis after SCI. In this review, we focus on novel approaches including tissue engineering, stem cell technology, and physiotherapy to promote endogenous neurogenesis and their therapeutic effects on SCI. Moreover, we explore the mechanisms and challenges of endogenous neurogenesis for the repair of SCI.
Complications and Management of Endoscopic Spinal Surgery
Authors: Ju Chang Il , Lee Seung Myung
Published: March 2023

In the past, the use of endoscopic spine surgery was limited to intervertebral discectomy; however, it has recently become possible to treat various spinal degenerative diseases, such as spinal stenosis and foraminal stenosis, and the treatment range has also expanded from the lumbar spine to the cervical and thoracic regions. However, as endoscopic spine surgery develops and its indications widen, more diverse and advanced surgical techniques are being introduced, and the complications of endoscopic spine surgery are also increasing accordingly. We searched the PubMed/MEDLINE databases to identify articles on endoscopic spinal surgery, and key words were set as “endoscopic spinal surgery,” “endoscopic cervical foramoinotomy,” “PECD,” “percutaneous transforaminal discectomy,” “percutaneous endoscopic interlaminar discectomy,” “PELD,” “PETD,” “PEID,” “YESS” and “TESSYS.” We analyzed the evidence level and classified the prescribed complications according to the literature. Endoscopic lumbar surgery was divided into full endoscopic interlaminar and transforaminal approaches and a unilateral biportal approach. We performed a comprehensive review of available literature on complications of endoscopic spinal surgery. This study particularly focused on the prevention of complications. Regardless of the surgical methods, the most common complications related to endoscopic spinal surgery include dural tears and perioperative hematoma. transient dysesthesia, nerve root injury and recurrence. However, Endoscopic spinal surgery, including full endoscopic transforaminal and interlaminar and unilateral biportal approaches, is a safe and effective a treatment for lumbar as well as cervical and thoracic spinal diseases such as disc herniation, lumbar spinal stenosis, foraminal stenosis and recurrent disc herniation.
ON STRENGTHENING CRIMINAL LIABILITY FOR SEXUAL CRIMES COMMITTED BY CLOSE VICTIMS
Authors: Tydykovа N.V.
Published: March 2023

The article is devoted to the study of the question of the possibility of the influence of the nature of therelationship between the perpetrator and the victim on the differentiation of criminal liability for sexualcrimes. With references to foreign experience, it is proved that the commission of such crimes by personswho are in a relationship with the victims, involving trust, recognition of authority, security assurance, is afactor that significantly increases the degree of public danger of these crimes. It is proposed to supplementarticles 131, 132, 134 and 135 of the Criminal Code of the Russian Federation with such a qualifyingcircumstance as their commission by a person who is close to the victim, or lives together with the victim,or who is responsible for treatment, education or training. The substantiation of the differences betweenthe wording proposed for the Russian Criminal Code of the Russian Federation and those used by foreignlegislators is given. In each of the elements of crimes, the place of this qualifying feature is determined. It isproved that taking into account in such cases only the aggravating circumstance in the Criminal Code of theRussian Federation will not ensure an increase in liability to the required level.
Large Anorectal Venous Malformation Treated With Microfoam Therapy
Authors: Jha Ashish Kumar , Suchismita Arya , Dayal Vishwa Mohan
Published: March 2023

Deficiency of smooth muscle cells can lead to dysfunction and engorgement of blood vessels termed as hemangioma, arteriovenous malformations, and venous malformations (VMs). Anorectal VM is a rare disease. It can present with massive hematochezia. An optimal treatment of anorectal VMs has not been defined. Surgery is an option if the lesion can be resected completely. Endoscopic injection sclerotherapy has been reported to be effective in treating small colorectal VMs. However, it has rarely been described in the treatment of large VMs. In this study, we describe a rare case of large anorectal VMs treated with microfoam sclerotherapy.
Investigating critical thinking in higher education in Latin America: Acknowledging an epistemic disjuncture
Authors:   Universidad de Tarapaca, Guzmán-Valenzuela Carolina , Chiappa Roxana , Rojas-Murphy Tagle Andrés , Ismail Nagwa , Pedraja Rejas Liliana
Published: March 2023

Critical thinking (CT) in higher education (HE) has been widely investigated in Western countries. Most of the research on CT has conceived it as a higher order thinking skill with implications for learning processes. CT has also been connected with critical pedagogies, an approach that seems particularly attuned with the Latin American region. Through a systematic literature review, this article maps the scholarship on CT in HE in Latin America (LATAM). Findings point to a local character of the research on CT that heavily relies on cognitive psychology traditions. It is proposed that the scholarship on CT in LATAM is characterised by an epistemic disjuncture that favours theories and methodologies produced in the Global North overshadowing well-recognised traditions of critical pedagogies in the region. We conclude that research on CT in the region is missing an opportunity to develop powerful features that are especially fitting for LATAM’s geo-historic context.
Enacting criticality and care
Authors:   University of the Witwatersrand, Agherdien Najma
Published: March 2023

This article provides an account of one higher education teacher’s views on the notions of criticality and critique within the context of continuous professional learning spaces for academics and in which the Scholarship of Teaching and Learning (SoTL) is central. I present an account of enacting SoTL practices through criticality and (with) care. Included is an account of SoTL engagements with academics, a process that takes time, courage, patience, and hope. The argument that I make is that withholding critical care – which includes attentiveness, responsibility, competence, and responsiveness - is part of injustice. Hence, contestation, criticality, and critique with care must remain key SoTL activities. A twin argument is that (self) criticality is a precursor to critiquing others. The article concludes with implications of enacting criticality with care, in SoTL and beyond.
PREDICTION OF ABSORPTION RATE IN HOUSING PROJECT BY ARTIFICIAL NEURAL NETWORK
Authors: Pultawee Patcharida - , Tochaiwat Kongkoon -
Published: March 2023

When performing feasibility study and undertaking project design of housing projects, the absorption rate, e.g., the number of units sold per month, is one of the most important parameters to be predicted. However, the conventional prediction approach relies a lot on the knowledge and experience of the experts, which is various and rare. In this research, an Artificial Neural Network (ANN) was adopted for developing an absorption rate prediction model. The research was done by collecting the factors affecting the absorption rates of housing projects from literature review and from expert interviews. Then, the factors of 400 housing projects were collected and analyzed. The acquired model has two hidden layers with 10 and eight nodes, respectively. When testing with the new set of data, the model had R2 = 0.914. Real estate developers can use the acquired factors and model when making decisions to invest in new projects, as well as for finding the forms of projects that will lead to the required investment results. Keywords: Absorption Rate, Prediction Model, Housing Project, Artificial Neural Network.
THE EFFECT OF RE-CALCINATION FLY ASH ON GEOPOLYMER PERFORMANCE
Authors: Bari M Shahib Al , Ekaputri Januarti Jaya , Rasgianti Rasgianti , Anggarani Bernarded Oka , Wibowo Prasetyo Adi
Published: March 2023

Geopolymer is one of the concrete technologies to utilize fly ash from coal combustion residue. However, the unburnt carbon in fly ash deteriorates the mechanical properties. To reduce the carbon, the calcination is required. This study presents the effect of calcination at 1000 o C on five samples of fly ash. All fly ashes were activated with alkali activator having a mass ratio of Na2SiO3 to NaOH was kept constant at 2. Compression test was conducted at 3, 7, 14, 21, 28, and 56 days to obtain the effect of calcination to the compressive strength. It was found that the Si/Al ratio significantly affected the compression strength. The calcination reduced the carbon content in fly ash. However, amorphous phase of fly ash dropped after calcination as all the compression test result were less than 1 MPa. the calcination hindered the geopolymerization as all of the setting time exceeded seven days causing no compressive strength at early age.
REFRACTORY PROPERTIES OF CONCRETE USING SINGLE MICRON FLY ASH AND GROUND GRANULATED BLAST FURNACE SLAG FINE POWDER
Authors: Kuroki Chisato
Published: March 2023

In Japan, high strength concrete over 100 N/mm2 is generally used for high-rise buildings. In order to achieve a high strength of 100 N/mm2 or more, silica fume is used as an admixture. However, concrete using silica fume, when a fire occurs, concrete explodes, and the fire resistance performance deteriorates. Therefore, fibers such as polypropylene is used to improve fire resistance. But, since silica fume and fiber are expensive in Japan, there is a problem that the cost of concrete becomes high. Therefore, the authors examined the possibility of giving high strength and fire resistance to concrete by adding fly ash or blast furnace slag those are ground to the single micron region. In this study, fly ash and blast furnace slag with different particle sizes of 50% cumulative volume passage diameter of about 1 ~ 3 μm were used. In the experiment, fresh properties, compressive strength, and fire resistance of concrete were evaluated comparing to those of concrete using silica fume. As a result, for single micron fly ash, the larger the particle size is used, the better the fire resistance. Concrete using blast furnace slag showed no explosion at all levels. From the above, it was found that high strength concrete with refractory properties can be realized by using single micron fly ash and blast furnace slag fine powder.
ASSESSING THE ADAPTIVE REUSE OF HERITAGE
Authors: MAZZETTO SILVIA
Published: March 2023

In the last decades, due to oil discovery, many Middle East countries have experienced rapid urban growth and accelerated infrastructure and transport developments. A lively debate is currently investigating the directions for the new urban and architectural growth. The construction of contemporary cities characterized by innovation and technologies is in contrast with the need to preserve and rehabilitate the national heritage by establishing new links with local history and culture. The paper presents some significant examples of recently completed adaptive reuse projects in the Middle East area and shows the growing need to strengthen local heritage value. The interventions were assessed by considering the environmental, socio-economic, and socio-cultural aspects derived from the adaptive reuse project. As a cultural, social, environmental, and energy-saving value, sustainability is one of the most important principles that should be applied to any restorative intervention on heritage. The assessment results show that there are many links between heritage restoration, promotion of cultural values, synergy with climate, and the compatible adaptive reuse of the restored buildings. Therefore, the concept of sustainability is addressed through its meaning of unity and harmony in a broad sense by considering the respect for the ecosystem, social aspects, investments, and costs, which may vary depending on the scale of interventions ( urban-architectural). The aim is to define a persistent approach to restoration while respecting the environmental principles of sustainability.
THE PHYSICAL MODEL FOR THE IL PAVILION AND THE USAGE OF ITS DIGITAL TWIN
Authors: wenzel baris , Schmid Benjamin , Möller Eberhard , Nett Julia , Weber Christiane
Published: March 2023

The so-called IL pavilion in Stuttgart, constructed by Frei Otto and the Institute for Lightweight Structures (IL) served itself as an experimental building for testing the execution of a new type of cable net construction. At this 1:1 mock-up various manufacturing techniques and measuring methods were tested, additionally to model tests on physical models. These models were necessary, because at that time no adequate calculation methods were available to design the complex geometries of such wide-span cable net constructions. In this paper, the authors clarify the way the model was produced, the development of the measurement methods and the impact of model testing for the execution of the innovative construction of the German pavilion for the World's Fair in Montréal in 1967. The physical model, which is one of the few surviving measurement models from this period, was digitally rebuilt with state of the arts methods in the context of the DFG research project “last witnesses”. The data extracted from the physical model was compared with a model generated from the original cut stencils. Overall, the numbers match fairly well, nevertheless there are some outliers due to the changed numbers of elements, which have a deviation of more than 40%. The data extracted from the digital twin will further be used to evaluate changed boundary conditions, increased snow loads or wind effects for the building itself and to record the actual state of the model for future preservation measures.
INVESTIGATING THE IMPACT OF BIO-INSPIRED FAÇADE DESIGN ON INDOOR ENVIRONMENT
Authors: SHASHWAT SHASHWAT , ZINGRE KISHOR , THURAIRAJAH NIRAJ
Published: March 2023

Bio-inspiration is a growing research field in architecture and urban design where this framework is being used to design and develop sustainable solutions and strategies for improving the overall built environment. In buildings, the façade is the most critical element which differentiates the indoor environment from the outdoor environment. The research related to the quantification of the impact of bio-inspired façade on the indoor environment is limited. This research, therefore, aims to evaluate the impact of three-dimensional retro-reflective design on the building facade. The retro-reflective design can functionally perform to reflect off the incident solar radiation along with providing an aesthetical appeal. The research has been conducted on a (2-storey) typical residential building in the United Kingdom using computational simulation. Test building with bio-inspired façade i.e., retro-reflective design is developed in SketchUp and simulated using OpenStudio and EnergyPlus software. The results were compared against the baseline model with similar dimensions (without the bio-inspired design). The surface inside face temperatures and zone air temperatures are analysed to investigate the impact on the indoor environment. The result shows that the bio-inspired façade design reduces the façade internal surface temperature by up to 3.7°C and zone air temperature by up to 1.9°C under UK’s weather conditions during summer.
PRESERVATION OF RAMMED EARTH STRUCTURES THROUGH TRADITIONAL METHODS: CASE STUDY
Authors: Pellicer Teresa María , Lopez-Mateu Vicente
Published: March 2023

This paper describes the research carried out around a high heritage value construction, the Torre Muza de Benifaió in Valencia (Spain). The tower is a defensive building from the Spanish Arab period, built during the 11th and 12th centuries AD. When the studies began, it was abandoned, in a dilapidated state, and slight information was known. Therefore, following extensive and multidisciplinary work was the starting point to recognizing the critical aspects of its history, damage, and current condition. Particularly noteworthy is the specific characterization of the traditional rammed earth construction system and the materials that made it up. All this was performed based on historical research, laser 3D scanning, and complementary characterization studies (physical, chemical, and mechanical) with the vision of the whole and surroundings. With all this, it was possible to determine the recovery of the walls following the same construction technique, although differentiating their specific execution. These preliminary studies allow a respectful consolidation and recovery of the construction and ensure the compatibility and integration of the materials and the intervention. This paper remarks on the importance of multidisciplinary preliminary studies to develop proper preservation of vernacular techniques and heritage architecture.
GREEN WALLS CAN IMPROVE INDOOR AIR QUALITY IN THE CLASSROOM
Authors: Taemthong Wannawit , Cheycharoen Navapa
Published: March 2023

Buildings are places where people live and perform daily activities. Good indoor air quality is essential for them to live healthily inside. In order to provide satisfactory indoor air quality, a green wall should be installed to reduce indoor carbon dioxide (CO2). Several research studies have been conducted examining the effects of indoor CO2 levels. However, this research emphasizes studying the impact of light sensitivity on the ability of plants to reduce CO2. Four types of ornamental plants constituted our sample, Nephrolepis exaltata, Chlorophytum comosum, Epipremnum aureum (Marble Queen), and Epipremnum aureum (Spotted Betel). The plants were placed in an experimental box to allow us to investigate their ability to reduce CO2 over a 24-hour period. The most effective plant was then tested on a green wall in a classroom enabling the study of CO2 reduction in three different locations with varying light levels. It was found that green walls with Marble Queen placed perpendicular to windows allowing optimum light exposure were able to reduce CO2 at the most favorable rate of 1.74 ppm/min.
IMPLEMENTATION OF PROJECT BUNDLING
Authors: D'Angelo Daniel , Minchin Edward
Published: March 2023

Project bundling (PB) is a process through which transportation agencies use a single contract award to contract for the construction of multiple bridges or roadways. Users aim to combine multiple projects into a single contract for continued development. The practice began to gain wide acceptance in the U.S. about five years ago; and, with the support of the Federal Highway Administration (FHWA) Every Day Counts initiative, more and more agencies are now considering and applying PB. As its use increases, agencies are developing statutes, rules, procedures, and guidelines for implementation. The FHWA formed a technical working group (TWG) to support the wider application of PB, and both authors are members of this group—the lead author acting as TWG Chair, and the second author as a TWG member. This paper explores the FHWA works to popularize a contracting process that shows great potential. It also provides a compelling case study of one its early successes.
PROJECT MANAGER'S LEADERSHIP STYLES AFFECTING CONSTRUCTION PRODUCTIVITY
Authors: Robbertse Catherine , Amoah Christopher
Published: March 2023

Productivity in the construction industry is essential for business sustenance. Project Managers play a significant in achieving productivity in construction. Therefore this study examined the critical project manager's leadership style to influence construction productivity. The study adopted a quantitative research approach; thus, closed-ended questionnaires were distributed to construction professionals via the Survey Monkey platform. Data gathered were analyzed using descriptive statistics to identify frequencies and weighted scores. The findings indicate the main factors affecting construction productivity as incompetent supervising and management, poor leadership, lack of skilled and experienced labour, and poor project communication. Therefore project managers should exhibit supportive (ability to delegate and assign tasks to the employees), charismatic (ability to transform attitudes and beliefs in employees), transformational (ability to inspire others), and democratic (ability to include employees in decision making) leadership styles to influence construction productivity positively. There is an urgent need for project managers to be trained on the appropriate soft skills aspect of managing construction projects to effectively improve construction productivity, reduce project cost and time overruns, and sustain construction businesses.
INVESTIGATING THE INTERRELATION OF COST RISKS IN LARGE-SCALE PROJECTS WITH A SYSTEM DYNAMICS APPROACH
Authors: Rokooei Saeed , Yousefzadeh Fatemeh
Published: March 2023

Large-scale projects are considered the riskiest projects due to their multidisciplinary nature and complexity. The main risk factors include a high project budget, technical challenges during project implementation that did not exist before, continuous project change orders, and environmental factors governing them. On the other hand, the project manager sometimes cannot correctly manage project risks and solve problems by applying traditional approaches despite spending enormous resources. Limitations of traditional risk management methods based on separate consideration of the impact of each risk and not considering the interrelations of risks, causal relationships between them, and the dynamic behavior of risk factors during the project lead project managers to resort to new methods such as dynamic risk management and the interaction of risks. Therefore, considering the number and position of large-scale projects within Iran and their role in economic and technical development, the present study is essential. In this study, by presenting a classified list of risks of large-scale projects, risks interaction will be identified, and then using the obtained relationships, we will present a dynamic model with the interaction of all risk factors on each other.
A REVIEW OF PUBLIC-PRIVATE PARTNERSHIPS FOR RENEWABLE ENERGY PROJECTS IN DEVELOPING COUNTRIES
Authors: Othman Kareem , Khallaf Rana
Published: March 2023

The increasing need for energy worldwide to gain energy security along with the negative externalities of fossil fuel have motivated some countries to seek new sources of energy known as renewable energy. The main benefit of these renewable energy sources is their ability to provide clean, reliable, affordable, and sustainable energy to millions of people. On the other hand, renewable energy technologies require high up-front investment, which is problematic especially for developing countries. Therefore, public-private partnerships (PPPs) have become an attractive delivery method in order to take advantage of the technology, innovation, and capital of the private sector to support the public sector in providing their services. However, there is a dearth of information on the current pattern, obstacles, as well as the success factors of PPPs in renewable energy in developing countries. Thus, this study reviews previous renewable energy public-private partnership projects with the objective of developing a detailed understanding of renewable energy projects delivered through these PPPs in developing countries. Additionally, this study identifies the characteristics of the PPP projects and the lessons learned obtained from these PPP projects. This will aid in identifying the critical success factors needed for the successful implementation of renewable energy PPP projects in developing countries.
AN OVERVIEW OF MULTI-CRITERIA DECISION MAKING TECHNIQUES IN CONSTRUCTION PROJECTS CLAIMS MANAGEMENT
Authors: Matseke Dikeledi Anna , Khatleli Nthatisi , Root David
Published: March 2023

Claims in the construction sector result from, but not limited to, poor contract performance, delays, conflicts and force majeure. The use of Multi-Criteria Decision Making (MCDM) techniques are proposed in construction-related decision-making and prove advantageous in ensuring that claims management processes are effective. This paper provides an overview of existing MCDM techniques proposed for construction claims management. A narrative literature review is performed where Google Scholar and EBSCO host are used to identify relevant articles for the study and 49 articles were selected. From literature, some of the proposed techniques in construction claims management are AHP, ANN, NN, MAUT, SWOT, TOPSIS and VIKOR. Findings from the study indicate that the outdated nature of traditional standalone MCDM techniques has seen the use of hybridised models in construction-related decision-making more useful. Supplementing MCDM techniques with techniques such as BIM is rather relevant since BIM alone has the potential to reduce claims emerging from large construction projects.
EFFECT OF CURVATURE ON THE TENSILE STRENGTH OF FRCM
Authors: Messerer Dennis , Holschemacher Klaus
Published: March 2023

Fabric reinforced cementitious matrix (FRCM) systems are promising composite materials which are increasingly used for the strengthening of reinforced concrete components. The interaction of high performance, fine-grained concretes and noncorrosive, high strength textile reinforcements combines many advantages of shotcrete linings and externally bonded fiber-reinforced polymers (FRP). For this reason, especially the retrofitting of plane concrete structures with FRCM has already been investigated appropriately. However, the application of FRCM systems in edge regions and curved areas, such as the confinement of reinforced concrete columns or shear strengthening of beams, leads to a reduction of the systems' tensile strength. This reduction is mainly caused by additional transverse pressure, cracks in the concrete matrix, and possible pre-damage due to the bent textile. As most available prediction models use static reduction factors, the dependencies of these influences have not been considered sufficiently yet. This paper presents an experimental study regarding the effects of curvature on the tensile strength of FRCM-strengthening layers. Therefore, 93 specimens with varying radii, FRCM composite materials, and numbers of applied textile layers were tested in a newly developed setup. The test results show significant dependencies on the various parameters and contrast with the static reduction factors used so far.
EFFECT OF INCINERATED SUGARCANE BAGASSE IN REDUCING HEAT OF HYDRATION IN CONCRETE
Authors: Bizuneh Miheret Geremew , Ftwi Esayas Gebreyouhannes
Published: March 2023

Incinerated sugarcane bagasse (ISB) is an agro-based industrial waste material which is rich in silica. It has been observed that it has the potential to reduce the heat that will be generated from hydration reaction. Lower rate of heat release and lesser magnitude of heat production during the hydration reaction of cement are desirable properties in mass concreting and production of concrete in hot weather condition. In this study, the heat evolution and tensile strength development of concrete with and without the inclusion of ISB was examined. A systematic volume-based replacement of cement by ISB was made with ISB amount of 10%, 20% and 30%. The hydration kinetics of cement paste with various percentages of ISB was checked using differential calorimeter. In addition, a concrete made with ISB was prepared and the temperature evolution history was traced in an environmentally controlled chamber. The heat generated from a set of concrete samples were studied under a surrounding temperature of 250 C and 500 C. Results obtained from both the differential calorimeter of cement paste and the concrete in the controlled chamber indicate, with the increase of the ISB replacement, the rate of heat release and the amount of heat generation within the mix decreases. In conjunction, with the increase of ISB up to 20% the early-age tensile strength of concrete increases. These two important attributes of adding ISB to concrete signify reduction in the risk of early age cracking in concrete.
STATIC YIELD STRESS MEASUREMENTS OF FINE AGGREGATES
Authors: Hertwig Ludwig , Holschemacher Klaus , Mechtcherine Viktor
Published: March 2023

Fine grained concrete with a maximum grain size of D = 2 mm can be designed as high-performance concrete with outstanding properties. Typical applications are 3Dprinting, grouts, textile-reinforced concrete and thin high-performance structures. Studies reported in the literature that with decreasing grain size the impact of the granulometric properties of the aggregates is increasing. These properties are not only influencing the water demand but also the rheological behavior, such as the static yield stress. In order to investigate and quantify the effects of granulometry on static yield stress measurements six different sands of threedeposits within the range of d/D = 0/2 mm and industrial made glass spheres were tested. The granulometric properties of the materials have been investigated using digital image analyzing. The measurement device was a rotational viscosimeter (Viskomat NT) equipped with a Vane-paddle. Factors as the sample preparation (compaction) and applied shear rateunder a constant shear rate protocol (CSR) were analyzed. An optimum measurement procedure for the grain mixtures was found in using 0.2 rpm and a layerwise static compaction. The analysis showed the importance of the grain size distribution of comparable grain mixtures regarding the static yield torque.
SHEARING STRAIN OF SQUARE CROSS-SECTION SHAFT BY IMAGE ANALYSIS IN LARGE TORSION AFTER AXIAL LOAD
Authors: kato yasuyuki
Published: March 2023

This paper describes the characteristics of the distribution of shearing strain along the cross section when a large torsion after axial load is applied to a test specimen having a square cross section made of natural rubber. As for the measurement of finite strain under large deformation, a method based on image analysis, which can continuously measure a wide range from infinitesimal deformation to large deformation, is effective. Therefore, in the present study, a method by image analysis is adopted as measurement of shearing strain that occurs under large torsion. On taking image data, marking-off lines are preliminarily drawn on the surface by describing equally-spaced parallel lines vertically as well as horizontally, and images of horizontal elements along cross sections at upper position or center position of the test specimen are taken with high-resolution cameras with macro lens. The shearing strain distributions in the transverse section are measured by using the image analysis reflecting the Natural Strain theory. Then, these distributions are compared to the distribution based on the torsion theory of shaft having square cross-section, commonly known as the Saint Venant's torsion theory, and the distribution of modified theory that considers the elongation between gauge points. Moreover, the experimental results in this study are compared with the results of our previous study, which is obtained by applying only large torsion, and the effects of initial axial load on the shearing strain distribution are revealed.
MULTI-CRITERIA DECISION-MAKING METHODS FOR CONTRACTOR SELECTION: A REVIEW
Authors: KUNKCU HANDAN , KOC KERIM , GURGUN ASLI PELIN
Published: March 2023

The selection of an appropriate contractor is a prominent decision involving multiple decision-makers, which has a significant impact on the success of a construction project. In this context, considerable number of tools and methods have been proposed in the literature to assist decision-makers. This study aims to review existing literature related to the use of multi-criteria decision-making (MCDM) methods in contractor selection problems. To achieve the study objective, journal articles published between 2000-2021 were investigated by using the Scopus search engine and classified into various categories (year, journal, methods, project type, and country of origin). Findings indicate that many researchers adopted different decision-making methods for contractor selection such as AHP, ANP, PROMETHEE, TOPSIS, VIKOR as well as fuzzy logic-based decision-making approaches. The review of existing studies regarding MCDM methods for contractor selection could present a comparative ground on the applied methodologies. This study is also expected to help researchers identify holistic strategies to implement MCDM methods in various contractor selection problems.
END CONNECTIONS OF TUBULAR MEMBERS BY CIRCULAR PLATE AND CENTRAL FLANGE
Authors: VAN BOGAERT PHILIPPE
Published: March 2023

The connection of tubular members, used as bridge hangers or in 3-D coverings, has been widely researched, both for resistance and for fatigue. Such members are also often used in scaffoldings or as lighter bracings. The connection of the tube to a single bolted or welded plate consists of a circular end plate, covering the tube’s cross section on which a perpendicular rectangular plate is welded. No analytical approximation is available to calculate stresses in such a circular plate. Hence, FE-models have to be used for each application. As this is time consuming, a systematic survey of normal and shear stress has been conducted, for 6 unity connection forces of the gusset plate. The latter are normal force, shear in 2 directions, torsion and bending moments in 2 directions. The 3 types of stresses are kept separate, to allow for linear superposition, simulating any kind of real situation. The tube diameter and plate thickness have been varied to allow regression and obtain closed formulas. It appears that larger tube diameters have the capacity to distribute force, albeit the stress should be larger due to the increase of diameter. The former effect seems to overrun the latter and stress conditions are lower for wider tubes, which is rather surprising and may prove to be useful in practice. This is also confirmed by the displacement patterns, which show larger effective width of the higher diameter circular plate.
THE USE OF ULTRA-HIGH STRENGTH CONCRETE (UHSC) WITH LONGITUDINAL GFRP REINFORCEMENT UNDER FLEXURE
Authors: Mahaini Zin , Abed Farid
Published: March 2023

This research investigates the behavior of ultra-high strength concrete (UHSC) beams with GFRP reinforcement under flexure. The design parameters included the type of longitudinal reinforcement (GFRP or steel), as well as the reinforcement ratio (0.26%, 0.41%, and 0.67%). The beam specimens had a width of 185 mm, a depth of 250 mm, and a total span length of 2200 mm. All the beams were developed with 140 MPa concrete and tested in a four-point bending setup. The test results revealed that increasing the GFRP ratio improved the flexural capacity of the tested beams. By increasing the ratio from 0.26% to 0.41%, the moment capacity increased by 47.5%, whereas increasing the ratio from 0.26% to 0.67% increased the capacity by 76.4%. Moreover, the steel-reinforced beam reported a smaller moment capacity and mid-span deflection values as compared to its GFRP counterpart. Overall, the ACI 440 code provided a good description of the behavior of FRP reinforced beams developed with UHSC.
COMPARISON OF WIND INDUCED RESPONSE OF HIGH-RISE BUILDINGS WITH REINFORCED CONCRETE AND CROSS LAMINATED TIMBER
Authors: Dernayka samar , Ahmed Danish , Asiz Andi , Ayadat Tahar , Ajmal Muhammad
Published: March 2023

The main objective of this paper is to examine the wind-induced structural response of high–rise buildings constructed in the Kingdom of Saudi Arabia using reinforced concrete and lightweight cross-laminated timber (CLT) floor systems. Two major analyses were performed on two regular reinforced concrete (RC) buildings of 200 m height located in Dhahran and Jeddah. In the first instance, numerical simulations to obtain wind induced displacements and accelerations were conducted using computer software ETABS, SAP2000 and analytical model derived from building code. Then, another simulation of the building models was performed under similar wind conditions and same design criteria but by replacing the RC slabs of the buildings by cross laminated slabs. The wind data used for simulation was based on hourly wind data collection for the last 11 years (2009 – 2019). The results revealed higher story drift for both floor systems, whenever the wind speed is higher. The comparative analysis of the wind induced structural responses of traditional RC and CLT slabs showed greater accelerations at the top of the buildings with CLT floor system. However, the usage of CLT slab seems to be more feasible in the KSA considering adjusting designing lighter beam, column, and shear wall elements due to inherent CLT lightness.
TECHNIQUE TO DETERMINE DEPTH OF DEFECTS IN CONCRETE USING INFRARED THERMOGRAPHY – A SIMULATION STUDY
Authors: Naik Madhuraj Kiran , Hegde Ganesh , Giri Lalat
Published: March 2023

The cracks and damages in concrete can occur during the construction, placement, curing or any time during the service life of the structure. Cracks and damages can indicate concrete deterioration. Structural engineers are interested in the identification of damage location and crack depth measurement. The crack and damage depth measurement can help contractor in evaluating the repair costs. There are different methods to measure the crack depth like Impact-Echo Method, Ultrasonic Pulse Velocity (UPV) which can be employed where location of the cracks and damages are accessible. However, sometimes location of crack and damage in the concrete is inaccessible and this requires non contact measurement methods for identifying damages. Infrared thermography can be effectively used in identifying subsurface cracks and damages in such cases. The research work reported in this study is to identify depth of sub-surface defects located in concrete structures. The depth of damage is identified by taking infrared images of concrete surface. A pseudo experiment of thermal imaging was conducted on concrete surface using FEM simulations. A concrete slab model having inbuilt defects of known thicknesses and at known depths from the surface is used. The surface of slab is subjected to thermal excitation of varying amplitude and time period. The temperature contours on vertical sections passing through the defects are used to accurately determine the depth of damage. Using this technique depth of defect could be determined with a least amount of error up to 2% of actual depth. The results of simulation study are reported.
BLAST LOADING EFFECT ON CHEVRON TYPE BUCKLING RESTRAINED BRACED FRAMES
Authors: CHARCO OSHMAN , Chavarin Frank , Ahmad Rais
Published: March 2023

Buckling Restrained Braced Frames (BRBF) are being used all over the world as a seismic force resisting system in building structures. BRBFs are used due to their high ductility after yielding and the ability to absorb energy. Currently, American Society of Civil Engineers (ASCE) permits the use of BRBFs as a single seismic force-resisting system by quantifying the seismic parameters such as Response Modification Coefficient (R), Over-strength Factor (Ωo) and Deflection Amplification Factor (Cd) in their latest code ASCE 7-16. The purpose of this research is to investigate how a structure built with BRBF to resist seismic forces behaves when subjected to blast loading. In other words, this paper focuses on the effect of blast loading on Buckling Restrained Braced Frames. The investigation is carried out on a Chevron type braced frame. The frame is subjected to a short duration blast loading that lasts only 21.7 mili-second (ms). Blast loading effects on the braced frame are assessed by identifying the weakest plane of failure, deformation characteristics and out of plane bending. The research also investigates the effect of brace core thickness on resisting blast loading. It is observed that the brace core thickness plays a significant role in reducing the deformation characteristics.
COMPARATIVE STUDY OF MODIFIED CONSTRUCTION STAGE ANALYSIS AND CONSTRUCTION STAGE ANALYSIS FOR RC BUILDINGS
Authors: Desai Nehal , VASANWALA SANDIP
Published: March 2023

A significant difference is found in axial shortening of vertical members in tall concrete buildings when analyzed by Construction Stage Analysis considering the effect of creep and shrinkage as compared to the conventional One Step Analysis method. In Construction Stage Analysis the self-weight of structural members, and a load of brick walls along with floor finishing load, gets added sequentially as construction is carried out. In addition to the above loads, construction loads such as the weight of formwork, the weight of wet concrete, staking of materials, and other construction loads of men and machines get imposed on the structure during construction. Also, stagewise reduction of load due to removal of formwork, material staking, and other construction loads of men and machines should also be considered during the analysis with the Construction stage method. The axial shortening of vertical members of RC buildings was analyzed by the Conventional one-step method, Construction Stage method, considering self-weight along with brick wall and floor finishing load as sequential loads. Modified Construction Stage method-in which in addition to self-weight, brick wall, and floor finishing load, above mentioned all loads that appear during construction, were added, and removed sequentially in the analysis, by taking 20,30, and 40 floor RC building models. Modified CSA gives 2.068% to 20.56% lesser axial shortening in comparison to the CSA method. The study also concludes that the difference of axial shortening between Modified CSA & CSA increases from first to a certain floor, after that it reduces till top floor.
CARBON FOOTPRINT OPTIMIZED DESIGN OF SUSTAINABLE REINFORCED CONCRETE COLUMNS USING DEEP LEARNING
Authors: Karabay Aknur , Utemuratova Raushan , Zhang Dichuan , Varol Huseyin Atakan
Published: March 2023

The objective of this paper is to present a neural network (NN) model for the sustainable structural design optimization of rectangular reinforced concrete columns under biaxial bending and axial loading to minimize the embodied carbon from concrete and steel. Using the loading combination, height, and concrete class, the model predicts the section geometry and reinforcement ratio. To train the NN, a dataset of 195 million designs was generated with the OpenSees library following Eurocode. The dataset spans six concrete classes and five different column heights. Using the estimates of the embodied carbon for concrete and steel, the designs were evaluated and filtered before training. To illustrate the performance of our model, 30 columns for different loads, heights, and concrete classes were manually designed and compared with the NN output. The results showed a 24% average reduction of embodied carbon for the NN predicted designs. In addition, the manual process took approximately six minutes per design, while it took the NN 1.2 seconds for the same task.