bluuebunny/crossref_metadata_2025 huggingface dataset:
EVALUATION OF STRATEGIES FOR THE REDUCTION OF WATER CONSUMPTION IN REAL ESTATE PROJECTS
Authors: Valenzuela Blanco Maria Ximena , Guevara Jose , Salazar John , Castelblanco Gabriel
Published: October 2023

Activities related to the construction sector consume a large amount of water; consequently, it is imperative to quantify the amount of water used in each project phase. Particularly the operation of a real estate project is characterized by being much longer than the other project phases, resulting in significant water consumption. This work aims to evaluate the impact of strategies in reducing water consumption during the operation stage of real estate projects. To achieve this goal, a baseline scenario of water consumption was developed for the operation stage of the real estate projects in the city of Bogota, Colombia, from 2022 until 2050. Strategies used to reduce water consumption during the operation stage of real estate projects were implemented to the baseline to evaluate their impact. The cost of implementing each measure and the monetary benefits obtained were analyzed to quantify the effectiveness of each measure. The results of this work allow determine whether certain strategies will have a better impact in reducing water consumption and generating monetary savings.
AN EXPERIMENTAL RESEARCH CONTRIBUTION TO THE USE OF CARBON NANOTUBES IN CEMENT COMPOSITES
Authors: Albu Shaqraa Abbas Ahmed
Published: October 2023

Indeed, cement is the second most widely used material after water, with annual global cement production exceeding 4 billion tons in each of the last ten years. Cementitious composites are favored in construction because of their high compressive strength, low cost of preparation, simple manufacturing method, and ease of usage. However, these composites have several drawbacks, including a low tensile capacity, poor deformation performance, and a high cracking tendency, all of which impact the long-term durability of constructions. Carbon nanotubes can reinforce at the nanoscale, which was not possible before. Experimental work was conducted, and specimens of cement pastes and mortars were cast toward testing the carbon nanotubes’ dispersion within the matrix. Carbon nanotubes are known for being very cohesive in their raw form and difficult to disperse into the water. Using ultrasonic energy (bath sonication) along with incorporating a polycarboxylate high-range water-reducing agent to disperse the multiwalled carbon nanotubes helped to achieve about an 18% gain in compressive strength for cement pastes compared to plain cement pastes. This observed gain in strength was evidence of reinforcement. Several aspects explain the restricted work of carbon nanotubes on the industrial scale, including the high price of carbon nanotubes, the absence of standards and confirmations, and the complexity of dispersions, mixing, transporting, casting, and sufficient curing procedures. However, these practical difficulties could be partially resolved by improving the dispersion method or using pre-dispersed carbon nanotubes, which would be encouraging and useful for further exploration at the laboratory scale and the industry floor.
SEA LEVEL RISE POSE CHALLENGES TO FOUNDATION CONSTRUCTION IN COASTAL REGIONS
Authors: Ahmad Syed Faiz
Published: October 2023

Research has shown that climate change has a major effect on rise of sea levels. The warming of the planet is the principal reason that is directly causing a rise in global mean sea level (GMSL). GMSL since 1880 has risen approximately 210–240 mm. This is about a third that is recorded in just the last two and a half decades. The current rate of rise is approximately 3 mm per year. Red Sea located on the west coast of Saudi Arabia can be termed as a minor ocean basin that has several distinctive characteristics. It does not have any river-inflow from outside. A study has recorded that from 1993 through 2000, the sea level rise in the Red Sea has been following a rate of 3.88 mm/year. This rate follows the pattern of the global rate of 3.3 ± 0.5 mm/year. Nevertheless, as per study from 2000 until present time, an increased rate of 6.40 mm/year has been recorded in the “sea-level” of Red Sea. On the other hand, the conditions of the east coast of Saudi Arabia along Arabian Gulf shows a 1 m sea level rise affects approximately 650 km2 of the land area. This research paper per se has examined the possibility that these sea level rise in both the east and the west coasts of Saudi Arabia are expected to affect a significant rise in the ground water table and hence pose challenges in foundation construction.
INTERFACE OF QUANTUM COMPUTATION AND ARCHITECTURE, ENGINEERING, AND CONSTRUCTION (AEC) INDUSTRY
Authors: Naderi Hossein , Shojaei Alireza , Rokooei Saeed
Published: October 2023

The ever-growing complexity of construction projects on the one hand, and the increasing use of emerging technologies in the AEC industry on the other hand, have significantly escalated computational complexity. This trend is expected to continue. However, conventional computing tools and technologies highly rely on classical computing techniques that may not be able to handle computational tasks which become larger and more complex over time. Quantum computing (QC) is a fast-evolving technology that promises to completely revolutionize the computation capabilities in various fields, including engineering, by enabling complex computations that currently are impossible or prohibitively time consuming. As a result, QC can be seen as a next-generation solution to address computational challenges arising in the AEC’s today and future. However, scant attention has been drawn to what the QC can bring to the AEC industry. This study reviews the existing QC literature to explore AEC applications that could benefit from QC-based methods, and the potential challenges associated with their implementation in the AEC industry. Illustrating a clear outlook of the potential advantages and challenges, the study also helps to set realistic expectations over the potential improvement that QC can offer over conventional techniques.
CONSTRUCTION LABOR SHORTAGE, CHALLENGES, AND SOLUTIONS: A SURVEY-BASED APPROACH
Authors: Kaluthantirige Piyaruwan , Silva Lahiru , Hewage Kasun , Kaur Gil Simrat Pal , Gill Aekamjot
Published: October 2023

The global construction industry contributes about 13% of the world’s GDP and employs over 7% of the world’s working population. Literature showed that the world’s construction industry is highly dependent on skilled labor, labor productivity, and workmanship quality. According to industry experts, there is a significant shortage of labor for construction activities due to various reasons that delay construction activities and reduce construction efficiency. Although this was discussed in various forums in diverse communities, a sustainable solution for this challenge is not straightforward. Labor shortages are mainly due to unpredicted market fluctuations, a lack of specialized skill development programs and a lack of career progression paths. Implementing state-of-the-art technologies and construction automation can be considered potential solutions to reduce the need for labor forces in the construction industry. However, the initial investment required for automation and the technical know-how are key barriers to deploying construction automation in small to medium-scale construction companies. The aim of this study is to develop survey-based solutions to an existing labor shortage and provide a scientific framework to attract and retain construction labor. The findings of this research will benefit builders, contractors, and policymakers to observe labor market behaviors and proactively adapt to market fluctuations to attract and retain needed labor and also for the municipal, provincial, and national level decision-making on sustaining labor and developing new talents.
PRIVATE FINANCE INITIATIVE AS A TOOL FOR BRIDGING THE INFRASTRUCTURAL DEFICIT IN DEVELOPING ECONOMIES
Authors: Ikuabe Matthew , Aigbavboa Clinton , Ngcobo Ntebo
Published: October 2023

A critical factor in the economic growth of any nation is its infrastructural development. For most developing countries, such as South Africa, the infrastructural deficit has been experienced over the years mainly due to low gross domestic savings. A viable tool in shoring up for the shortfalls of infrastructural investment is the private finance initiative (PFI), as it makes provision for private sector financing of construction projects. On this basis, this study seeks to assess the drivers of PFIs in the South African construction industry. Using a quantitative approach, the study elicited data from relevant stakeholders in the built environment. Retrieved data were subjected to data analysis methods such as mean item score, Kruskal Wallis h-test, and SNK post-hoc test. The analysis findings show that the most significant propelling measure for PFIs in the South African construction industry is overcoming public sector budget constraints, timely project completion, and improved service delivery. Based on the study’s conclusion, recommendations were made to help propagate the inclusion of PFI as an alternative for project financing in South Africa.
INFLUENCE OF ENERGY EFFICIENCY RENOVATION ON INDOOR CLIMATE
Authors: Run Keovathana , Dubé Jean-François , Cévaër Franck
Published: October 2023

The buildings of the 1960s are not designed for today’s conditions and sustainable building standards. One of the solution strategies is renovation, which is not only for energy conservation but also for quality-of-life improvement. However, achieving both factors at once is a challenge, mostly from a financial standpoint. For public establishments, their priority is on energy efficiency retrofits which in return could push the indoor environmental quality (IEQ) to the edge of the comfort zone. IEQ is correlated to the health, comfort, and performance of users according to previous studies. This paper presents a case study of university buildings that underwent an energy-efficient renovation, including the replacement of windows and the installation of walls and roof insulation and mechanical extract ventilation systems. The objective is to analyze if the target energy consumption is achieved while maintaining a good IEQ during the heating period. Using t-test statistics on in-situ measurements of the before and after renovations, the results have shown three important findings. One, the total energy consumption has been reduced by 67%. Two, the t-test shows a significant difference between before and after states, with temperature decreased, and CO2 level increased. Three, a higher CO2 concentration is due to a faulty ventilation control that provides half less of the initial design airflow rate to meet a healthy standard. Overall, both temperature and CO2 rates remain in acceptable ranges despite the variation, but it is crucial to evaluate the HVAC controls after the renovation for safety reasons.
PREDICTING ENERGY USE INTENSITY OF US HOTEL BUILDINGS USING CBECS MICRODATA
Authors: Palani Hevar , Acosta-Sequeda Juan , Derrible Sybil , Karatas Aslihan
Published: October 2023

In the United States, the commercial sector consumes 21% of the total energy use. With 14%, the ~47,000 hotels are considered to be the third main source of energy consumption in the commercial sector. Stakeholders in the hotel industry have shown significant interest in reducing energy consumption in hotel buildings. However, determining the primary factors that contribute to overall energy consumption is important to develop efficient and effective retrofitting strategies. To address this question, this study focuses on identifying the variables in hotels that contribute majorly to their energy consumption. To achieve that, this study utilizes different machine learning approaches for estimating the source of Energy Use Intensity (EUI) for US hotel buildings based on Commercial Building Energy Consumption Survey (CBECS) 2018 microdata. The findings derived from this research can significantly contribute to the optimization of retrofitting strategies and building design in hotel buildings, as well as the development of effective electrification strategies. Ultimately, this knowledge will empower decision makers to make informed choices that enhance energy efficiency and sustainability in hotel buildings.
DETERMINING THE SUCCESS FACTORS OF DISTANCE EDUCATION SYSTEMS IN ARCHITECTURAL EDUCATION
Authors: Metinal Yusuf Berkay , Gumusburun Ayalp Gulden
Published: October 2023

Architectural education is unique among the disciplines that provide studio-based education beside theoretical education. By the nature of education, architecture students spend most of their times at design studios. Design studios play vital role in architectural education, since they are not only physical spaces but also active learning environments. This characteristic of education requires face-to-face education and interaction. Due to the COVID-19 pandemic there was a forced transition at architectural education from face-to-face to distance education system in universities. This transition has brought both useful opportunities such as timelessness and locationlessness, as well as problems such as lack of communication and lack of cooperation among peers. The main disadvantage of distance education in architecture is dramatically reduction of the interaction between the instructor and the student. With the forthcoming waves of COVID-19 and any other force majeure, distance education systems may be compulsory. To increase the efficiency, determining the success factors of distance education system in architectural education is important. Therefore, the aim of this study is to explore the critical success factors of distance education systems in architecture education. To reach this aim a questionnaire was composed by researchers with systematic literature review and conducted to students who are studying at architecture schools in Turkey. Within the scope of this research, 232 architecture students were surveyed, and the results were analyzed statistically with the Relative Important Index. As a result, the most crucial factors affecting the success of the distance education system in architectural education were determined.
RESEARCH ON DETERIORATION DIAGNOSIS SYSTEM FOR BUILDING EXTERIOR WALL USING BUILDING INFORMATION MODELING
Authors: Liao Chu-Tsen , Chi Nai-Wen , Chang Meng-Hsiu , Kao Ta-Chun , Chang Heui-Yung , Lai Chi-Ming
Published: October 2023

The exterior walls of buildings in Taiwan often use tiles as external wall materials. When the deterioration occurs behind the tile, it is not easy to judge the problem from the surface. Infrared thermal imaging technology is a non-destructive testing, which can quickly and widely confirm the damage of the external wall tiles of the whole building, so it is often used in the deterioration diagnosis for old buildings. In this study, the risk levels were classified as A, B, and C from the information of thermal image temperature differences (2.01℃, 2.25℃, 2.65℃) experiment. If the temperature difference is greater than 5°C, the degradation grade is C2, and the hollowing rate behind the tile is 75%. First floor on the east side of the chemical hall, the actual building in National Taipei University of Technology, was taken as the research object. Build a Revit building information model, input basic building information, upload thermal images and actual photos, and judge the degree of building deterioration. There are 7 pieces in C1 level, accounting for 0.29%, 2 pieces in C2 level, accounting for 0.08%. The results will be visualized with a building information model for deteriorating exterior walls to provide university effective maintenance information.
PREDICTION OF SLOPES SAFETY FACTOR USING ANN AND TREE-BASED MODELS
Authors: LADOL SONAM , MITTAL SATYENDRA , JAKSA MARK BRIAN , JAIN KAMAL
Published: October 2023

Slope stability assessment is a non-linear engineering problem. The complex relationship between factors that affect slope instability is challenging to investigate theoretically and mathematically. This paper proposes the prediction of slopes safety factor, subjected to circular failure mode using artificial neural network (ANN) and two tree-based models using M5P and random forest (RF) algorithm. A dataset including 46 slope cases was divided into a 70/30 ratio to train and validate the model. The input parameters for slope stability evaluation include slope angle, slope height, cohesion, internal friction angle, unit weight and pore pressure ratio. The corresponding output parameter is a factor of safety (FS). The finest ANN structure was obtained as 6-7-1 using the trial-and-error method. The proposed model chooses elliot as the best activation function at a learning rate and momentum of 0.7 and 0.5 for the accurate estimation of FS. In validation phase of ANN, M5P and RF models, the coefficient of determination (R2) results as 0.94, 0.86 and 0.81, respectively. The result suggests that the developed ANN model provides higher accuracy than tree-based models which can be an effective tool for slope stability assessment. Furthermore, the significance of input variables for FS prediction has been investigated through sensitivity analysis, which identifies the complex relationship between the input and output variables. The accuracy achieved from the prediction model is crucial for preventing the risk of slope failure and increasing the slope safety during preliminary design stage.
GEOTECHNICAL EVALUATION OF SELF-BUILT HOUSING SETTLEMENTS NEAR THE SHORES
Authors: ESPINOZA-MAMANI ALEX ENRIQUE , ALFARO-ALEJO ROBERTO , BELIZARIO-QUISPE GERMAN , PILARES-HUALPA ISIDRO ALBERTO
Published: October 2023

The lake soils that were occupied by constructions cause serious geotechnical problems, but even more so they are linked to the self-construction, self-planning, and self-management of housing and its influence on poorly designed and poorly located support elements on the shores of the lake, in the city, from Puno, Peru. The objective was to determine which factors cause damage to the structures of a self-built house. Technical inspections were carried out on randomly selected homes with moderate and severe construction deficiencies, as well as characterization and dynamic light penetration tests in compliance with the technical standard E.050 and E.060 of the National Building Regulations of Peru. The results reveal that 60% of the interviewees were unaware of the studies and designs that should be carried out; In addition, it indicates that the houses present negative symptoms such as fissures and cracks in different parts of the houses analyzed, linked to settlement, humidity, and salinity, with consequences in the weakening of the foundations of the houses. It is concluded that there was negligence by the owners in the design and construction of the foundations of their houses, without technical direction and professional supervision with uncontrolled fillings and unreliable construction procedures, it is advisable to go to specialists to avoid future problems in interaction soil-structure
ENERGY EFFICIENCY AND CONSERVATION PROGRAMS FOR LOW-INCOME AND MINORITY HOMES
Authors: Chau Anh D. , Schmink Marianne , Taylor Nicholas W. , Jarrett Lynn M.
Published: October 2023

Energy conservation and efficiency at the household level are important measures to reduce inequitable energy burdens, promote climate resilience, and encourage an equitable transition to clean energy in the US. The Community Weatherization Coalition (CWC), a non-profit coalition, has provided free home energy and water surveys to improve energy efficiency since 2008, focusing on low-income residential homes of Alachua County, Florida. This paper discusses descriptive statistical results of the program in reduction of energy and water usage for 312 households in Alachua County that were served from 2016 to 2019. The findings indicate that the CWC program has provided an innovative and effective way to reduce the inequitable energy burden for low-income residential populations through volunteer-based home energy conservation services. The results highlight the importance of incorporating energy efficiency into efforts to promote the transition to clean energy and suggest how local government and utilities can leverage energy efficiency to increase the resilience of the community.
BASIC REQUIRED PROGRAM OF COMPACT HOUSE FOR ELDERLY WITH LOW INCOME
Authors: Sawangjaroen Choomket
Published: October 2023

This paper aims to develop basic designs of compact houses for older persons with low income in Thailand. Due to their low financial income, most Thai senior citizens end up in old, dilapidated houses with environment risks for falling or other serious accidents. In this work, a compact house was designed using the universal design concept to improve the quality of life for the elderly. There are three main areas in the house design: sleeping area, utility area, and bathroom, with a total area of approximately 17.6 sq.m. for a one-person residence. The house design is based on data collected through a questionnaire and field survey with more than one thousand participants. The result showed that the living pattern of Thai older persons are mostly similar. The sleeping and utility areas are shared, and in some cases, utility areas are also used for other purposes such as working and food preparation. Home improvement for Thai elderly people must also concern three aspects which are 1) community technology, 2) determination of space utilization (zoning), and 3) size. It was found that international standards can be slightly adapted to suit the locals’ behaviors, physiques, both in natural and social contexts. This paper would be beneficial for architects, designers, or anyone who interacts with house owners on their residential preference. Policy maker may use this as a basis for the cost analysis of house improvement policy for older persons in the future.
UNIVERSAL DESIGN HOUSE MODEL FOR ELDERLY WITH LOW INCOME
Authors: Sawangjaroen Choomket
Published: October 2023

This paper demonstrates the Universal Design (UD) house for Thai elderly with low income under the budget of 100,000 Baht (approximately 2,662 USD). Houses of older persons and people with disabilities mostly cannot be easily renovated because the house architectural structures are extremely dilapidated. The budget from Thai government for house renovation is insufficient, so additional budget from local government and other organizations is required to renovate or rebuild the elderly’s houses for their better quality of life. To ensure sufficient budget, policy makers should expand the budget to 100,000 Baht per household with criteria of the urgency of construction improvement, which are 1) environment, 2) health, 3) society, and 4) overall opinion of the community. The 100,000 UD house is designed and built as a 1:1 model that was first showed in Thailand Friendly Design Expo for satisfaction survey. Most of the participants agree that the budget should be increased (74.7%) and that the elderly’s house should be rebuilt (76.2%) rather than renovated (39.2%). The result on the 100,000 UD house model is that it should have at least the necessary zones, which are the sleeping area, bathroom, cooking area, area connected the sleeping area, and the multipurpose area that constitutes 30-40% of the total housing area. This research would be beneficial for the government in improving the quality of life of elderly, underprivileged people.
CHALLENGES OF THE SOCIAL HOUSING DWELLERS
Authors: Kajimo-Shakantu Kahilu , Amoah Christopher
Published: October 2023

The South African government embarked on social housing construction for the less privileged post-apartheid rule. This study sought to investigate the challenges faced by the inhabitants of the social housing communities in Bloemfontein. A survey approach was adopted to solicit information from 1893 social housing dwellers within 7 communities in the suburb of Bloemfontein. Descriptive statistics were used to analyze and present the data collected. The finding shows that the prevalent challenges experienced by the inhabitants in the social housing communities are an inadequate number of bedrooms, inability to extend their houses, lack of toilet facilities, unemployment, and household overcrowding. Despite the government's effort to improve the lives of less privileged citizens, prominent challenges hinder their living standards. Thus, undermining the policy objectives. The study gives the government and policymakers insight into significant challenges facing social housing inhabitants. Therefore, they can institute measures to address these challenges to enhance policy objectives achievement.
APPLICATION OF NEURAL NETWORK IN PREDICTING THE OUTCOME OF CONSTRUCTION DISPUTES
Authors: Patel Rutvik Amitbhai , Patel Mukul Binu , Patel Kashyapkumar Arvindbhai , Patel Dilipkumar Arvindkumar
Published: October 2023

Surat, India The Indian construction sector has become more organized after implementation of the Real Estate (Regulation and Development) Act, 2016. However, occurrence of disagreement between the stakeholders is still a raising question despite the well-established framework of the Real Estate Regulatory Authority (RERA). Project characteristics such as project cost, project type, project scale and anticipated completion time have an impact on causing these disagreements, which ultimately result in a dispute. The disputes might adversely impact the stakeholders associated with them and may lead the project to delay. In order to establish the interrelationship between the project characteristics causing delay due to disputes, an appropriate soft computing technique can be applied. Therefore, this study highlights the application of Artificial Neural Network (ANN) for forecasting the outcome of a dispute. The inputs for the ANN model are project costs, project type, land area acquired and anticipated completion time of disputed projects from RERA. The proposed ANN model of 4-6-1 feed-forward back propagation structure helps to satisfy the need for quick and accurate resolution of disputes with lowering the stress on the judicial system. Moreover, the stakeholders engaged in the dispute can potentially save a considerable amount of money and time if they have an insight of the potential outcome.
PREDICTING THE COMPRESSIVE STRENGTH OF PALM KERNEL SHELL CONCRETE USING FULL FACTORIAL EXPERIMENTAL DESIGN
Authors: Adetukasi Adesola Olayinka , Olowofoyeku Adeoye Moses , Ojuri Oluwapelumi , Mahachi Jeffrey
Published: October 2023

Research has shown that the strength characteristics of Palm Kernel Shell Concrete (PKSC) are highly dependent on the mix parameters. This paper, through series of trial mixes, aim to achieve a model by which mix proportions can be selected for a target compressive strength using palm kernel shell as aggregate in concrete. This was done by testing the compressive strength of concrete containing varying total aggregate-cement content from ratio 3 to 6 in steps of 0.7 and water-cement ratios of 0.50, 0.55 and 0.60. The palm kernel shell content too was varied as a percentage replacement of coarse aggregate from 0 to 100% in steps of 10. From the trial mixes, the maximum, medium and minimum values of concrete mix variables were determined. A three-level three-factor full factorial design of experiments was used to investigate their effects. A total of 32 tests were carried out, including five control experiments (center points). A linear regression model was employed to model the measured compressive strength, this model predicts the compressive strength from a combination of water-cement ratio, palm kernel shell content and cement content. The model yielded a good prediction of compressive strength and provided good correlations with the data used in this study. The coefficient of determination, R-squared was 0.985, implying the model is highly reliable. Moreover, the proposed model proved to be valid in predicting the compressive strength of concretes whose mix parameters varied from the data used to develop the model.
FINITE ELEMENT ANALYSIS OF UHPFRC CYLINDERS CONFINED WITH CFRP SHEETS
Authors: Al-Osta Mohammed A.
Published: October 2023

Many recently developed materials have proven their capability as retrofitting materials for different applications. These materials include carbon fiber-reinforced plastic (CFRP) and ultra-high-performance concrete with steel fiber reinforcement (UHPFRC). In this work, the influence of wrapping the UHPFRC cylinders with CFRP was investigated numerically. Different parameters were considered, including the grades of UHPFRC and configurations of CFRP. A 3D finite element model (FEM) of UHPFRC cylinders wrapped with CFRP under static loading was developed using nonlinear finite element software (ABAQUS). The model was first verified using the experimental results provided in the literature. After that, parametric studies were carried out to study the impact of grades of UHPFRC and the different confining CFRP schemes (fully and partially) on the overall behavior of strengthened cylindrical UHPFRC, as well as the impact of increasing the thickness of CFRP layers on the strength and ductility ratio of the confined specimens. The results indicated that using CFRP to warp the UHPFRC specimens significantly improved their strength and ductility. As expected, the use of CFRP to partially wrap specimens did not show a significant enhancement in the strength of the confined specimens when the CFRP layers were less than 60% of the height.
FLEXURAL STRENGTH OF KEVLAR EPOXY COMPOSITES ON DIFFERENT FIBER ORIENTATIONS
Authors: Danda De Gargi , Mitra Souren , Sarkar Soumya , Deb Anindya
Published: October 2023

Nowadays, polymer fiber composites are very popular due to its weight-strength ratio in various industries. There are different types of natural and artificial fibers used for different purposes, according to the strength requirements. Uni-directional and bi-directional woven fabrics are very common for commercial purposes. Here this paper is focused on the behavior of different orientations of bi-directional woven reinforced composites to improve the efficiency of the ability of composites to resist bending deflection when energy is applied to the structure, it determines the resistance to flexing or stiffness of a material. In the present research, the theoretical and practical method was used to calculate the flexural strength of composite material consisting of epoxy resin LY 556 (50%) with different fiber orientations of woven Kevlar fibers. Ansys 2020R version was used to study the effect on different shapes of Kevlar-epoxy composite material. The standard ASTM D790 was used for the laboratory test and Ansys program. the result analysis focused on the stress-strain variation with the orientation and shapes
DEVELOPMENT OF SHRINKAGE AND CREEP PREDICTION MODELS FOR HIGH PERFORMANCE CONCRETE BY FAST-ACCESS CLOUD-BASED DATABASE
Authors: Liao Wen-Cheng , Chern Jenn-Chuan
Published: October 2023

This study presents the first analysis system and fast-access cloud database for shrinkage and creep of high-performance concrete in the world, named “shrinkage and creep database in Taiwan”, SCDT. SCDT not only has the most comprehensive experimental data, including NU, JSCE, Europe and TW database, but provides design tool for researchers and engineers. It can further facilitate the development of prediction models for localized concrete. Users can obtain the shrinkage and creep curves based on their selected prediction models in SCDT. Comparisons of predicted results of selected models and test results in chosen database can be generated in seconds. Examples of development of shrinkage and creep prediction models in Taiwan based on model B4 by using SCDT to reflect high performance concrete characteristics in Taiwan is also presented in this study. Users anywhere in the world can easily access SCDT to browse and upload data, receive predictive results, or develop predictive models.
IMPACT OF COVID-19 PANDEMIC ON COMPETITIVENESS OF TOURIST DESTINATION CITIES
Authors: Sang-arun Nattapon , Khongouan Waralak
Published: October 2023

This manuscript aims to examine the impact of COVID-19 pandemic on competitiveness of the 22 major tourist destination cities. It contributes to the studies and academic literatures of urban competitiveness by analyzing that impact on perspectives of these cities between the pre-and post-COVID-19 pandemic in the context of Thailand. The data from official documents and spatial survey were employed for the method of Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) analysis. The results reveal that the competitiveness has been reduced by the pandemic especially on the international tourist destination cities. It also finds that other perspectives of competitiveness such as revenue, budget, gross product are decreased after that period of time. Additionally, the rankings of competitiveness among these cities are also changed as well. The results suggest that the key factors for recovery these cities are the necessaries to pay more attention to all perspectives of competitiveness by re-allocating recourses for responses at different kinds of spatial configurations.
FLEXURAL CAPACITY OF COMPOSITE BEAMS WITH AN INCREASED AREA OF BONDED STEEL PLATES
Authors: Bruwer Carl Pieter
Published: October 2023

The objectives of this research study is to demonstrate the increase in the flexural resistance of composite beams and to compare the theoretically calculated to the experimentally tested flexural capacity of reinforced concrete beams and composite beams. Four similar reinforced concrete beams were constructed for this research study with dimensions of 250 mm wide and 450 mm deep. The beams were reinforced with 2 Y12 bars in both the tension and compression zones and the concrete compressive strength (fcu) was34.5 MPa. The beams span 4500 mm and were loaded at third spans. A control beam (Contr), without a bonded plate form the base for the flexural strength comparison to three composite beams (CB). CB1 were strengthened with a 75 mm x 2 mm, CB2 with a 75 mm x 3 mm and CB3 with a 75mm x 4mm 350 W steel plate. The concrete surface was prepared by scabbling to expose the well-bonded large aggregate and the steel plate was dry grit blasted to a white metal finish to obtain a 100–140 µm blast profile. The steel plate was bonded to the concrete surface by means of Pro-Struct 618LV primer and Pro-Struct 617NS epoxy. The flexural resistance of composite beams increase as the cross-sectional area of the bonded plate increase. From control to composite beams is 40.46% for CB1, 64.77% for CB2 and 93.22% for CB3. Comparing the accuracy of the theoretically calculated to the experimentally tested flexural capacity is 0.02% for CB1, 0.04% for CB2 and 2.34% for CB3.
EVALUATING MESOSCALE STRAIN LIMIT FOR TRANSVERSE PLATE-TO-RHS X JOINTS
Authors: Ryu Ihyun , Lee Cheolho , Kim Seonhu
Published: October 2023

Recently, mesoscale strain limit has been introduced for finite element (FE) analysis and FE-based design of welded steel tubular joints. The strain limit criterion appears to be useful particularly for the joints made of high strength steels, considering their lower ductility and higher propensity to fracture failure when subjected to tensile strains. While the latest revised draft of ISO 14346 recommended the use of 5% principal strain as the strain limit for all kinds of tubular joints, a previous study by the authors has demonstrated that a limit lower than 5% principal strain may be required for welded plate connections. In this study, the load-deformation relationship and fracture failure of transverse plate-to-RHS X-joints are investigated to evaluate appropriate strain limit for such type of joints. Based on test and test-validated FE analysis with a high strength steel of grade 700 (i.e., nominal yield stress of 700 MPa), it is suggested that more conservative strain limit should be applied to transverse plate-to-RHS X-joints.
STRENGTH AND DUCTILITY EVALUATION OF THIN-WALLED STEEL TUBULAR BRIDGE PIERS UNDER CYCLIC LOADING
Authors: Mamaghani Iraj H.P. , Mwaura Njiru
Published: October 2023

Numerical simulations are being conducted on the behavior of thin-walled steel tubular bridge piers under cyclic lateral loading in the presence of constant axial compression loads. The effects of cyclic lateral loading on the behavior of the thin-walled steel tubular bridge piers have been evaluated through analysis of the hysteresis curve, envelope curve, stiffness, and strength degradation characteristics, and energy-dissipating capacity, including interaction effects of local buckling and flexural buckling, and post-buckling regimes. This study also compares the numerical analysis with experimental results available in the literature to validate the accuracy of the proposed finite element model. Based on this model, a range of relevant material and structural parameters will be investigated in future work. Numerous numerical specimens will be designed and analyzed, gaining further information about the influence of width-to-thickness ratio, Rt, column slenderness ratio, , material properties of the embedded shell plate, spacing of transverse stiffening ribs of the shell, height, and properties of partially infill concrete, and axial compression load.
HORIZONTAL ACCELERATION OF FLOOR-MOUNTED NONSTRUCTURAL COMPONENTS UNDER ROCKING MOTION
Authors: Bae Chang-Jun , Lee Cheol-Ho , Jun Su-Chan
Published: October 2023

Floor-mounted nonstructural components (NSCs) that are attached through various types of angles are susceptible to seismic damage as they experience severe rocking motion resulting from their slender geometric configuration. However, current design codes do not reflect such complex dynamic behavior and prescribe design factors based on simplified single-degree-of-freedom (SDOF) models, which might cause an under-estimation of seismic design forces. Therefore, to properly control their seismic damage, the complex rocking dynamic behavior needs to be thoroughly investigated. This paper analyzed the rocking behavior of the floor-mounted NSCs and their effects on the horizontal acceleration response. Floor-mounted NSCs and their mounting attachments were idealized as rigid blocks restrained by linear vertical springs at the corner of the block. The nonlinear equations for the rocking behavior of rigid block were developed, and the analysis was conducted based on the fourth-order Runge-Kutta integration method. First, it is shown that the resonance period of rocking NSCs is mainly affected by the NSC slenderness and the location of the center of gravity of the component. The horizontal acceleration tends to increase as the slenderness and the height of the center of gravity of NSCs increase. Based on the observations, some useful design recommendations were suggested for designing attachments of floor-mounted NSCs.
BUCKLING STRENGTH OF COLUMNS IN LOW-RISE MULTI-SPAN FRAMES EVALUATED BY THE STABILITY INDEX
Authors: Nishimura Takuma , Kido Masae , Tsuda Keigo
Published: October 2023

The objective of this study was to investigate the validity of the effective length factors for low-rise multi-span frames obtained by the stability index (SI) method, and SI is defined by the ratio of PΔ moment to story moment. The SI method calculates the buckling load based on the condition that the story with the maximum stability index is the first to lose its stiffness compared with the other stories at the time of buckling. The analytical parameters used in the present study were the stiffness ratios of beams and columns. The effective length factors obtained by the SI method were compared with the exact effective length factors provided by the buckling slope-deflection method. The story displacement Δ of the PΔ moments was calculated by the application of horizontal forces at the top of the column of each story. This paper outlines a valid process to evaluate the effective length factors using the SI method and demonstrates the impact of the horizontal force distribution and Pδ moments on the accuracy of the SI method in low-rise, multi-span frames.
FATIGUE REAL SCALE TEST COMPARISON WITH ACTUAL BRIDGE MONITORING
Authors: De Backer Hans , Outtier Amelie , Van Staen Gilles
Published: October 2023

In railway bridges, special attention needs to be paid to the interaction between the railway track and the bridge. Forces occur in the rails, as well as in the deck and the bearings of the bridge. These forces result in additional stresses, which need to be kept sufficiently low. Peak stresses due to e.g., temperature variations and bridge deck bending are especially to be feared at the bridge/abutment transition. Special rail fastening systems may be used to limit these additional stresses. Real scale tests were performed to verify the behavior of the track and the bridge equipped with such modified fasteners, which are designed to limit the transfer of longitudinal forces to the bridge. Based on the data from these tests, a detailed finite element model is constructed in this research paper. In contrast to the generally accepted modeling approach prescribed by international norms such as Eurocode NBN EN 1991-2 and UIC Code 774-3R, this research is performed, assuming the fact that the behavior due to track-bridge interaction can be simulated by a rail model supported by springs, i.e., without the need to model the actual bridge structure in detail. The results of these finite element model simulations are compared with data of a long-term monitoring program using strain gauges on all elements of the rails and support structure of an actual railway bridge in Belgium.
EVALUATION AND STRUCTURAL MODELING OF 200 m3 CIRCULAR TANK SUPPORTED WITH SOFTWARE APPLICATION
Authors: HUANACUNI-MAMANI WILLY MIGUEL , HUAQUISTO-RAMOS EDILBERTO , ALFARO-ALEJO ROBERTO , BELIZARIO-QUISPE GERMAN
Published: October 2023

Permanent constructions in drinking water systems are of primary use in the development of a population. The objective of this work was to perform a non-destructive surface evaluation and structural modeling of the 200 m3 supported tank under conditions in the town of Pomata, Peru. A sclerometer was used to determine the concrete strength of the circular wall and the lower base of the old tank. The structural evaluation of the old tank was carried out by applying the design tables of the Portland Cement Association (PCA) and modeling with reliable structural calculation software; likewise, in the old tank the spectral dynamic analysis was carried out with the design parameters of the Peruvian National Construction Regulations, structural standards E.020, E.030, E.050, E.060 and ACI 350-01, ACI 350-06. The same results were obtained for the annular and bending stresses in a static analysis using the PCA design tables. According to the technical evaluation of the old tank, which has a useful life of more than 20 years of use in the potable water system; a new tank with the same storage capacity and in the same location was proposed; in the static and dynamic spectral analysis the PCA tables and modeling with software were used; achieving similar results in both tanks. It was demonstrated that demolition is necessary.
EXPERIMENTAL RESPONSES OF HIGH-STRENGTH KC COLUMN WITH LARGE AXIAL LOAD
Authors: Lin Ker-Chun , Huang Jun-Kai , Chi Kai-Ning , Jhuang Sheng-Jhih
Published: October 2023

A kernel-confined (KC) column, which a reinforced-concrete (RC) column moves partial longitudinal reinforcements from conventionally placed on outer periphery of section to inner kernel-confined region (KC bar), was concerned in this paper. This paper mainly intended to investigate seismic behaviors of the KC column with large axial loads. There are six sets of high-strength RC column specimens with 600 mm × 600 mm in section to be conducted. Their design strength of concrete was 70 MPa, and steel grades of SD550W and SD790 were designed as the longitudinal and transverse reinforcements, respectively. The number and location of the KC bar and the number and strength of transverse reinforcement are key study parameters. Test results indicated that for all specimens, including KC columns, the testing maximum moments were larger than the computed moment from ACI model and their average value of overstrength ratio of the testing to the computed was 1.25. In addition, the strength obtained from the XTRACT software had a better prediction with an average error of 0.99. Based on test deformation results for all specimens, the amount of the confined reinforcement per ACI 318-19 with an axial load of 0.5fc’Ag, can provide 3% radian of inter-story drift angle capacity for the high-strength RC column.
DURABILITY PERFORMANCE OF HPC CONTAINING MK AND GGBS FOR MARINE ENVIRONMENT: A REVIEW
Authors: Gmawlue Jr Thomas Nynweph , Kumar Pankaj
Published: October 2023

High performance concrete (HPC) is designed to serve certain purpose and overcome certain environmental condition that normal concrete cannot achieve. Many supplementary materials in varieties of proportions have been incorporated to make HPC. This review study considered the partial replacement of cement by Metakaolin (MK) and Ground Granulated Blast-furnace Slag (GGBS). It provides information on the composition of marine environments and the mineral reactive admixtures as well as their usage while highlighting their behavior relating to chloride ion penetration, sulfate attacks and permeability. The scope of this study considers outstanding research articles, from 1980 to 2022, as well as major books on Marine Environment, Concrete Technology and Civil Engineering Handbooks as to reveal the various techniques that engineers and researchers have used to optimize concrete performance in marine environment. This study found out that the incorporation of MK and GGBS greatly improves HPC in marine environment but the pattern of their influence varies per the durability parameter; the increment in quantity of each mineral admixture incorporated in the concrete were found to have either progressive or retrogressive effect towards chloride ion diffusion and gas permeability but progressive enhancement trend when resisting sulfate attacks. Also, water to binder ratio greatly influence the HPC in relation to the admixtures. It is concluded that MK level from 10% to 15% and GGBS level from 40% to 60% have optimal performance in most harsh conditions of marine environment.
EXPERIMENTAL INVESTIGATION OF THE COMPRESSIVE STRENGTH OF CONCRETE-FILLED FRP TUBE CYLINDERS SUBJECTED TO FIRE
Authors: Abouzied Ahmed , Madkor Nourhan , Abdelfattah Waleed , Hamdy Mohamed
Published: October 2023

Concrete-filled fiber reinforced polymer tubes (CFFTs) are becoming an attractive system for many different structural applications, such as piles, columns, and piers. However, many engineers are hesitant to use FRPs in structure because of the lack of knowledge of their behavior when they are subjected to fire. This study presents test results of thirteen CFFT cylinders with tube thickness ranges from 1.9 to 4.3 mm subjected to direct fire for periods ranges from 2 to 15 minutes and compared to reference confined and unconfined concrete cylinder. The tubes are composed of filament wound E-class fiber immersed in polyester resin. The test results show almost no losses in compressive strength for 2 minutes burning period for all tested tube thicknesses. By increasing the burning period to 15 minutes, the residual compressive strength significantly deteriorated to 44%, 56%, and 74% of the referenced strength for the unburned tubes with thickness 1.9, 3.7, 4.3 mm, respectively. Further investigation and observations were recorded for the surface condition after exposure to fire.