bluuebunny/crossref_metadata_2025 huggingface dataset:
QUANTIFYING GLOBAL SEISMIC PERFORMANCE FACTORS IN DUAL SYSTEMS WITH BUCKLING RESTRAINED BRACED FRAMES
Authors: Yavarian Sipan , Ahmad Rais
Published: March 2020

Dual structural systems are commonly used in high rise buildings for various architectural reasons. Buckling Restrained Braced Frame (BRBF) is an emerging seismic force-resisting system that is currently being permitted by American Society of Civil Engineers (ASCE) to be used either as a single seismic force-resisting system or in combination with other seismic force resisting systems. In conventional practice, ASCE suggests that while using BRBF in conjunction with other lateral force resisting systems in a dual configuration, the lowest Response Modification Factor (R) pertaining to the softer system shall be used. This may result in significant overdesigning of structures as higher contribution from the BRBF system are often remain unutilized. This research aims at developing a methodology for calculating modified Response Modification Factor, R for structures where dual system occurs horizontally. This research investigates the effect of using the newly suggested Response Modification Factor (R) for dual systems, where a BRBF system is combined with an Intermediate Moment Frame (IMF). The study aims at proposing an innovative way of calculating Response Modification Coefficient (R), Over-strength Factor (Ωo) and Deflection Amplification Factor (Cd) pertaining to the dual system. A wide variety of archetype sets are designed following FEMA guidelines with modified R as trial values for different seismic zones. To validate the trial values for R, system over-strength and period-based ductility, nonlinear 3D static (pushover) analyses were performed. The nonlinear models directly simulate essential deterioration modes that contribute to collapse behavior. Afterwards, for collapse assessment, nonlinear incremental dynamic analyses are conducted.
USAGE OF DYNAMIC CONE PENETRATION TEST TO ASSESS THE ENGINEERING PROPERTIES OF SAND
Authors: Al-Amoudi Omar S. Baghabra , Aiban Saad A. , Hamid Abdulrahman M.
Published: March 2020

Saudi Arabia is witnessing unparalleled development for all types of construction, especially in eastern Saudi Arabia where the major oil and petrochemical industries are located. In this region, major projects are often located on sandy soils and it is difficult to assess the properties of sands using conventional methods. In this investigation, a laboratory program was conducted using the dynamic cone penetration test (DCPT) on sand samples with different relative densities (40%, 60% and 90%) that were compacted in a large scale mold (1600 mm diameter and 1500 mm height). The placement of sand was achieved through the pluviation and vibration techniques. Results of investigation indicated that the increase in the dry density was associated with a decrease in the dynamic cone penetration index (DCPI). Further, it was noted that the shear strength has a significant effect on the dynamic cone penetration test results. In summary, results of this investigation indicate that DCPT is an effective and reliable tool in the assessment of the properties of sand backfills.
PRACTICAL EDUCATION OF MIXTURE DESIGN FOR YOUNG ENGINEERS AT READY-MIXED CONCRETE PLANTS
Authors: Hirayama Junichi , Yoshitake Isamu , Inoue Mamoru
Published: March 2020

The demand for ready-mixed concrete in Japan has decreased in recent decades because various budgets for civil infrastructure have been reduced. Additionally, a large number of skilled engineers will retire in the near future. The numbers of ready-mixed concrete plants and employees have decreased gradually to almost 50 percent of the numbers 15 years ago. The lack of knowledge in mixture design should be a concern, especially to young concrete engineers in Japan. The goals of the present study are to pass on fundamental mixture design methods to young engineers and to develop an effective education program for young engineers. A competition was held between young and skilled engineers to design mixture proportions for a modern concrete and a historically produced concrete made from river aggregate. The educative competition confirmed that skilled engineers are better than young engineers in modifying a concrete design. A questionnaire survey completed after the competition showed that the education of young engineers should include the learning of skills and experiences from skilled engineers.
LABOR PRODUCTIVITY IN OFF-SITE CONSTRUCTION: A LITERATURE REVIEW AND IMPLICATIONS FOR FUTURE RESEARCH
Authors: Alazzaz Faisal , Whyte Andrew
Published: March 2020

Labor productivity, critically important to profitability in the construction, is one of the most frequently discussed topics in the industry, and yet at the same time, is one of the most poorly understood. A literature review was conducted with the aim to identify how labor productivity is studied in the construction industry and what methodological issues exist. The literature review also investigated leading studies in productivity factors in construction generally, and considerations of productivity in relation to the off-site construction (pre-fabrication) sector specifically. The paper outlines general approaches to studying labor productivity in the construction sector. The review found that productivity is usually discussed in the literature under at least three separate topics, namely, the delimitation of construction (what is the precise aspect of construction under investigation), the measurement of productivity (what inputs and outputs are considered), and the identification of the factors that explain productivity. The review found that three issues undermining investigations into productivity in the construction sector were lack of a uniform approach to studying productivity, neglect of relevant variables, and limited generalizability. From this finding, it is recommended that a multi-factor approach is used to analyze productivity in construction. Concerning productivity considerations in relation to the adoption of off-site production approaches to construction, the literature review found that opting to use prefabrication increased overall productivity, led to reduced crew sizes, reduced onsite congestion, reduced cycle time, reduced debris, reduced total structural cost, and improved constructability.
INFORMATION SYSTEM FOR MANAGING COST REIMBURSABLE CONSTRUCTION PROJECT
Authors: Kang Namhee , Kim Hyunjung , Im Haekyung , Choi Jaehyun
Published: March 2020

The project management information system (PMIS) has recently been developed by using the IT technology in order to implement advanced information management technology to construction industry in Korea. The PMIS has been applied not only to domestic construction projects, but also to some overseas projects executed by Korean construction companies. This study was performed to develop the PMIS that is tailored to the US construction IT market. The US construction IT market has been monopolized by the US-based IT companies, but other companies are recently emerging with competitive technology and market strategy. As a preceding study, existing systems commercially available were analyzed, and the required features of the PMIS were identified by analyzing the core elements of contract, process and cost management for construction projects in the US. The PMIS then was developed based on the aforementioned analysis results. The system includes the document management module with an internal electronic approval system, the cost-plus-based automatic labor cost calculation module, and the progress management module to support the integrated project cost management. In addition, the functionality of the developed system was verified by construction project management experts in the US via questionnaire survey. The PMIS, which was developed in this study, is expected to be applied not only to the US construction IT market as a system specialized for the US construction industry, but also to other overseas markets in the future.
INFLUENCE OF NEAR-SURFACE MOUNTED FRP WITH CEMENTITIOUS MATERIAL ON OUT-OF-PLANE BEHAVIOR OF REINFORCED MASONRY WALLS
Authors: Aljaberi Zuhair , Myers John J.
Published: March 2020

Eight medium scale reinforced masonry walls were built as a part of this study. These reinforced walls were strengthened using carbon fiber reinforced polymer [FRP] (bars and tapes) and glass FRP (bars) using a near surface mounted technique (NSM) with cementitious material; constant mild steel reinforcement ratio (ρ) was used. These strengthened walls were supported as a simply supported wall under an out-of-plane cyclic load applied along two line loads. This study presented the effect of different parameters, these parameters related to FRP (type and amount), bond pattern (stack and running), and existing of FRP in compression face of the walls. This paper reveals the relation between these factors and the out-of-plane capacity of the reinforced wall strengthened with FRP. Different modes of failure occurred in the strengthened reinforced walls, including a punching shear failure through the concrete block, crushing of concrete block and debonding of FRP reinforcement from the masonry substrate.
CURRICULA DEVELOPMENT IN CIVIL AND STRUCTURAL ENGINEERING EDUCATION
Authors: Quapp Ulrike , Holschemacher Klaus
Published: March 2020

German civil and structural engineering education is experiencing major changes for the last 15 years mainly based on the Bologna Treaty. This research focuses on the question on how the curricula in civil and structural engineering programs have changed over the last 15 to 20 years, especially due to a) the requirements of the Bologna Process, and b) to the influence of non-academic organizations such as. professional associations. The conclusion is that these curricula have been greatly modified. Study programs leading to a first-cycle degree were shortened and interdisciplinary courses were included. Because of the increasing importance of interdisciplinary courses, and of general subjects such as presentation techniques, foreign languages, and career guidance, the time devoted to specific technical subjects and internships had to be reduced. This raises concerns within the industry about whether students bachelor graduates will be able to work professionally.
EFFECTIVE IMPLEMENTATION OF CONTEMPORARY PRINCIPLES ON LEARNING AND TEACHING A FUNDAMENTAL FIRST-YEAR ENGINEERING COURSE
Authors: Zhang Y. X. , Yang C.
Published: March 2020

Statics is the most fundamental component of Engineering Mechanics, and it is usually delivered in the first year in a common core course for engineering programs. The delivery of this key unit to the fresh first-year engineering students is very challenging and thus teaching pedagogies, strategies and methods should be further developed in response to the challenges in this important course which critically facilitates the transition of the students from high school to university and establishes their foundation knowledge on Engineering Mechanics. This paper reports the effective implementation of contemporary learning and teaching principles in a first-year core engineering course-Statics. The learning and teaching activities designed in this course include independent learning and collaborative learning, problem and project-based team work and peer learning, and progressive assessments. Effective teaching pedagogies, strategies and methodologies are developed on the basis of these educational principles to engage and motivate the first-year engineering students at most. The proposed methodologies are demonstrated effective in engaging a medium to large size class and the results of formal course surveys demonstrate the efficiency of these methods.
ANALYTICAL STUDY OF PILED-RAFT FOUNDATIONS CONSIDERING PLAN GEOMETRY AND NONLINEAR BEHAVIOR OF GROUND
Authors: Yamamoto Haruyuki , Huang He
Published: March 2020

The piled-raft foundation transfers loading to the ground by the raft and the piles together. It was proposed in the 1970s and is widely used for controlling settlement. Simplified estimate equations are used for the primary design. Equations by Randolph can presume the settlement stiffness of the piled-raft foundation and the loading share ratio from the settlement stiffness of raft and pile foundation. Raft foundations not only have regular shapes as squares, they also have some particular shape like triangular or L-plan. Therefore, different shape plans are discussed in this paper to verify the applicability of these equations. Also, these equations are proposed based on a theory of elasticity. However, the ground has nonlinear behavior even under small loading levels, so estimating the applicability of these equations when the ground behaves nonlinearly is necessary.
GROUNDWATER ASSESSMENT IN A CITY SUBURB
Authors: Adu Joy T. , Adebakin Idowu H. , Abiona Olaleye
Published: March 2020

Owode, a sprawling water catchment area better known for its commercial activities in metal and iron casting and fabrication, is located off the Lagos Lagoon and the Ajuwon River, in Lagos State. The extensive iron and steel work along with seasonal flooding of the area and the habits of the people in this area is considered a threat to its groundwater integrity. Samples designated SW1, SW2, and SW3 for stream water WW1, WW2, and WW3 for well water and BH1, BH2, and BH3 for samples collected from boreholes were collected and analyzed to determine the presence of certain physicochemical elements and heavy metals. Including pH, EC, TDS, DO, SO42-, Cl, NO3-, and PO43-. Heavy metals analyzed include Fe, Pb, Zn, Cu, Cr, Cd, and Mn. The findings showed that while a number of parameters when compared with the WHO and NADWQ stipulated maximum acceptable concentration fell within acceptable limits, others especially the heavy metals had trace elevations above the maximum acceptable levels which if not checked could have serious future groundwater contamination implications.
ANALYSIS OF EMPIRICAL COMPRESSION INDEX EQUATIONS USING THE LIQUID LIMIT
Authors: Al-Khafaji Amir W. , Maillacheruvu Krishnanand Y. , Sainz Matthew , Neuman Rebecca
Published: March 2020

This paper proposes a new method to evaluate the reliability of published empirical formulas in terms of accuracy and applicability to different soil types. Different empirical models are proposed to properly approximate the compression index for a wide range of liquid limits and soil types. They were developed using a unique Soil Property Line (SPL) developed using a substantial number of published regression equations and compression data. Familiar empirical equations were examined for their reliability in predicting the compression index of clay for any liquid limit. A comparison was made between available and newly-proposed empirical formulas using combined regression data sets compiled independently by several authors. The newly proposed empirical compression index equations are applicable to wide ranges of clay soils, validating other published relationships. The degree of scatter and variations in the computed compression index values are minimized for any liquid limit.
QUANTIFICATION OF INSTALLATION INACCURACIES AND THEIR EFFECT ON THE DESIGN OF SEGMENTAL TUNNEL LININGS
Authors: Schotte Ken , De Wulf Alain , Van Bogaert Philippe , De Backer Hans
Published: March 2020

The design of segmental tunnel linings requires a clear identification of loads during construction. Displacement monitoring of the Liefkenshoek tunnel in Belgium has shown important deformations occur in the first week after installation. Afterwards no significant deformations are measured. The manually-operated segment installation causes significant imperfections in joints between segments. These remain present during the lifetime of the structure, permanently disrupting the natural force transfer between individual tunnel segments. The joint irregularities obtained from ovalization measurements were used as input in an FE-model. Calculations showed that the resulting deformations do not correspond to the classical predictions. The installation imperfections cause a transfer of normal forces to the neighboring rings via friction in the ring joints. At the same time the bending moments show a distinctive disturbance in respect to the perfect tunnel ring. These results prove that the effect of installation imperfections should not be neglected in the design of segmental tunnel linings.
FAST PROCEDURE TO ASSESS THE RISK OF LOSSES FROM EARTHQUAKE IN R/C BUILDINGS
Authors: Mezzi Marco , Comodini Fabrizio , Fulco Alessandro
Published: March 2020

A simplified procedure for the risk assessment of the consequences of a seismic attack on an r/c building is presented in which the seismic hazard is taken from the probabilistic definition given by the national code and the vulnerability of the structure is evaluated according to a multi-scenario view. Three damage scenarios characterized by the extension of the structural collapses are considered for the risk evaluation. For each scenario the expected consequences on the building and occupants, injured and casualties, are computed. The calculation of consequences is based on the evaluation of a damage indicator that takes into account the extension of collapses of structural and non-structural elements. A risk indicator expressed in terms of annual probability of expected losses is finally determined.
COMPARISON OF LEED’S ENERGY AND ATMOSPHERE STANDARDS FOR SOME DEVELOPING COUNTRIES
Authors: Komurlu Ruveyda , Arditi David , Gurgun Asli Pelin
Published: March 2020

All efforts for handling resources, including extraction, processing, transportation, and manufacturing require energy. Thus, energy is a very valuable, albeit an indirect resource in the development of any country. Dependence on energy has a direct impact on the environment as well as the cost of products. Sustainability efforts focus on minimizing environmental impacts within a reasonable cost. Green building rating and certification systems around the world handle energy-related issues by considering the regional priorities of the country where they were first introduced. Certification systems rely on standards that are in effect locally. Leadership in Energy and Environmental Design (LEED) was first introduced in the U.S. and is currently the most widely preferred green building certification system around the world. The “energy and atmosphere” category in LEED v4 NC amounts to 33 points, which corresponds to approximately 26.2% of the total points that a building can receive. Because LEED was first introduced in the U.S., it heavily relies on U.S. standards such as ANSI/ASHRAE/IESNA, which limit its applicability in countries other than the U.S. In this study, the standards that are referred to in the energy-related categories of the Pearl Building Rating System (ESTIDAMA) of Abu Dhabi and LEED-India are analyzed and compared to the standards referred to by LEED v4 NC. It is hoped that the outcome of the study will provide valuable knowhow for professionals in other countries where efforts are underway to improve existing standards and/or to introduce new ones.
DEVELOPING ALIGNMENTS WITH GREEN BUILDING FOR A PROJECT HOME MARKET
Authors: Price Heidi
Published: March 2020

Presenting an analysis on the project home market in Perth WA; this paper looks at developing alignments for greener housing solutions, focusing on ways to change public and industry attitudes. At the turn of the Millennium, Scholars collaborated that green building was not an emerging trend; however, current research suggests otherwise. These investigations of this paper highlight a vision towards a more deliberate green trend thrusts bettering the outlook for a green Perth project home market. The UN’s had a MDG’s summit in 2010, expressed a need to developing sustainable building that can be measured. The background information to Perth’s current market in the paper is providing a foundation to insight the practices that are can assist in the initiation change and removal of barriers. It concludes that the developing green alignments seem not to be translating to greening Perth’s project home market. However, the acknowledgement of onus lies on homebuyers and the construction industry. Construction businesses need to use green marketing tools to highlight their social responsibilities and motivate green thinking. Moreover, it is to be understood that a maturing in green practices will cause the industry to say ‘Green is the only way to remain competitive’. Therefore, businesses need to adopt better managerial practices to filter throughout the construction process for viability of affordable green projects homes.
OPTIMIZING BUILDING UPGRADES TO MINIMIZE ENERGY AND WATER CONSUMPTION
Authors: Abdallah Moatassem , El-Rayes Khaled , Clevenger Caroline
Published: March 2020

Building sector in the United States is responsible for 41% of energy consumption, 73% of electricity consumption, and 14% of water consumption. Energy and water consumption of buildings can be significantly reduced by identifying and implementing green building upgrade measures based on available budgets especially in aging buildings which represent 70% of existing buildings in the United States. This paper presents the development of an optimization model that is capable of identifying the optimal selection of building upgrade measures to minimize energy and water consumption of existing buildings while complying with limited upgrade budgets and building operational performance requirements. This optimization model is designed to estimate building energy consumption using energy simulation software packages, is integrated with databases of building products, and performs analysis of replacing existing building fixtures/equipment and installing renewable energy systems during optimization computations to identify the replacement of building products that minimizes energy and water consumption. The model is designed to provide detailed results for building owners, which include specifications for the recommended upgrade measures and their location in the building; required upgrade cost; expected energy and water, operational, and life-cycle cost savings; and expected payback period.
EFFECTIVENESS OF CONCRETE FILLED FRP TUBES UNDER AXIAL LOADING
Authors: Kim Huigyeong , Suntharavadivel T. G. , Duan Kai
Published: March 2020

Concrete filled tube (CFT) has been widely used as an effective column structure because of the improved strength, ductility and stiffness as well as significantly reduced cost. Considerable studies have established that the improved performance of CFT columns results from the advantageous characteristics of both the tubes and concrete cores. It has been demonstrated that while the lateral confinement provided by the tube can improve the strength and ductility of the concrete, the concrete core will enhance the buckling strength of the tube. Currently, steels are the primary materials for the tubes because of their high strength and high stiffness. Over the past few years, fiber reinforcement polymer (FRP) has increasingly been used in structural application because of a number of its advantages over steels such as lightness, and reduced installing and maintenance costs among the other advantages. In line with this trend, a number of studies were reported on the use of FRP tubes in the CFT structures. This paper presents a brief state-of-art review of the application of FRP ‘can’ in structural engineering together with partial results from an experimental study of the behavior of a concrete filled FRP tubes under axial loading. The compressive strength of the FRP CFT and failure modes were obtained by varying the slenderness ratios of CFTs. The results are analyzed and discussed in terms of the effects of both slenderness ratio and lateral confinement due to the FRP tubes on the stress state and therefore, on failure mode and strength behavior.
CAN THE ACCELERATED PRISM TEST EVALUATE ALKALI-SILICA REACTIVITY?
Authors: Islam Mohammad S. , Ahmad Syed F.
Published: March 2020

The purpose of this study was to evaluate the alkali-silica reactivity of twelve aggregates based on the ASR-induced expansions of ASTM C 1260 and modified ASTM C 1293. The mortar bars and concrete specimens were prepared and fully submerged in the 1.0N NaOH at the temperature of 80°C. The ASR-induced expansions of the test specimens were recorded at various immersion ages. The expansion limits of alkali-cured prisms were proposed at the test durations of 4 and 8 weeks. Finally, the trial aggregates were classified based on the aggregate mineralogy and the expansion limits of mortar bars at 14 and 28 days, and they were compared with the proposed expansion limit of concrete prisms at the ages of 4 and 8 weeks. It was acknowledged that the 4-week failure limit of concrete prisms under the 1.0N resulted in some innocuous aggregates to be rated as reactive. However, the ASR-classifications of the trial aggregates showed a perfect correlation based on the results obtained from the extended failure limits of mortar bars and concrete prisms, and those from the mineralogy of aggregates.
DEVELOPING A CONCEPTUAL FRAMEWORK OF CARBON REDUCTION RESEARCH IN CONSTRUCTION
Authors: Wong Peter S. P. , Imperatori Francesco , Kakavoules Christian , Polastri Stefan , Acquaro Alessio
Published: March 2020

The construction industry has been proven to be increasingly detrimental to the environment in the past few decades. As environmental awareness expands, efforts to reduce the carbon intensive sector into a sustainable and environmentally friendly industry increase. It is indisputable that the efforts put in place to transform such a sector. Subsequently, the studies associated with carbon reduction development have also funneled into three streams: technology advancement, mechanism establishment and organizational behavior. However, research until now has focused on these streams independently. This paper presents a study that aims to take a holistic approach in analyzing the strengths and weaknesses of previous studies on carbon reduction in construction. A systematic review was conducted and the results came to expose five prevalent and determining factors that catalyze the success and failures of carbon reduction research. The discussion of these factors with their association to technology advancement, mechanism establishment and organizational behavior have uncovered suggestions, that researchers in future can focus on in order to foster carbon reduction within the construction industry. A conceptual framework of carbon reduction research in construction was then developed.
INDUSTRIAL BRIDGE CONSTRUCTION: NEED FOR A MORE EFFECTIVE BRIDGE CONSTRUCTION PROCESS
Authors: Ekström Daniel , Rempling Rasmus , Plos Mario
Published: March 2020

Designing for ease of construction is something that is always demanded by contractors and a challenge for the designers. It is widely known that the ability to influence a structure and its future properties is at its greatest in early stages, i.e. the project preparation phase followed by the design phase. Despite the fact that there is an obvious need for knowledge of construction in design work, there is a lack of a consistent and structured transmission of experience between the construction stage and the designing engineers. The results in this project are achieved based upon three standalone studies. A thorough literature review, a meta-analysis of the current research covering effective bridge construction and a study of the current industrial view on how the industry intend to achieve a more effective bridge building process. Based upon these studies it is clear that using a holistic approach and a production oriented design methodology is likely to generate the progress that the construction industry needs.
PROPOSED BURIED WEIGHT TEST AS METHOD OF TESTING FOR SETTING TIME OF CONCRETE MIXTURES
Authors: Maenaga Ikko , Suyama Hiroki , Takasu Koji , Koyamada Hidehiro
Published: March 2020

In this study, we examined method of test for setting time of concrete mixtures. Generally, the setting time of concrete mixtures is demanded by variation of penetration resistance, which is measured by manual labor for about eight hours. This measurement takes considerable effort. In late years, automatic devices to measure penetration resistance are commercially available, however the price is high. To solve these problems, we proposed a new low-effort and low-cost method: Embedded Weight Test. In the Embedded Weight Test, an embedded weight is hung with a line in the concrete mixture, and the tension of the line is measured by a data logger. The tension of the line had a variation point. The variation point is regarded as the time when the concrete mixture begins to vary from liquid to solid. As a result pf Embedded Weight Test with cement paste, the variation point of the tension was correlated with the initial setting time, which was defined by ISO 9597.Similar results were obtained when Embedded Weight Test was carried out with mortar. The variation point of the tension was correlated will help to estimate the time such as limits from mixing to the completion of placing or limit for intervals placing operations.
MECHANICAL STRENGTH OF SEALED-CURED NEAT CEMENT-PASTE
Authors: Walker S. , Choi W. , Picornell M. , Mohan R. , Hamoush S.
Published: March 2020

The strength of Portland cement concrete is dependent on the strength of the cement paste binding the aggregates together. An understanding of the cement paste is the first step to assess the concrete strength. To this end, a program for strength testing of cement paste was implemented for water to cement ratios of 0.35 and 0.40. The compressive strength was evaluated using two inch cubes and four inch diameter cylinders; while the tensile strength evaluation was based on flexure and direct tension tests. All the specimens were cured in the mold the first day, followed by curing in sealed vacuum bags for the remaining of the time. The total curing time ranged from three, seven, fourteen and twenty-eight days. Three replicate specimens were prepared, cured, and tested for each combination of water to cement ratio, type of specimen, and time of curing. The results of the testing program show that while the compressive strength increases for increasing curing time, the tensile strength shows a consistent decline. These results indicate that the sealed curing forced that further hydration caused “self-desiccation” of the CSH, inducing new cracks or extension of existing cracks that would be responsible for the loss of tensile strength.
STRENGTH PROPERTIES OF BACTERIAL CONCRETE CONTAINING FLY ASH
Authors: Kishore Ravande , Penchala Archana
Published: March 2020

The Paper describes the comprehensive experimental work carried out on M40 grade bacterial concrete containing fly ash. Two types of common soil bacteria namely, Bacillus Pasteruii and Bacillus Odysseyi with a concentration of 105 cells/ml have been used. The optimum cell concentration of bacteria was arrived at by studying its influence on compressive strength of cement mortar matrix. Fly ash of 10 % by weight of cement was used to partially replace OPC in the concrete mixture. The performance of M40 bacterial concrete containing fly ash was assessed by testing the standard specimen for compressive strength, flexural strength and split tensile strength at different ages of curing. Results of investigation indicate significant improvement in 28 days compressive strength in the range of 12% to 27%. Twenty eight days flexural strength and split tensile strength have also shown appreciable increase in the range of 4% to 14% and 11% to 24% respectively. In general, the results of investigation are encouraging and set in positive direction for use of Bacterial concrete in the construction sector during 21st century.
FUNDAMENTAL STUDY ON COMPRESSION COMPONENT OF HALF PRECAST CONCRETE
Authors: Sato Takeshi , Suyama Hiroki , Takasu Koji , Koyamada Hidehiro
Published: March 2020

In this study, we examined the compressive component of half precast concrete. Form work is unnecessary in half precast concrete, and it is able to reduce cost of the construction. In Japan, the damage of housing by Typhoon and Tornado occurs frequently in recent years. Therefore, there is a possibility that the construction of half precast concrete house will increase in the future. The section of half precast concrete is consisted of two kinds of concrete. However, most studies of concrete engineering have focused on single layer concrete. The studies of double layer concrete are not enough. It was confirmed that the maximum compressive load of the compression member increased by making the aspect of the mortar double layer of a shell and a core by the past study. In this study, we made non-line mortar specimen (diameter: 100mm) imitated half precast concrete column. By the experiment, we examined the design formula of maximum compressive load of half precast concrete. We proposed a design formula to add ΔP (increment by sectional constitution of plural concrete, 28 kN in this experiment) to Pms (maximum compressive load by calculating the product of the compressive strength, in consideration of the distortion in the specimen fracture, and cross-sectional area of the shell and core).
DEVELOPING AN UNCERTAINTY ANALYSIS MODEL FOR OFF-SITE BUILDING PRODUCTION
Authors: Arashpour Mehrdad , Wakefield Ron
Published: March 2020

The hybrid use of off-site and on-site processes in construction projects has increased significantly over the past decade. The analysis and management of uncertainty in hybrid projects is not a trivial task as workflow variability in off-site and on-site operations can interact and amplify one another. The aim of this paper is to analyze various drivers of uncertainty such as high levels of project complexity, risk seeking behaviors, unavailability of resources, and combined variability in hybrid projects. Production data of two Australian construction companies were collected and utilized in modeling uncertainty. Findings show the significant effect of uncertainty drivers on project plan reliability and the necessity of an adequate uncertainty analysis and management in hybrid projects. The results of this study enhance the knowledge about management of hybrid projects and have the potential to improve the way construction companies deal with uncertainty in project environments.
INFLUENCE OF CALCINED NANOCLAY ON FRACTURE TOUGHNESS OF NAOH-TREATED HEMP FABRIC REINFORCED CEMENT NANOCOMPOSITES
Authors: Hakamy A. , Shaikh F. U. A. , Low I. M.
Published: March 2020

influence of calcined nanoclay (CNC) on the porosity and fracture toughness of treated hemp fabric-reinforced cement nanocomposites is presented in this paper. Characterisation of microstructure is investigated using Quantitative X-ray Diffraction Analysis (QXDA) and High Resolution Transmission Electron Microscopy (HRTEM). An optimum replacement of ordinary Portland cement with 1 wt% CNC is observed through reduced porosity and increased fracture toughness of treated hemp fabric-reinforced nanocomposite. The microstructural analysis indicates that the CNC affect not only as a filler to improve the microstructure, but also as the activator to support the pozzolanic reaction and thus improved the adhesion between the treated hemp fabric and the matrix. Cost-benefit analysis indicates the benefit of such cement eco-nanocomposites to develop new environmentally friendly nanomaterials and it can be used for various construction applications such as, ceilings and roofs.
EFFECT OF MIXING PROPORTION ON COMPRESSIVE STRENGTH OF FLY-ASH BASED GEOPOLYMER PASTE AND MORTAR USING TAGUCHI’S METHOD
Authors: Afridi Sajid Khan , Vimonsatit Vanissorn
Published: March 2020

Alkali activated pozzolan are known low carbon cementitious binders which can be used to replace cement. The material is also known as geopolymer because of its three dimensional polymeric chain and ring like structure consisting silica and alumina. A common type of pozzolan used is fly ash because of its rich silica content; therefore the term alkali activated fly-ash based binders is adopted. Despite much research and development of this material, there is no specific standard for design mix proportion. This research used the Taguchi’s design of experiment method to determine the optimum mix proportion of alkali activated fly ash based cement paste and mortar. Four factors were considered in the tests, silica fume, sand to cementitious ratio, liquid to solid ratio, and percentage of superplasticiser. Tests were conducted on the 9 batches of alkali activated fly-ash based paste and mortar samples to determine the compressive strength under ambient condition. Tests were also conducted to determine the residual strength of the samples after exposed to elevated temperatures. ANOVA analysis of the test results revealed the main factors contribution on the tested properties and led to the determination of the optimum design proportion of the factors considered in these tests.
CERAMIC WASTE POWDER AS SUPPLEMENTARY CEMENTING MATERIAL IN CONCRETE MIXTURES
Authors: El-Dieb Amr S. , Kanaan Dima M.
Published: March 2020

Green environment is a challenging concern to accomplish in today’s world. This could be achieved through a beneficial recycling procedure by reusing solid waste materials. Ceramic tiles are widely used in most structures; its production creates waste powder. Concrete that contains solid waste is referred to as “Green” concrete. Using ceramic waste powder (CWP) as an alternative ingredient in concrete will have a positive environmental impact furthermore will help reserve natural resources. In this study CWP will be investigated as supplementary cementing material (SCM) in making concrete. The ceramic waste powder will be used as SCM with different dosages replacing cement. The effect of ceramic waste powder as SCM on the properties of fresh concrete will be investigated such as slump, slump loss and setting time. The properties of hardened concrete will be assessed through compressive strength development, drying shrinkage and durability characteristics was evaluated by rapid chloride permeability test (RCPT) and bulk electrical resistivity. Test results show that CWP can be used as SCM in making concrete. The outcomes of the study shed light on how CWP could be utilized effectively as an alternative ingredient of concrete and the optimum dosage for use which will result in an effective way for using solid waste and protecting the environment.
SEISMIC PERFORMANCE EVALUATION OF ASSEMBLED O-STABLE PANEL WALLS
Authors: Chen Shiming , Zhuang Bingrui , Gu Ping
Published: March 2020

O-Stable Panel is a new type of assembled structural wall. To evaluate the performance properties of the O-Stable Panel system, three integral prefabricated panel specimens with different vertical connections at the bottom and one full cast-in-place panel specimen were designed and tested under the low cycle lateral reciprocating loading. The performance of the prefabricated O-Stable Panel systems with different vertical connection configurations was compared with those of the full cast-in-place panel. The investigation reveals that all prefabricated O-Stable panel specimens developed vertical cracks penetrating through thickness of the panels at the panel joint and at the positions where panel thickness variation occurs at the ultimate failure state. The O-Stable panels possess the likely symmetric and stable hysteretic curves and no pinching appearance in shape of the curves. The panel with grouting sleeve in vertical joint for steel rebar appears sharp degrading in seismic index as the lateral drift of the wall increases beyond yield of the panel. For the assembled panel with preinstalled rebar stretched into the foundation beam for the vertical rebar joints, it has very close values in the hysteretic energy dissipation as that in the full cast-in-place panels.
THE RESPONSE OF THE COLUMNS OF SPECIAL MOMENT FRAMES UNDER AXIAL AND LATERAL LOADING CYCLES
Authors: Farahi Mojtaba , Erfani Saeed
Published: March 2020

In order to assess the boundaries of the simultaneous demands on the column members of Special Moment Frames (SMFs), a thorough investigation in the following research were performed on several different archetype frames. Beside the boundaries of the simultaneous seismic demands, the fluctuation of these demands was also analyzed after numerous non-linear dynamic analyses on sample SMFs. These analyses paved the way to establish a representative framework for loading the column members in order to represent the seismic demands expected to be developed on these members. The maximum story drift among all analyses did not exceed 0.06, while a peak axial force more than 30% of their nominal axial yield strength was not captured among all the columns of the sample frames. Chosen archetype columns were loaded under introduced loading framework, and their response compared with the responses of the same columns when the lateral loading is implemented in conjunction with a constant level of axial loading.
DESIGN OF STEEL I-BEAMS WITH WEB OPENINGS
Authors: Calado Luis
Published: March 2020

The paper presents a numerical research on the behavior of steel I-beams with web openings. The influence of web openings in the load carrying capacity of steel beams and failure mechanisms are investigated. The non-linear numerical analysis performed was calibrated with results from other similar non-linear numerical analysis and experimental test data. Comparison between numerical results with the available experimental for yielding patterns, ultimate load values and load-deflection relationships show a good agreement. The numerical model developed was used to carry out a parametric study taking into account some parameters, such us: opening shape, opening size, and the location of the opening throughout the span. Three different beam spans were considered. A contribution to the analysis and selection of the web openings best solutions is presented in the conclusions.
Student concerns about their stay abroad: a comparison between British and German student concerns before and after their time abroad
Authors: Leahy Christine
Published: March 2020

While an extended stay abroad is generally assumed to be a valuable experience, some students are reluctant to take up the opportunity. To understand this phenomenon better, this study looks at students’ concerns before they embark on their time abroad (to undertake a study placement, work placement, or a language assistantship) and looks at returning students’ perceptions, to see the extent to which their initial concerns materialised. The research is based on two questionnaires distributed to over 800 participants at two universities (one in the UK, one in Germany). Besides quantitative data, qualitative responses give additional insights into the students’ perceptions. The results show marked differences between the two cohorts and also produce evidence of a considerable shift in students’ perceptions after their return: a high percentage of students noted that their anticipated concerns were not realised. The results of this study are useful in shedding some light on students’ concerns and can inform student support and Year Abroad (YA) preparation.
Embedding employability in year abroad preparation
Authors: Archer Leona
Published: March 2020

UK universities are increasingly focusing on employability and internationalisation strategies, resulting in the promotion and integration of an optional or compulsory Professional Training Year (PTY) within degree programmes. The University of Surrey encourages students to undertake a PTY in the third year of undergraduate study, either in the UK or overseas. This is optional for most subjects but compulsory for language students, and corresponds to their Year Abroad (YA). As a consequence of the popularity of the PTY across all faculties and an emphasis on work experience, the vast majority of language students at Surrey choose to work abroad rather than study during their third year. In this chapter, I discuss some of the challenges and opportunities presented by work placements abroad and outline a range of strategies for embedding employability skills in YA preparation sessions and language modules.
Queering Time: The Temporal Body as Queer Chronotope in Virginia Woolf’sOrlando
Authors: Mittal Biswas Pooja
Published: March 2020

This paper studies how the novelOrlandoby Virginia Woolf deconstructs the male / female gender binary by deconstructing the past / future time binary. The protagonist’s sex change disrupts the linearity of ‘straight time’, in which the causality of gender is monodirectional, queer agency is impossible, and a false equivalency is drawn between gender identity and biological sex. The text instead leads Orlando (and the reader) away from straight time and into queer time, which is multidirectional, non-linear and non-heteronormative, and which unhitches gender identity at least partially from biological sex through a process that I call ‘gender lag’. This lag grants queer agency to Orlando in terms of his / her own gender identity and gender performativity. In exercising queer agency, Orlando’s changing body becomes a queer ‘chronotope’, that is, a queer expression of time and space within the narrative. Explored in the paper are the various means employed within the text to queer time and gender. The cultural context within whichOrlandowas written is also considered as a contributing factor to the subtextuality of its queerness. Finally, the text’s transgender connotations are analysed.
Changes in the result of antinuclear antibody immunofluorescence assay on HEp-2 cells reflect disease activity status in systemic lupus erythematosus
Authors: Prado Mônica Simon , Dellavance Alessandra , Rodrigues Silvia Helena , Marvulle Valdecir , Andrade Luis Eduardo Coelho
Published: March 2020

Background

The objective of the study was to determine whether the staining pattern and titer of indirect immunofluorescence assay on HEp-2 cells (HEp-2 IFA) are associated with systemic lupus erythematosus (SLE) disease activity.

Methods

A total of 269 consecutive patients meeting the ACR and SLICC criteria for SLE were classified into three groups according to the SLE Disease Activity Index 2000 (SLEDAI2K): Remission (SLEDAI2K = 0; n = 47); Intermediate (SLEDAI2K = 1-5; n = 111); Active (SLEDAI2K ≥ 6; n = 111). All subjects were assessed for HEp-2 IFA titer and staining pattern and nine traditional parameters of SLE disease activity. After a 6 to 12-month interval, 101 of the 269 patients were reassessed.

Results

HEp-2 IFA homogeneous nuclear pattern (AC-1) occurred more frequently in the Active Group compared to the Remission Group (p < 0.001). Fine speckled nuclear pattern (AC-4) tended to occur more frequently in the Remission Group compared to the Active Group (p = 0.054). Subjects with AC-1 pattern had higher SLEDAI (8.8 ± 7.6) than those with AC-4 (4.8 ± 5.2) (p < 0.001). HEp-2 IFA titer and anti-nuclear antibody by enzyme-linked immunosorbent assay (ANA-ELISA) values were lower in the Remission Group compared to the other two groups (p < 0.001). Multivariate analyses identified only ELISA anti-dsDNA as an independent variable associated with disease activity. In follow-up analysis, HEp-2 IFA titer decreased significantly in the 33 subjects with decreased disease activity (p = 0.002). Receiver operator characteristic (ROC) curve analysis for determination of disease activity showed equivalent areas under the curve (AUC) for HEp-2 IFA titer and traditional disease activity parameters.

Conclusions

HEp-2 IFA pattern and titer can reflect SLE disease activity and may be considered in conjunction with other laboratory and clinical parameters in the assessment of SLE disease activity.