cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.12755/isec.res.2018.90
title: DIGITALISATION IN CONSTRUCTION INDUSTRY: CONSTRUCTION PROFESSIONALS PERSPECTIVE

description: This study presents the result of an assessment of digitalisation within the South African construction industry from the construction professionals' perspective. The study adopted a quantitative approach through a questionnaire survey carried out among construction professionals in Gauteng Province, South Africa. Appropriate descriptive statistical tools were used in analysing the data gathered. The study revealed that the major stages of construction where digitalisation is evident are the design phase, and the feasibility phase. The major construction processes where it is mostly visible are, construction cost control, cost planning, preliminary cost estimate and building system analysis. In addition, the most significant benefits to be derived from digitalisation in the industry includes time-saving in construction projects delivery, increase productivity, increase speed of work, increase document quality, speeding up of response time, and simpler working methods. This study contributes to the body of knowledge as it reveals the happenings surrounding digitalisation within the South African construction industry
description: an aspect that seems to be lacking research attention.
DOI: 10.12755/isec.res.2018.91
title: Durability and Pozzolanic Reaction of Fly Ash Concrete Exposed to Various Outside Environments

description: In this study, outside exposure tests of fly ash concrete were started in 2009 at various places in Japan in order to assess the effect of the differences of the exposure environment on the variation of long term durability of fly ash concrete and the degree of pozzolanic reaction of fly ash. This paper shows the results of durability monitoring over seven years from the start of exposure testing and the degree of pozzolanic reaction after seven years. The durability of fly ash concrete is improved due to pore structure complicated by the pozzolanic reaction. The degree of pozzolanic reaction of fly ash in concrete exposed under any conditions ends up being the same when enough time has elapsed, such as seven years, regardless of differences in exposure conditions.
DOI: 10.12755/isec.res.2018.92
title: ECONOMICAL STABILIZATION BASED ON TURK SALTY MORTAR AND GROUTING PROBABILITY FUNCTION IN SALTY FORMATIONS

description: GOTVAND reservoir dam is located in the Karun River, SW of Iran. Dam Lake's coastline is covered by the salty ridges 500,000,000 tons with 5000 m coastlines length. Layers are combined by Salt, Gypsum, clay, Marl, Silt and dolomite. TSM- Turk Salty Mortar was invented in order to stabilize the salty ridges. Components of TSM are salty water, clay, bentonite and cement. Proportion (% of total by mass) is 65% salty water, and 35% other materials. It is estimated that salty materials inter the lake by 1300 tons per day. Grouting Cost determines more than 1,000,000,000 USD in 2017 that the government was declared previously. TSM is contended to finish the work less than 100,000,000 USD (90% discount). Another suggested layout is based on the diverting the Karun River path. This research is fixed to stabilize salty domes in place. TSM grouting inside the layers needs to draw an accurate plan. Random variable interaction is defined through the salty layer and TSM. Also, it is recommended to use the -TGDF- Turk Grouting Distribution Functions for technical grouting and effective economical radius. ?P is the economical boreholes result that can be used to extend the length of grouting without cost. TGDF recommends the injection in salty layers only.
DOI: 10.12755/isec.res.2018.93
title: Education: a change agent for project failure?

description: This research paper seeks to critically assess the role of education in addressing the skills gap in managerial competences and resilience to project failure within the project management profession. In order to achieve this it will address issues relating to why projects fail. To conduct this research an unobtrusive approach is undertaken through the use of content analysis. Content analysis is used to examine the qualitative data drawn from 4 case studies on project failure. It will use a thematic approach and coding to identify emergent patterns and trends. This in turn will help to capture and identify lessons learnt that could be adopted to create a new model of educational and leadership competences for project managers. By encouraging more critical reflection in training and educational development programs, it is proposed that this will empower project managers towards a better understanding of their corporate social responsibility within their profession. This paper concludes that failure to properly educate project managers has serious implications on their professional identity and credibility as practitioners, as well as for future pedagogical practice.
DOI: 10.12755/isec.res.2018.94
title: EFFECTS OF THE INITIAL DEFLECTION SHAPE ON THE MOMENT AMPLIFICATION FACTOR OF BEAM-COLUMNS

description: In the design of slender steel beam-columns, the moment amplification factor is used to estimate the maximum moment along with the longitudinal direction. While formulas for evaluating the factor have been presented on the basis of elastic or elastic-plastic analysis, the initial deflection of the column is not considered. The effect that the initial deflection on the strength and behavior of the column has been shown only when the initial deflection shape is half sine wave. This paper discusses the effect of the initial deflection shape on the value of the moment amplification factor by performing the analytical work. The analytical model is the hinged-end beam-column subjected to constant axial compressive force and end moments. First of all, the equilibrium differential equation which governs the problem is solved and the formula for calculating the bending moment is presented. In the parametric study, magnitude of initial deflection, initial deflection shape, axial load ratio, slenderness ratio and end moment ratio are selected as the parameters. In this paper, we discuss the effects of the amount of the initial deflection and the initial deflection shape.
DOI: 10.12755/isec.res.2018.95
title: Engineering Characteristics and Earthquake Response Analysis of Ground

description: One-dimensional layered soil lumped mass ground response analysis was conducted for the representative site in Ulaanbaatar, Mongolia. The surficial geology of the site is predominantly composed of the gravely and sandy soil typical of this region in the central part of Ulaanbaatar. The natural period of soil profiles needs to be investigated under several circumstances. For example, these parameters-based study has indicated that damage due to earthquakes occurs when the natural periods, T1 and T2, of the ground are closer to that of a superstructure. Various computational procedures or methods have been proposed for this kind of the ground response analysis. In this paper, the numerical analysis method such as the lumped mass method within eigenvalue analysis is used to determine the natural periods of the ground. The ground surface, soil deposits, and bedrock are assumed to be horizontal. The soil deposits are subjected to shear deformation such as shear modulus, G, on the other hand, excitation of vibration could be a shear modulus on each layer. As well as to determine an engineering bedrock depth in the site, the methodology that is utilized in this paper is focused on the use of the correlation between SPT-N value and soil elastic Young`s modulus, E, in the soil profiles, and used over 100 boreholes data with SPT-N values in the vicinity of Ulaanbaatar.
DOI: 10.12755/isec.res.2018.96
title: EVALUATING PERMEABILITY AND MECHANICAL PROPERTIES OF WASTE MARBLE DUST MIX CONCRETE AND BENTONITE MIX CONCRETE

description: In this research attempt is made to examine Waste Marble Dust Mix (WMD) Concrete and Bentonite Mix Concrete. For physical and chemical properties of both concrete mixes, cylinders were examined in the laboratory for permeability testing, scanning electronic microscopy test, slump test, compressive strength test, and split tensile test. Cylinders were prepared in the ratio 1:2:4 with varying marble dust and bentonite content with 5% increment up to 20%. At 28 days with 10% replacement of marble dust and bentonite with cement, the permeability of WMD and Bentonite concrete were decreased by 21% and 34%. Increasing the percentage of WMD and bentonite from 10 to 20%, the MD concrete permeability was drastically increased. After crossing 10% limit it starts working as over burdening additives and allows water to flow through the cylinders, while with bentonite mix concrete by 20% replacement with cement, the permeability was further decreased up to 43%. The compressive and split strength test results of both mixes were totally different from each other. The compressive strength of WMD mix concrete decreased as the percentage of WMD was increased. At 28 days with 10% replacement, the compressive and split tensile strength were reduced by 8.9% and 2.1%. Whereas in bentonite mix, the concrete compressive and split strength were increased by 7.2% and 1.45 and were furthermore increased up to 20% replacement.
DOI: 10.12755/isec.res.2018.97
title: Experimental Study of Innovative Composite Buckling-Restrained Fuse for Concentrically Braced Frames Under Cyclic Load

description: Concentrically Braced Frames (CBFs) are among the most commonly used lateral resisting systems utilized in the construction of steel structures due to their rigidity, low lateral displacement and ease of implementation. However, the lack of ductility due to the buckling that occurs in the bracing elements before yielding is their main disadvantage. This study presents an innovative Composite Buckling Restrained Fuse (CBRF) to be used as a bracing segment in concentrically braced frames that improves the ductility and eliminates premature buckling. The proposed CBRF with relatively small dimensions is a hysteretic damper consisting of thin steel plate core and extra tensile elements embedded in a composite encasement. Two CBRF samples are designed and tested experimentally. The results indicate that the proposed structural fuse has a ductile behaviour with high energy absorption and sufficient strength along with a reasonably stable hysteretic response under cyclic load.
DOI: 10.12755/isec.res.2018.98
title: Experimental study on compressive Young's moduli and tensile Young's modulus of Fly Ash concrete

description: Initial cracks due to volume changes at an early age affect the durability of concrete structures, so numerical simulations are often conducted in order to predict cracks. Such prediction requires some mechanical properties of early age concrete. Tensile Young's modulus is directly dependent on the prediction of tensile stress and is one of the important input data for FEM analysis. However, direct tension test for tensile Young's modulus needs a unique apparatus and specimen, and such test is not suitable for evaluating Young's modulus at early ages of concrete. The present study compared tensile Young's modulus with compressive Young's moduli of Fly ash concrete. Compressive Young's moduli used in this study were secant modulus and initial tangent modulus. In addition, linear modulus taken from a regression line of a compressive stress-strain curve in the range of stresses less than the splitting tensile strength was also evaluated. It is found that the secant modulus, which is generally used as Young's modulus in Japan was clearly smaller than the tensile Young's modulus, which means that, tensile stresses evaluated using a secant modulus might be underestimated. On the other hand, linear modulus and initial tangent modulus were almost equal to the tensile Young's modulus. This result indicates that tensile stresses can be evaluated using Young's modulus obtained from a compression test with general apparatus and specimens.
DOI: 10.12755/isec.res.2018.99
title: EXPLANATION OF CONCRETE FILLING DEFECT ON MORTAR LOSS MODEL

description: Problems with filling can lead to rebar corrosion and impair the durability and all other functional aspects of reinforced concrete structures. However, the prevention of concrete filling defects is left to the skill, judgment, and experience of on-site operators. In this research, we develop a methodology for quantitatively estimating the rate of occurrence of concrete filling defects. By this, we hope to promote the efficient and effective prevention of such defects at construction sites. Therefore, as a model for defective filling, we propose a mortar loss model in which the mortar component of concrete free falling into the frame adheres to the reinforcing bars in the frame, and based on that, we conducted an experiment. Using actual measurement data, we quantitatively estimated the risk of defective filling.
DOI: 10.12755/isec.res.2018.100
title: FLEXURAL STRENGTH OF SQUARE CFT BEAMCOLUMNS WHEN DAMAGED WITH CONCRETE CRACKS

description: The lateral stiffness of CFT beam-columns is considered to decrease because of the damage by the concrete crack or yielding of the materials however the relationship between two phenomena is not clear. It is necessary to clarify the strength when the CFT columns damaged by the concrete crack for evaluating the lateral stiffness of CFT beam-columns properly. The purposes of this study are to calculate the flexural crack strength of a square CFT section and to compare them with the yield strength. The analysis is carried out as follows
description: 1) assuming the stress-strain relationships of materials and the strain and stress distribution of the cross-section, 2) setting the limit of the tensile strain of concrete and 3) calculating the relation between the axial force and the bending moment when the strain of concrete reaches the limit tensile strain. Parameters are width-thickness ratio, the yield strength of a steel tube and compressive strength of concrete. As a result of the analysis, we showed that the axial force ratio is 0.2 ~0.3 when the flexural crack strength and the yield strength are the same. It is concluded that the lateral stiffness decreases because of the crack of concrete and not from the yielding of materials -- when the axial force ratio is smaller than 0.2~0.3.
DOI: 10.12755/isec.res.2018.101
title: Ground Strengthening Method by Multistage Local Consolidation

description: Authors are investigating a ground strengthening method, which effectively consolidates the construction area of requisite minimum in a short time by local consolidation for the soft ground. In this paper, Authors research that the effect of increasing the strength of soft ground by using the three-dimensional elasto-plastic finite element analysis when the area of local loading is gradually changed. First, it was found that the strength of the soft ground just below the local loading surface increased with a short time by the local consolidation and ultimate bearing capacity increases to 2.6 times as much as the initial bearing capacity by the multistage loading. Next, analysis was carried out in the case of the multistage loading with cyclic loading. In the reloading process, loading area is reduced to 1/3 and 1/6 of the loading area of the previous stage. In this case, the ultimate bearing capacity increases to 8.25 times as much as the initial bearing capacity. In conclusion, it was found that the strength of the soft ground just under the loading surface is considerably increased by multistage local loading with reducing the loading area.
DOI: 10.12755/isec.res.2018.102
title: HISTORIC BUILDINGS: COMPARISONS OF PATHOLOGIES AND INTERVENTIONS: EXAMPLES OF REUSE

description: In the recent years, many Gulf States have emerged because of their significant urban growth to contemporary architecture. In the same time, the growing number of conservation projects shows the raising need to enforce appreciation of the architectural heritage, to enhance and regenerate the historical memory of the counties. This paper offers a comparison between some recent conservative projects in Qatar conducted to some significant residential religious and commercial buildings, analyzing the pathologies that affected the structures, the reasons of deterioration before the restorative interventions, the comparison of methods and techniques that were adopted during the works and the proposals for reuse. Analyses of the data have permitted to classify the building pathologies and the conducted interventions and could be applied to other conservation projects in the future.
DOI: 10.12755/isec.res.2018.103
title: HYSTERESIS CHARATERISTICS OF SQUARE CFT COLUMNS SUBJECTED TO AXIAL FORCE AND BENDING MOMENT

description: Hysteresis characteristics of concrete filled steel tubular columns have been proposed. However, it has not been clarified if the skeleton curve could be applied for slender columns, and there are few studies about the unloading stiffness of the hysteresis loop. The purpose of this study is to compare the skeleton curves of square CFT columns, which have been proposed by the moment-rotation angle relationships and the experimental data by the previous research. The relationship between the initial stiffness obtained by the theoretical calculation and the unloading stiffness obtained by the experimental study are shown. Also the effects of the axial force ratio and the width-thickness ratio on the above mentioned relationships are discussed. The loading condition of the experimental study is monotonic and cyclic loading. It is found that the skeleton curve evaluates conservatively the bending moment-rotation angle relationships obtained by the test in both loading conditions, except for the widththickness ratio 43 specimen with cyclic loading. The ratio of unloading stiffness exKr obtained from the experimental data and calculated theoretical stiffness K was shown. The effect of the axial force ratio on the exKr/K was observed when the rotation chord angle was more than 1% and the width-thickness ratio increased as exKr/K decreased.
DOI: 10.12755/isec.res.2018.104
title: Impression Evaluation Of Concrete Surface Using ByProducts

description: Cement concrete requires strength, durability, and workability. Furthermore, the appearance of concrete must be good. Recently, the concrete industry has a tendency to actively utilize by-products, all over the world. But, consumers dislike the color of concrete using by-products. This is an obstacle to the active use of by-products. However, it is not clearly understood how consumers make the impression to color of concrete using byproducts. Therefore, we conducted a questionnaire survey using concrete using byproducts, and analyzed the answers with factor analysis and covariance analysis. As a result, the following was clarified: (1) three factors, such as beauty, massiveness and familiarity, were extracted as a factor of exposed concrete appearance, (2) the beauty of concrete was enhanced by the whiteness of the surface and was worsened by pits and surface yellowing, (3) the massiveness of concrete was worsened by the beauty and surface whiteness, and (4) even though the subjects knew that recycled byproducts were used in concrete, the evaluation of beauty did not change.
DOI: 10.12755/isec.res.2018.105
title: Influence of initial Deflections on Coupled Buckling Strength of Unstiffened Square Box Section Columns

description: Although it is well known that initial deflections have a significant influence on coupled buckling strength, their quantitative influence is not clear. In this paper, a series of nonlinear finite element analyses to reveal the quantitative influence of initial deflections on coupled buckling strength are conducted with MSC.Marc. There are nine kinds of combinations about the size of local and overall initial deflections including 1/75, 1/150, 1/450 of the plate width and 1/500, 1/1000, 1/3000 of the column length. In addition, the width-thickness ratio and slenderness ratio parameters are also varied in the parametrical study. Both ranges of slenderness and the widththickness ratio parameters are from 0.1 to 2.1. As a result, the initial deflection influence coefficient is proposed to describe the quantitative influence of local and overall initial deflections on coupled buckling strength. The numerical results reveal that the coefficient decreases with the increase of initial deflections. The sensitivity of the strength to initial deflections depends on both width-thickness and slenderness ratio parameters. The maximum decrease of 21.4% on load-bearing capacity caused by local initial deflection appears when width-thickness and slenderness ratio parameters equal to 1.2 and 2.1, respectively. Column strength is quite sensitive to overall initial deflection at the slenderness ratio parameter equal to 1.4. The maximum decrease in load-bearing capacity reaches 18.2%.
DOI: 10.12755/isec.res.2018.106
title: Influence of Sand Percentage to Fresh Concrete Properties

description: In recent years, the target value of slump in general concrete construction is changed from 8 cm to 12 cm in Japan so that constructors will aim to improve workability and ensure quality. However, increasing the concrete slump may cause material separation. As one of the evaluation methods of material separation of fresh concrete, although TAISEI CORPORATION developed a "T-post slump test," this test result depends on the engineers' experience because this test is the qualitative evaluation, not the quantitative evaluation. Therefore, in order to propose the simple evaluation method of this test, we investigate the relationship between the result of the T-post slump test and bleeding amount of fresh concrete in each sand percentage. As a result, it shows that the material separation, which water exudes on the surface, in the T-post slump test occurs at the sand percentage of 40.0% and 50.0% and the final bleeding amount also obtains 0.39 cm3 /cm2 and 0.53 cm3 /cm2 .
DOI: 10.12755/isec.res.2018.107
title: Investigation of Temperature Rising Mechanism in Long Tunnel by Numerical Simulation

description: Abnormally high temperature inside the long, undergrounded tunnel is a problem in the urban area. As one of the countermeasures, a ventilation fan has been operated. However, the insufficient temperature reduction effect and high cost are an issue and improvement is required. In this study, in order to improve the operating plan of ventilation, the flow field and temperature distribution characteristics are clarified by computational thermal fluid analysis, and the operation of the optimum ventilation was decided. The dominant factors for the temperature rising were identified as traffic volume, lane axis wind speed, cross flow ventilation, and heat flux between tunnel body and air in tunnel. In the analysis, we focused on these four factors, and applied these factors obtained from long-term on-site measurement to the boundary condition and the initial condition. In addition, the amount of heat from vehicle traffic was calculated based on the measurement and the past report results. The analytical model is 1000 m partial tunnel section where the temperature rising was intense. The validation of numerical model was verified from the comparison between the analysis results and the measured values. It was confirmed that the effect of increasing lane axis wind speed as a countermeasure was not significant, and the ventilation amount of crosswind is recommended as 60 m3 /s.