27 Articles Published

1. MECHANICAL CHARACTERISTICS OF DUAL-PHASE STEEL B500C AFTER SHOT PEENING PROCESS

Authors: AR.DRAKAKAKI, , CH.APOSTOLOPOULOS , K.KOULOURIS

Abstract: During the last decades, many durability problems have been recorded on reinforced concrete (RC) structures, which are located in coastal areas. Chloride corrosion is among the various degradation mechanisms of steel reinforcement which lead to the premature deterioration of RC structures. In this paper, an effort was carried out to increase the corrosion resistance of high ductility dual-phase steel (B500c), without any interference in the chemical composition or in the production mode, but through shot peening process. More specifically, shot peening treatment was used on the one hand in order to clean the surfaces of the steel bars and to remove the “impurities” that act as underlying destructive cores on them, and on the other hand, in order to create surface compressive stresses. The whole process was carried out according to the pertinent protocols, with the use of olivine pellets. Subsequently, the corrosion resistance behavior of the steel was experimentally examined, both with

Keywords: corrosion, mechanical performance, shot peening, pits

Pages: 93 - 99 | DOI: 10.15224/978-1-63248-079-8-102

2. THE EFFECTS OF VISCOUS BULK COMPRESSIBILITY FOR NONCYLINDRICAL HELICES

Authors: HAKAN ARGESO , MEHMET H. OMURTAG , NIHAL ERATLI

Abstract: In this study, the effects of viscous bulk compressibility on the dynamic viscoelastic response of noncylindrical helicoidal rods are examined. For this aim, a viscoelastic model is proposed that takes standard type of distortional behavior and Kelvin type of bulk compressibility. Based on Timoshenko beam theory, two-nodded curvilinear elements are in Laplace space. The viscoelastic material properties are implemented into the formulation through the use of the correspondence principle (elastic-viscoelastic analogy). The analysis is carried out in the Laplace space and the results are transformed back to time space numerically by using the modified Durbin's algorithm. As sample problems, the noncylindrical helicoidal rods fixed from both ends which are subjected to dynamic step type of distributed loading are considered. Three different helicoidal rods that have different helical geometries are analyzed and their dynamic responses are compared. The effects of viscous bulk compressibili

Keywords: viscoelasticity, noncylindrical helicoidal rod, mixed finite element method, Laplace space

Pages: 1 - 5 | DOI: 10.15224/978-1-63248-042-2-01

3. INVESTIGATION OF LEARNING CURVE EFFECT ON GAS PIPELINE CONSTRUCTION IN EGYPT

Authors: MOHAMMAD A. AMMAR , MOHAMMAD SAMY

Abstract: Learning development effect plays an important role in planning and scheduling of repetitive projects. Several mathematical models, or learning curves, have been proposed to investigate improvement in productivity as a function of the number of units produced. Deciding the best-fit learning curve model for the activity under consideration is a management challenge. In this paper, the best-fit learning curve model for describing past performance of gas pipeline construction in Egypt is presented. Data were collected from real-life projects that are constructed in different types of land and having different size, length, pipe diameter and under various weather conditions. Only welding activity is considered in the present work because it is a labourintensive activity. Cumulative average data is used to represent collected data, which gives a smooth curve as well as avoids scattered data. The commercial Statistical Package for Social Science (SPSS) is used to calculate Pearson's coeffici

Keywords: Repetitive Projects, Gas Pipeline Construction, Learning Development Effect, Learning Curve Models, Cumulative Average Data.

Pages: 6 - 10 | DOI: 10.15224/978-1-63248-042-2-02

4. DETERMINATION OF AN EMPIRICAL MODEL FOR CALCULATING THE STRAIN OF A DAM IN TERMS OF HYDROSTATIC THRUST

Authors: FELIPE PINA GARCIA , RAUL PEREDA GARCIA , JULIO MANUEL DE LUIS RUIZ , RUBEN PEREZ ALVAREZ

Abstract: The deformational control of structures has its greatest exponent in the control of large dams, which depending on structural typology, can be subjected to movement generally based on the pressure that it suffers. The designer usually calculates the theoretical displacements that the dam must suffer depending on the hydrostatic pressure, function of the thrust bearing, but it is also true that this calculation is theoretical and it is not usually adjusted to the real movements, due to the uncertainties that arise in the construction of any dam and make the original project have more or less significant changes in the final construction. In favour of the builder, it must be said that the actual displacements are usually lower than the theoretical ones. The present research focuses on the determination of an empirical model that allows calculating the deformation based on practical observations of a direct pendulum over 14 years, which determines the displacement and the pressure experie

Keywords: Auscultation, geometric control, pendulum, hydrostatic thrust.

Pages: 11 - 15 | DOI: 10.15224/978-1-63248-042-2-03

5. DEVELOPMENT OF CONTROLLER PROGRAM FOR ADMINISTERING TRIAXIAL TEST PHASES BY COMPUTER COMMANDS

Authors: TANAY KARADEMIR

Abstract: The triaxial testing is one of the most common and theoretically sound methods to determine the stress-strainstrength characteristics of soils in the laboratory. The primary function of a triaxial testing system is to apply a threedimensional axisymmetric state of stress in terms of imposed axial and radial stresses as well as longitudinal deformations on a cylindrical soil specimen through all-around chamber fluid pressure and axial load mechanism, respectively. As such, the determination of stress-strength-strain properties of soils through laboratory measurements requires conducting high quality triaxial tests. In this regard, a programming code with userfriendly interfaces for running sophisticated triaxial testing procedures including initial saturation, consolidation and shearing test phases was developed. The created controller software is capable of performing the necessary triaxial test phases including test apparatus set-up, saturation, consolidation and shear testing. As suc

Keywords: Triaxial Testing Procedures, Controller Software, Triaxial Test Phases, Computer Control Programming Code, User-friendly Interface

Pages: 16 - 20 | DOI: 10.15224/978-1-63248-042-2-04

6. BUILDING STOCK REFURBISHEMENT IN ROMANIA. A CASE STUDY IN BUCHAREST.

Authors: CATALIN TEODOSIU\ , RALUCA TEODOSIU

Abstract: The energy consumption of buildings is responsible for 40% of total EU energy consumption and is the main source for greenhouse gas emissions (about 36% of the EU’s total CO2 emissions). In this context, refurbishment of the existing building stock represents one of the main solutions in order to improve the energy efficiency in the building sector. Consequently, the aim of this study is to present data in this field, based on a case study for a block of flats in Bucharest (Romania). Heating energy consumptions are compared, before and after thermal rehabilitation interventions. The computations are performed based on the Romanian calculation methodology concerning Building Energy Performance, using standard and measured climatic data. It is worthwhile to mention that the results are compared to measured heating energy consumptions for several heating seasons.

Keywords: rehabilitation of buildings, heating energy consumption, reduction of CO2 emissions

Pages: 21 - 24 | DOI: 10.15224/978-1-63248-042-2-05

7. STUDY OF THE CONFINEMENT CONTRIBUTION ON THE MECHANICAL BEHAVIOR OF COMPOSITE STRUCTURES MADE WITH CONFINED GROUND FOR USE IN CIVIL AND/OR GEOTECHNICAL ENGINEERING.

Authors: ALLICH M , BENOUALI A , CHERIFI A , MENAA L , ZIRARI M

Abstract: Confining of granular materials remains a very interesting engineering practice to perform civil and / or geotechnical engineering works. In this paper, the analysis of the mechanical behavior of technical fabric- confined sand models in order to design bearing provisional and / or permanent structures is exposed. A composite structure, made of local materials (technical fabric and sand) and exposed in previously achieved works, belongs to a context of sustainable development, when a design and an analysis, for the first time, of a monostory building for use in inaccessible areas were carried out (i.e. Sahara). As a new perspective, many other applications (geotechnical) are considered, such as retaining wall structures, structures for protection against impacts and linear structures applied in rural road traffics. For this purpose, an experimental analysis was conducted on specimens made of technical fabric-confined sand in order to determine the mechanical properties of studied struc

Keywords: sustainability, bearing capacity, protection, structure, technical fabric, confined sand.

Pages: 25 - 30 | DOI: 10.15224/978-1-63248-042-2-06

8. BOND EFFICIENCY FACTOR AT DIFFERENT TEXTILE GEOMETRIES REINFORCED CONCRETE BEAMS

Authors: FAHED ALRSHOUDI , PHILIP PURNELL

Abstract: Textile reinforced non-structural concrete member has been commonplace in last decade in such application such as façade. The mutli-advantages of textile reinforcement have attracted the researchers to investigate applying this material in the role of a main reinforcement. Because of this, the cover thickness could be theoretically reduced due to the textile resistance to the corrosion. However, there are some impediments need to be studied. The interaction between the matrix and textile reinforcement which is represented by the bond efficiency factor of textile is one of the areas that needs to be fully understood. The impact of bond on the behaviour of textile reinforced concrete beams is notable. Therefore, this study investigated experimentally the effect of using different textile reinforcement geometries on the bond efficiency factor. Ten beams reinforced by different textile geometries were investigated. Four bending test was carried out. The results show that the average bond e

Keywords: Textile reinforcement, TRC, Beam, Bond efficiency factor, Textile geometry

Pages: 31 - 35 | DOI: 10.15224/978-1-63248-042-2-07

9. ASSESSMENT OF EFFICIENCY OF AIR ABRASIVE CLEANING ON MASONRY STONES AND BRICKS USING GREYSCALE IMAGING ANALYSIS

Authors: BINSHENG ZHANG , HUMAYUN REZA , NAREN GUPTA

Abstract: Advanced greyscale imaging analysis was conducted using Adobe Photoshop 6 on the surfaces of masonry stones and clay bricks, taken from old buildings, to accurately assess the efficiency of building cleaning. Five commonly used masonry stones and clay bricks for those buildings were selected, and seven abrasives were adopted for air abrasive (sandblasting) cleaning. Also the reductions in thickness were continuously monitored for assessing the cleaning efficiency. The cleaning degree at different stages was assessed using greyscale image photos, converted from original colour ones, together with reductions in thickness. In general, greyscale continuously increased with the cleaning time and tended to be stable when the surface became fully cleaned. Thickness reduction monotonically increased with the cleaning time. The most efficient building cleaning case would be the one with the shortest cleaning time and smallest thickness reduction. The harder abrasives with smaller particles size

Keywords: historic building, masonry stones and bricks, air abrasive cleaning, greyscale, cleanness

Pages: 36 - 44 | DOI: 10.15224/978-1-63248-042-2-08

10. RESISTANCE OF RECTANGULAR CONCRETE-FILLED TUBULAR SECTIONS TO THE COMBINED AXIAL COMPRESSION AND BENDING

Authors: IN KYU JEONG , SUNG WOONG PARK , YOUNG BONG KWON

Abstract: This paper describes the development of the direct strength method (DSM) for concrete-filled tubular (CFT) sections. A formula for strength interactions of CFT members under combined compression and flexure is proposed and is compared with test results. The comparison confirmed that the formula for axial and flexural strength and that for strength interactions can conservatively predict the resistance of CFT columns to the axial load and combined compression and bending.

Keywords: Rectangular Concrete-Filled Tubular (CFT) Sections, Resistance, Combined Compression and Axial Bending, Direct Strength Method (DSM)

Pages: 45 - 49 | DOI: 10.15224/978-1-63248-042-2-09

11. DEFINITION OF ONE EMPIRICAL MODEL SO AS TO REVIEW SAFETY FACTORS USED IN STRUCTURAL DESIGN AND ANALYSIS

Authors: FELIPE PINA GARCIA , RAUL PEREDA GARCIA , JULIO MANUEL DE LUIS RUIZ

Abstract: In the design phase structures generally are designed according to their strength capacity and should ensure proper service during its lifetime. The structural calculation is made from a certain material and considering loads and overloads. Due to the uncertainties in the construction processes and even when the necessary tests are performed, it is necessary to use safety factors that enable encompass the effect of these "imponderables". In the case of bridges and viaducts, before being put into service, is mandatory to check the correct operation of the structure from the "load tests". In them, especially in static load tests, vertical displacements of significant points of the structure are compared. In this way, the vertical displacements measured are compared with those obtained with the structural analysis are compared; and recovery of its original geometry. The present research focuses on the comparison of both results of load tests in different structures for a statistical study

Keywords: structural monitoring, geometric control, load tests, geometric leveling.

Pages: 50 - 54 | DOI: 10.15224/978-1-63248-042-2-10

12. EXPERIMENTAL AND NUMERICAL MODELING OF FLOW OVER A SPILLWAY

Authors: M. SALIH KIRKGOZ , M. SAMI AKOZ , N. GOKSU SOYDAN , OGUZ SIMSEK, VEYSEL GUMUS

Abstract: The measured velocity field and free surface profile of flow for two different discharges over a spillway model are used for validation purpose of the two-dimensional computational results of the same flow cases. The governing equations of the spillway flows are numerically solved using Finite Volume Method. The turbulence closure models; Standard k-, Renormalization Group k-, Realizable k-, Modified k-, Shear Stress Transport and Reynolds Stress Model are used in the numerical simulation and the flow profiles are computed using Volume of Fluid (VOF) method. The testing of the numerical results for grid-independent numerical solution is carried out using a GCI analysis. The comparisons of the computed and experimental results for both cases show that the numerical results from the Realizable k-ε model is more successful in predicting the velocity field and free surface of the spillway flow

Keywords: Spillway, Numerical solution, Turbulence models, Finite Volume Method, VOF

Pages: 55 - 59 | DOI: 10.15224/978-1-63248-042-2-11

13. ANALYSIS OF BUILDING PERFORMANCE OF AN EFFICIENT HOUSE WORKING WITH GROUND SOURCE HEAT PUMP

Authors: CRISTIAN MARACINEANU , SMARANDA MARIA BICA

Abstract: The present work analyze the efficiency of using ground source heat pump for inner space heating/cooling and hot water production in new energy-efficient buildings in Romania. Such analysis would be a way to answer to the problems resulting from the continuous increase of energy consumption. The present study describes the building performance of a 2010 construction from Timisoara, designed as an energy-efficient house. The energy consumption of this project was followed for 4 years and a new improvement is planned to be implemented.

Keywords: sustainable, energy efficiency, green technologies, pilot project.

Pages: 60 - 64 | DOI: 10.15224/978-1-63248-042-2-12

14. STABILITY OF CANTILEVER RIGID RETAINING WALLS BACKFILLED WITH SAND-GEOFOAM BEADS MIXTURE

Authors: MOHAMMAD REZA ARVIN , SAIEDEH BAGHANIAN

Abstract: This paper studies the effects of using sandgeofoam beads mixture as the backfill of cantilever rigid retaining walls on the factor of safeties against possible modes of failure. With this regard, concrete walls with specified geometrical properties are assumed and backfill material properties are extracted from a previously achieved research work. Factor of safeties against failure modes including transitional, overturning and deep-seated for different heights of wall and geofoam-sand mass ratio were obtained. Results show that unlike gravity rigid retaining walls backfilled with the sandgeofoam beads, cantilever walls don’t follow a steadily increasing trend in two of the failure mode’s factor of safeties.

Keywords: rigid contilever retaining wall, sand-geofoam beed mixture, stability, factor of safety

Pages: 65 - 69 | DOI: 10.15224/978-1-63248-042-2-13

15. A MODEL FOR THE REUSE OF DISUSED TANNERIES A CASE-STUDY FOR THE DEFINITION OF THE INTERVENTION CRITERIA

Authors: DONNARUMMA GIUSEPPE , FIORE PIERFRANCESCO , SICIGNANO ENRICO

Abstract: The regeneration of abandoned buildings and industrial areas is extremely topical due to its significant effects on socio-economic issues, urban planning and environmental protection. This contribution presents a model for the reuse of abandoned tanneries. The model considers issues regarding the buildings and their urban environment based on an integrated multidisciplinary approach. In particular, the study is divided into the following phases: compatibility between the choices and urban policies; analysis of the potential conversion of the tannery; assessment of compliance with technical standards (structural safety, fire safety, elimination of architectural barriers, energy efficiency); definition of intervention criteria. The tannery district of the City of Solofra in the Campania region of Italy was chosen to calculate the parameters of the model.

Keywords: Reuse, regeneration, abandoned tanneries, intervention criteria.

Pages: 70 - 77 | DOI: 10.15224/978-1-63248-042-2-60

16. DIRECT DISPLACEMENT BASED DESIGN (BASED ON PRIESTLEY AND KOWALSKY) VERSUS FORCE BASED DESIGN FOR WALL STRUCTURES

Authors: SICIGNANO ENRICO , NASER KABASHI

Abstract: A seismic design procedure is developed to enable design of concrete wall buildings in order to achieve a specified acceptable level of damages under the designed earthquake. The practice shows the simplicity of procedures based on direct displacement based design method in comparison with force-based design method. In order to explain the differences between these two methods we demonstrated their application in wall buildings of four, eight and twelve multi storey buildings. The results obtained are showing significant differences, thus we recommended one of these two methods.

Keywords: Direct Displacement Based Design, Force Based Design, yield displacements, ductility, RC Walls, limit states.

Pages: 78 - 82 | DOI: 10.15224/978-1-63248-042-2-94

17. METHOD N2 – ACCORDING TO FAJFAR

Authors: ARTON DAUTAJ , HAJDAR SADIKU , NASER KABASHI

Abstract: A relatively simple nonlinear method for the seismic performance evaluation of structures (the N2 method) is presented. The method combines the nonlinear static (pushover) analysis and the response spectrum approach. The method yields results of reasonable accuracy if the structure oscillates predominantly in the first mode. In the paper the method is formulated in the acceleration – displacement format. This versions combine the advantages of the visual representation of CSM developed by Freeman. By reversing the analysis process, the method can be used as a tool for the implementation of the direct displacement-based design approach.

Keywords: ”Pushover analysis”, performance evaluation, inelastic behavior, ductility

Pages: 83 - 89 | DOI: 10.15224/978-1-63248-042-2-95

18. COMPARISON OF DEFLECTION FOR BEAMS OF SELF- COMPACTED CONCRETE (SCC) AND CONVENTIONAL CONCRETE FOR PERIOD T= 40 DAYS

Authors: HAJDAR SADIKU , HAJDAR SADIKU

Abstract: Development trends for high rise Building or structures, modern skyscrapers request the different workability of fresh concrete to cast in properly way and to achieve the requested results. The many of factors such are: highest of the cast concrete, sections of concrete elements, request the concrete with more plasticity and higher class of consistency, the smaller size of aggregate, the compacted process, etc. The fulfilling the previous condition, using the Self Compacted Concrete is one of the aims in this paper. Considering this fact, researches for deflections, mechanical characteristics of concrete and strains have been conducted worldwide. In this line, we conducted an experimental research to determine the deflections on beams of self-compacted concrete and compared it with conventional concrete. The experimentallyobtained results will be presented for both types of concrete for: module of elasticity and deflections tests for duration testing time t=40 days.

Keywords: Self-Compacting Concrete, Conventional Concrete, deflections, modulus of elasticity, etc

Pages: 90 - 93 | DOI: 10.15224/978-1-63248-042-2-96

19. SIGNIFICANCE OF LIFE-CYCLE COSTING FOR SELECTION OF BUILDING CONSTRUCTION MATERIALS

Authors: ABDULAZIZ AL-GHONAMY , M. ESAM SHAAWAT , MOHAMED AICHOUNI , MOHAMMED ABDULWAHAB , NOMAN ASHRAF , OTHMAN SUBHI ALSHAMRANI

Abstract: The construction industry is one of the ever growing and leading sectors, which contributes to the economic growth of any nation. One of the current challenges in this industry is to ensure compliance with the norms and standards pertaining to the construction process, building quality, performance, and most remarkably, the environmental impact. The materials used in construction have a crucial role in meeting the above requirements, and in line with this, substantial researches are in progress, in implementing scientific techniques for the selection of construction materials. Material selection is often influenced by budget constraints, local availability, and lack of technical expertise/advice. Some materials that are attractive in terms of initial cost, can have adverse effects on quality, reliability and performance, and even a catastrophic impact on the environment, during the life span of the building. So the present article tries to convince the importance of selecting material

Keywords: Life cycle cost, Selection of material, construction

Pages: 94 - 98 | DOI: 10.15224/978-1-63248-042-2-97

20. A STUDY ON APPLICATION OF HEALING PERFORMANCE OF SILICA SAND

Authors: HONG GI. KIM , JAE SEOK. RYOU , SANG WON. HA , YONG SOO. LEE

Abstract: The experiment, which is to evaluate crackfilling efficiency by self-healing when cracks occur by the external impact and internal stress, was conducted in this study. The crack-filling can be achieved by silica sand, which was applied self-healing ingredient. Therefore, recovery of crack was evaluated because it was verified feasible of silica sand, which was applied self-healing ingredient. As a result, when self-healing ingredient of silica sand surface reacts with water, it was verified that recovery of crack was achieved via silica sand, which was applied self-healing ingredient. Based on the results, it may be applied construction structure after various durability tests and analysis. Also, the repair mortar may be applied.

Keywords: ; self-healing, silica sand, coating, water soluble film, mineral materials

Pages: 99 - 104 | DOI: 10.15224/978-1-63248-042-2-98

21. INTEGRATING BUILDING PLANNING AND DESIGN PROCESS CREATING SYNERGY BETWEEN BUILDING’S STRUCTURE, MATERIALS AND FORM

Authors: DZENANA BIJEDIC , RADA CAHTAREVIC , SENAIDA HALILOVIC

Abstract: This paper elaborates on the evolution of architectural form, building materials and structural solutions in the building planning and design process (BPDP), which is heavily conditioned by science and the level of technological advances, as well as by the roles of the key players (designers and engineers) in that process. The goal of conducted analysis is to, based on the values of traditional and conventional approach to building planning and design, come up with such system of designed/built environment, which will not jeopardize the complex system of a given/natural environment. By comparing the traditional (comprehensive, masterful work) and conventional (fragmented, specialized) approach to BPDP, it could be concluded that what is good in the old one is its holistic, integrated nature; while the new opportunities provided by a joined development of science and technology are benefits of the current moment, i.e. conventional BPDP

Keywords: architectural form, building materials, structural solutions, complexity, holistic approach, integration

Pages: 105 - 109 | DOI: 10.15224/978-1-63248-042-2-99

22. THAUMASITE FORMATION IN A NEWLY BUILT CONCRETE STRUCTURE IN NORTHEASTERN ALGERIA

Authors: BRARA AHMED , TOULOUM NAIMA

Abstract: Severe damages such as expansion, cracking, spalling, have been observed in a public facility (communal library) recently built in the northeastern region of Algeria. Microstructural examination of the concrete samples extracted from different structural elements revealed an abundant presence of thaumasite in association with ettringite and/or gypsum. The thaumasite was found within cavities at the interfaces aggregates/cement as well as in the high dolomitic cement matrix. The deterioration of the concrete studied was attributed to the thaumasite sulphate attack (TSA) supporteess by the alkali dolomite reaction (ADR). With regard to the semi-arid nature of Algerian climate, it appears that the condition of low temperature (less than 5 ° C) required for the formation of thaumasite reported in the literature seems to be not necessarily true

Keywords: concrete, expansion, sulfate, thaumasite.

Pages: 110 - 113 | DOI: 10.15224/978-1-63248-042-2-100

23. DEVELOPMENT OF MICROSCOPIC PEDESTRIAN MODEL FOR URBAN EMERGENCY PREPAREDNESS USING PARAMICS

Authors: SANDEEP K PRUSTY , SURESHA S.N

Abstract: In this study the use of traffic simulation as a tool for evaluating various strategies and designing various signal models and also implementing pedestrian model in response of emergency situations is considered and briefed. This paper presents a traffic simulation approach for evaluating the pedestrian behaviour by developing a model which includes pedestrians in a vehicular micro-simulation model i.e. PARAMICS. This study is based on testing of the prototypes and actual signs in order to determine if they convey the desired message in the desired time. This will let the users know the usability of their signs and make them reach the desired safe destination easily. In this report, pedestrian characteristics during emergency are also studied using suitable pedestrian model (eg: Fruins pedestrian model). Application of this carfollowing algorithm demonstrated by calibrating in PARAMICS will be very useful in predicting known pedestrian speed-flow relationship. The model is developed e

Keywords: Emergency Preparedness, Car-following, Pedestrian, Microscopic Traffic Simulation, Calibration, Validation, PARAMICS

Pages: 114 - 118 | DOI: 10.15224/978-1-63248-042-2-101

24. ELABORATION AND CHARACTERIZATION OF COMPOSITE MATERIALS FOR STRUCTURES WITH HIGH THERMAL HOLDING

Authors: C. FAVOTTO , J. ROGEZ , S. ABIDI , Y. JOLIFF

Abstract: In case of fire in works of engineering, the new regulations impose to realize a passive fire protection, for their superstructures. Indeed these do not always answer the requirements imposed by circulars and thus present a danger or a risk for the users and emergency personnel. These new regulations take into account in their calculations, exposure to higher and higher temperatures with shorter times of temperature increase, and therefore more violent thermal shocks. This is the case with the curves called ISO 834 (heating of the material from room temperature to 1200 ° C at a very fast rate of temperature increase: 500 ° C in 4 minutes). New materials based on calcium sulfate hemihydrates and charges have been developed in the form of plates and screened to meet these requirements. The study by calorimetry of hydration of hydraulic binders (calcium sulfate hemihydrates, for example) and additives is made in a first time to control the drying time and the rate of porosity of the mater

Keywords: Elaboration , characterization , composite , materials , structures

Pages: 119 - 119 | DOI: 10.15224/978-1-63248-042-2-122

25. SOIL SENSIBILITY CHARACTERIZATION OF GRANULAR SOILS DUE TO SUFFUSION

Authors: ABDUL ROCHIM , DIDIER MAROT , LUC SIBILLE

Abstract: This paper studies the characterization of soil sensibility due to suffusion process by carrying out a series of one-dimensional downward seepage flow tests realized with an erodimeter. Tests were performed under controlled hydraulic gradients in sandy gravel soils. We propose the analysis based on energy induced by the seepage flow to characterize the hydraulic loading and the cumulative eroded dry mass to characterize the soil response. With this approach, the effect of hydraulic loading histories and initial fines contents to soil sensibility are presented. It is found that for given soils, erosion coefficients are different if tests are performed under different hydraulic loading histories. For given initial fines fraction contents, the sensibility may be grouped in the same classification. The lower fines content soils tend to require larger flow energy to the development of erosion. These results demonstrate that this approach is effective to characterize suffusion sensibility fo

Keywords: Erodimeter, sandy gravel, suffusion, water seepage energy

Pages: 120 - 127 | DOI: : 10.15224/978-1-63248-042-2-123

26. COMPARISON BETWEEN FUZZY RISK ASSESSMENT METHODS

Authors: A. SAMER EZELDIN , KHALED NASSAR , RANIA FAYED

Abstract: Contracting for construction services is an inherently risky venture for the owner, design agent and contractor. All of these parties are exposed to unanticipated risks, exposure to economic loss and unforeseen contract liability while performing under the contract. Project risk management, therefore, has been recognised critical for the construction industry to improve their performance and secure the success of projects. Risk assessment is the most important step in risk management. Classical methods for risk assessment are no longer accurate and effective, therefore, many papers introduced fuzzy logic as a more accurate and effective technique in risk assessment. In this paper, a comparison between two fuzzy risk assessment methods; Nieto-Morote and Ruz-Vila [1] and Kuo and Lu [2] is done using the same input parameters which are risk probability (RP), risk impact (RI) and risk discrimination (RD) to determine if these methods give the same risk ranking or not. Actually, the compari

Keywords: risk assessment, linguistics variables, fuzzy logic, fuzzy numbers, risk factor.

Pages: 133 - 140 | DOI: 10.15224/978-1-63248-042-2-142

27. SINGLE-PHASE AND TWO-PHASE PRESSURE DROPS ACROSS SUDDEN CONTRACTION IN HORIZONTAL RECTANGULAR MINICHANNEL

Authors: AGUS SANTOSO , AKIMARO KAWAHARA , DAIKI GOTO , MICHIO SADATOMI , TOMOAKI TAKEHIRA

Abstract: This paper presents experimental investigations on the effects of liquid properties on pressure drop for both single-phase and two-phase flows through sudden contraction in horizontal rectangular minichannel. In order to know the effects, water and viscoelastic liquid, namely 0.1 wt% polyacrylamide (PAM) aqueous solution are selected as the working liquid, while air as the working gas. Liquid single-phase and air-liquid twophase flow experiments were conducted at room temperature using a horizontal rectangular mini-channel with a sudden contraction. The cross-sectional dimensions of the channel with the height (H), the width (W) and the hydraulic diameter (DH) for the narrow channel are 2.79 mm, 3.09 mm and 2.94 mm, while those for the wide channel are 2.95 mm, 5.98 mm and 3.95 mm. The local pressure upstream and downstream from the contraction were measured with calibrated pressure transducer to determine the pressure drop due to the contraction. As an analysis, the resulting data on

Keywords: two-phase flow, pressure drops, rectangular minichannel, sudden contraction

Pages: 19 - 23 | DOI: 10.15224/978-1-63248-059-0-65