bluuebunny/crossref_metadata_2025 huggingface dataset:
Finite Element Analysis of Tunnelling Induced Deformation towards Pile Foundation
Authors: Mohamad Ismail Mohd Ashraf , Lim Siao Phin , Tay Wui Wenn
Published: October 2015

The demand of surface area increases rapidly in the urban areas due to the increase in populations. This leads to the shortage of surface area for development in the future. Underground development is one of the solutions to solve the problems, such as the tunnel constructed underground, to provide new spaces for the development without claiming valuable spaces on the surface. Since construction of tunnel might influence the integrity of above ground structures, it is important to evaluate the impact of tunneling towards adjacent building foundation. This paper presents the numerical analysis of pile-tunnel interaction under greenfield condition for the optimization of tunnel distance, position and size relative to pile. Parametric study concerning the pile-tunnel interaction was concluded to assess the differential stress around the tunnel, ground settlement bending moment and axial force acting on pile. Pile-tunnel interaction was found directly proportional to the tunnel diameter and inversely proportional to pile-tunnel distance. The maximum surface settlement was observed at the tunnel with diameter of 1.5 times diameter (d). The highest pile bending moment and axial forces was observed at pile-tunnel distance equal to 1d.
UHPFRC as Repair Material for Fire-Damaged Reinforced Concrete Structure – A Review
Authors: Abdullah Muhd Afiq Hizami , Mohd Zahid Mohd Zulham Affandi , Abu Bakar Badorul Hisham , Nazri Fadzli Mohamed , Ayob Afizah
Published: October 2015

Exposure of concrete to intense heat will cause deterioration of its strength and durability. Previously, the fire-damaged concrete was repaired using the shotcrete and normal concrete. Recent studies utilize fibre reinforced polymer (FRP) in repairing fire-damaged concrete. Ultra High Performance Fiber Reinforced Concrete (UHPFRC) mostly developed using fine size aggregate, cement, silica fume, super plasticizer and reinforced with steel fibre has an excellent mechanical properties compared to high strength concrete and with an addition of steel fibre in the UHPFRC enhances its ductility behaviour which is not possessed by normal concrete, hence, UHPFRC indicates a promising candidate as repair material to fire-damaged concrete. The aim of this paper is to review on the properties of UHPFRC to be utilized as repair material to fire-damaged concrete structure based on previous research on UHPFRC and fire-damaged structure.
Strength Prediction of Double-Lap Bolted Joints of Woven Fabric CFRP Composite Plates Using Hashin Formulations
Authors: Ahmad Hilton , Abed Mustafa Abbas
Published: October 2015

Failure modes in composite plates with bolted joint configuration include net-tension, shear-out and bearing failures. Few analytical and numerical approaches in strength prediction frameworks of composite plates with bolted joints were reported in the literatures. Present works are dealing with strength prediction in bearing failure of woven fabric CFRP plates with double lap bolted joint configurations by modeling 3D finite element analysis framework. The pre-processing stage is modeled using commercial ABAQUS CAE package and takes into account all parts interactions, clamping pressure and friction contact. Testing series are following the experimental works found from the literatures with variation of plate width to hole diameter (W/d) ratios and incorporated with finger-tight clamp-up. Hashin failure criterion was implemented as constitutive modeling in current analysis, based on ply-by-ply approaches found to be more appropriate phenomenon in bearing failure. The strength prediction results demonstrated good agreement with all experimental datasets particularly with bearing failures as compared with previously reported work, used stress concentration approach found to be accurate in net-tension failure only.
Adverse Effects of Soil Grouting on Sandy Soils
Authors: Akyol Erdal , Tasdelen Suat , Aydin Ali
Published: October 2015

Uncontrolled growing of construction industry in Turkey has caused a large number of buildings were constructed without the benefit of sufficient engineering supervision. These phenomena have contributed to the increase in the number of seismically weak buildings. After the Great Marmara Earthquake seismic performances of the existing structures have been inspected and some of them fortified. In this context, an existing building foundation, built on a problematic soil and located in Denizli where is in high seismic risk area, has been strengthened by cement injection. Grouting holes up to 7 m in depth from the basement level were used in 45 points. The injection has created a less permeable barrier, acts like an underground dam. This barrier has caused rising of the underground water table around the recharge area of the foundation. The raised underground water has increased hydraulic gradient and hydraulic pressure. Then, the basement floor has arched up to 12 cm and underground water has risen up to 30 cm high after one year of the injection practice. In this study, hydrogeological characteristics of the soil structural analysis have been evaluated and some solutions suggested remedying the problem. It should be kept in mind as injection practice is employed in aquifers.
Behavior of Cold Recycled Mixes in the Range of Low Temperatures – Experimental Study
Authors: Krpalek Ondrej , Valentin Jan
Published: October 2015

Cold recycled mixes are used in many parts of the world as a standardized pavement rehabilitation technique. The quality of the mixes has been so far assessed by strength characteristics, water susceptibility and stiffness. In some cases frost resistance is determined as well. Nevertheless, especially for regions with winter seasons where temperatures are reaching values below 0°C, there are no standardized procedures and sufficient findings related to resistance to cracking and fracture behavior. Experimental study done at CTU in Prague describes three types of tests performed on 15 different cold recycled mixes. In parallel three standardized hot asphalt mixes were selected and used as well for a comparison of behavior in the range of low temperatures. Finally specimens acquired from an existing construction site where cold recycled technology was applied have been cored and tested mainly for crack propagation test. In general three tests have been selected and include crack propagation text on semi-cylindrical specimens, flexural strength test and relaxation test. Behavior in low temperature range and resistance to cracking has been tested in the temperature range of 0°C to-10°C.
Effects of Wax Additive on the Rheological Properties of Asphalt Binder
Authors: Gungat Lillian , Hamzah Meor Othman , Goh Shu Wei
Published: October 2015

Environmental problems caused by high temperature during the production of asphalt and road paving prompted research on alternative material that is more environmental friendly. Recent advances in asphalt technology have allowed the reduction of construction temperature using the warm mix asphalt additives. This paper presents the laboratory results on the effects of a wax warm mix additive on the asphalt binder rheological properties. The additive were blended with conventional binder using laboratory mechanical mixer at 0, 1, 2, 3, 4 and 5% by the mass of binder. Then, the binders were tested for flow properties, stiffness and its resistance to rutting and fatigue. Tests were performed using rotational viscometer and dynamic shear rheometer on unaged and aged samples. The results show that the addition of wax warm mix additive improves the flow properties by reducing the viscosity and leads to lower construction temperature. Characterization of modified binders’ rheological properties at intermediate and high temperature indicates that the amount of wax warm mix additive addition slightly affects the binder stiffness and its resistance to rutting and fatigue. Based on the rheological test results, the 3% wax warm mix additive produce comparable rheological properties with the conventional binder. Therefore 3% wax warm mix additive is suggested to be the optimum amount for the road construction application.
Locating Problematic Road Sections: Comparisons between Crash Data and Composite Index Method
Authors: Intan Suhana M.R. , Hussain H. , Law T.H. , Ahmad Farhan M.S.
Published: October 2015

Aware on the importance of upgrading and maintaining the safety level of existing road network, several attempts on localizing problematic road areas have been made. In current practice, the identification of those problematic sections was recognized based on the road’s safety level and one of the most common and acceptable method is by using crash data of the particular road network as a starting point for further actions. However, the information provided by crash data is far from providing good and broad pictures of the factors leading to crash. These circumstances have bringing out the needs to have another road safety indicator that can extensively describes actual situations at problematic road areas as well as can be used as a basis for further maintenance works. By focusing on the environment aspect of the roads, fourteen road environment indicators were chosen based on their abilities to portrayed current road environment conditions and its potential in triggering road traffic crashes. Data of these indicators were collected by means of naturalistic driving method within 80 km length road of Federal Road 2 connecting Kuantan and Maran Town in Pahang State. Composite road environment risk index was developed using these data where combination of risk generated from these environments aspects were evaluated and used in localizing problematic road sections. Apart from that, the outcomes were also used as basis in planning for road improvement plans. The development of composite road environment risk index as a proactive method in defining poor sections has proved to be very useful in identifications of problematic road sections requiring urgent road improvement works especially when crash data is not available or in poor quality.
Volume-Delay Function in Trip Assignment
Authors: Leong Lee Vien , Tan Kwang Yew
Published: October 2015

Four-stage demand models are the most popular travel demand forecasting models. Trip assignment which is the last stage in the four-stage demand modelling is a key element in travel demand forecasting process. Traffic assignment model is used to assign travel demands into the road network and predict network flows that are associated with future planning scenarios based on the estimates of link travel times. In order to calculate travel time between origin and destination, a function presenting the relationship between link delays and link flows is used. This function is known as Volume-Delay Function (VDF) and it is the fundamental component of equilibrium trip assignment models. This study aims to investigate and improve VDFs for heterogeneous traffic at different type of arterial roads in Malaysia by using the road network in Balik Pulau, Penang as a case study. Primary data such as traffic volume and speed are collected at three types of arterial roads, which are the principal arterial, minor arterial and collectors to derive the parameters required in the VDFs. In this study, the most well-known and most widely-used volume-delay function which is known as the BPR function developed by the U.S. Bureau of Public Roads was investigated and calibrated using the transportation planning software, EMME 4.1.3. The calibrated functions are then validated with field data. The output from this research is very important as better understanding of VDFs can produce better estimate of link travel times and hence better planning for future scenarios.
The Alternative Trip Generation Model for Flat/Apartment/Condominium and Low Cost Housing Subcategories
Authors: binti Mohd Shafie Shafida Azwina , Mohd Sadullah Ahmad Farhan , Hamzah Meor Othman , Leong Lee Vien
Published: October 2015

Malaysian Trip Generation Manual (MTGM) is an important document to assist transport planners in forecasting the estimated trip attraction and trip production from a land use. The forecast is crucial in estimating trip generation from a proposed development on the existing road network. Therefore, this study is to verify the accuracy of the existing trip generation model published in MTGM for flat/apartment/condominium and low cost housing subcategories. By applying variable transformation, four alternative models were developed. They were the logarithmic model, the inverse model, the linear-logarithmic model and the logarithmic-linear model. Using residual analysis, influential data was identified and taken out for second analysis. Model selection was based on R2 value, t-test and Kolmogorov-Smirnov test results. Besides linear model, logarithmic model is also truly representing trip generation model for both subcategories. There is some difference in the trip generation estimation between the study model and the existing model in MTGM. Sensitivity analysis shows the level of sensitivity between study model and existing linear model. One of the implications in using the studied trip generation model is in evaluating level of service of the junction.
H2S Emissions within Vicinity of Swine Farming Area in Nibong Tebal, Pulau Pinang, Malaysia
Authors: bin Ab Manaf Mohd Badrul Hisyam , Ramli Nor Azam , Yahya Ahmad Shukri , Mohd Zahid Mohd Zulham Affandi , Ahmad Muhammad Munsif , Isa Nur Fitriah , Zainol Norrazman Zaiha , Azizi Azizan Muhammad , Muhammad Khairunnisa , Sofri Liyana Ahmad
Published: October 2015

Animal farming industries is important in Malaysia because its contribution to the economy. The production causes all the major environmental negative impact such as water pollution from waste water and malodours emanating from farms. The current methods of disposing of manures were no longer adequate or suitable for the new, large and intensive animal farming. Inappropriate technologies, poor maintenance and inadequate dimensions and design of the treatment systems in addition to inappropriate production method are causing serious environmental problems especially odorous emissions. Present of Hydrogen Sulphide (H2S) in the air contribute to the odour pollution. Static monitoring has been done and maximum concentration of H2S is 220.6 ppb. Temperature and relative humidity fluctuations were seem to have influence on concentration of H2S. Linear regression analysis was shown that relative humidity has higher influence on correlation gaseous pollution compared to temperature. Correlation coefficient for H2S and relative humidity was in range 0.675 to 0.881 in the morning and 0.417 to 0.729 in the evening, which are in range of strong correlations.
Development of a New Tsunami Generator
Authors: Hiraishi Tetsuya
Published: October 2015

A middle size experiental wave generator has been implemented is the Ujikawa Open Laboratory, Disaster Prevention Research Institute, Kyoto University. The generator is composed of a pistontype wave maker, a head strage water tank and a current generator to mainly reproduce long waves like tsunami and storm surge.The paper desribes severalexperimental series to predict the applicability of the generator to model tests. The three operating sysemes are capable to be controlled in one operating sysytem and start time is contorolled separately according with the target tsunami and storm surge profiles. A sharp tsunami profile is reproduced in adjusting the start timing of piston type wave maker and opening gates of head storage tunk. Any type of tsunami waves are reproduced in the generator and it becomes a strong tool to predict the effective of ”resiliency” of hardwares.
Optimization of COD and Color Removal for Matang’s Landfill Leachate Treatment by Using Polyaluminum Chloride
Authors: Ahmad Zamri Mohd Faiz Muaz , Yusoff Mohd Suffian , Abdul Aziz Hamidi , Kamaruddin Mohd Anuar
Published: October 2015

In this research, a physico-chemical treatment method of coagulation-flocculation process is implemented in treating partially stabilized leachate from Matang Landfill, Perak, Malaysia. Central composite design has been used to optimize the independent variables namely polyaluminum chloride (PAC) coagulant dosage (A), rapid mixing speed (B) and rapid mixing time (C). The experimental results were analyzed by using analysis of variance (ANOVA). The results revealed that the percentage of color and COD removal was found increased by increasing rapid mixing speed with optimum removal of 95 % and 56 % respectively. Besides, the R-squared values implied that 86.22 % and 97.34% of the total variation explained by the model equation. Furthermore, the model analysis revealed that rapid mixing speed were significant for removal of color and COD through single parameter (B) and interaction between parameter (AB) respectively. This finding proves the influence of mixing parameter in coagulation-flocculation process for leachate treatment.
Review on Applications of Nanoparticles in Landfill Leachate Treatment
Authors: Zaidi Ab Ghani , Yusoff Mohd Suffian , Andas Jeyashelly
Published: October 2015

Sanitary landfill is the most common way to eliminate solid waste. However, sanitary landfill generates large quantity of leachate. Leachate can be defined as a liquid that passes through a landfill and extracted dissolved and suspended matter. The presence of large quantity of contaminants in leachate is harmful to human and ecological environment. This can lead to health issues, including gastrointestinal illness, reproductive problems, and neurological disorders. There are several significant techniques have been made to overcome the problem of leachate pollution, including photocatalytic oxidation, adsorption/separation processing and bioremediation. However, the applications have been restricted by many factors, such as processing efficiency, operational method, energy requirements, and economic benefit. This present article provides an overview of research studies and advances concerned with the development of nanoparticles and their potential applications in leachate treatment. Nanoparticles can act as antimicrobial and function as reducing agent and catalyst in detoxification of pollutants in the environment, such as organic, inorganic and heavy metals. NPs have been suggested as efficient, cost-effective and environmental friendly alternative to existing treatment materials and presents a number of potential environmental benefits.
Effects of Substituted Transition Metals (Me:Cr3+, Mn3+, Fe3+ and Mo) on the Fe2+/Modified Silica in the Oxidative Degradation of Reactive Black 5
Authors: Nasuha Norhaslinda , Hameed B.H.
Published: October 2015

The Fe2+/modified silica catalysts have been substituted with four types of transition metals such as Fe3+, Cr3+, Mn3+ and Mo. The catalytic activity of these catalysts has been tested for the oxidative degradation of Reactive Black 5 (RB5) at 30°C and pH 4.5. The substituted Fe2+/modified silica with Fe3+ (Fe2+:Fe3+/ m-SiO2) exhibited the highest catalytic performance compared to others transition metals by degrading the RB5 nearly to 95%. This catalyst possessed on high stability by maintaining its performance during the three successive cycles of reaction. These findings can be ascribed to the plausible enhancement in the formation of hydroxyl radicals (HO●) due to the effective redox between Fe2+ and Fe3+
Optimization of HCO3- Production Reflect to CaСo3 Precipitation for Self-Healing by Bacillus sphaericus
Authors: Mokhtar Norfaniza , Mohd Ilias Zhameir Shafiq , Tajarudin Husnul Azan , Megat Johari Megat Azmi
Published: October 2015

Bacteria are able to perform metabolic activities which promote the precipitation of calcium carbonate in the form of calcite. Bacillus Sphaericus was used in this study, which is an ureolytic bacteria that can precipitate calcium carbonate in its environment by the decomposition of urea into ammonium and carbonate. The bacterial degradation of urea basically increases the pH and promotes the microbial deposition of carbonate as calcium carbonate. In this research, the capability of bacteria to influence the formation of HCO3- by the production of urease enzyme was investigated. Results of growth rate and characteristics of bacteria showed that 20g/L of urea concentration was able to provide a good environment for bacteria with sufficient amount of nutrient to survive. The formation of HCO3- was parallel with NH3 production where the formation of HCO3- increased slowly as the ammonia production decreased. Urea degradation with suitable concentration of urea by 20g/L may form high HCO3- compared to 25g/L urea concentration. The results from the experimental works indicated that the optimal urea concentration was 20g/L.
Riverbank Filtration Site Suitability Selection Using Spatial Data Techniques: Case Study for Kota Lama Kiri, Kuala Kangsar
Authors: Abdul Razak Mohd Firdaus , Md Said Md Azlin , Yusoh Rais
Published: October 2015

Site surface characterization is an important factor to identify a suitable area for riverbank filtration (RBF) location. However, selecting the suitable area for RBF location using conventional methods is costly and time consuming, usually restricted to a small area. In this research, a site suitability for RBF location methodology was proposed using spatial data techniques to determine the site suitability of the potential RBF location in Kota Lama Kiri, Kuala Kangsar study area. A high resolution GeoEye-1 satellite imagery acquired in 2012 was classified using the supervised classification process for land cover. The classified image was further analyze using overlaying, buffering and Boolean analysis, to identify the suitable site for RBF based on location, distance from the river and distant from built-up area. In addition, the geology and hydrological data were extracted from published maps, which were then converted and integrated into GIS spatial database. The results show that the classified GeoEye-1 image produces the overall accuracies of 83.50% % with kappa statistic value of 0.806. The site suitability map for the potential RBF locations in the study area were produced confirms the location of an existing RBF well developed by Lembaga Air Perak (LAP). The methodology can be readily used to provide information of suitability area for RBF location in which can be used by water supply management to locate the RBF well for extraction purposes.
Modelling Critical Period of a Reservoir System Using Performance Indices in Johor Catchment
Authors: Saket Oskoui Issa , Abdullah Rozi , Montaseri Majid
Published: October 2015

Modeling the duration of the critical period (CP) and hence the precise mode of behavior of a reservoir system prior to analysis is advantageous because then the input data interval can be selected to match the requirement. In this sense, over-year systems (CP > 1 year) can be adequately analyzed using annual time-series data, whereas for within-year systems (CP < 1 year), only the critical 12 months in the data record are needed to be considered. The current standard demand parameter method for prediction of the behavior of reservoirs is based only on demand and coefficient of variation of annual flows. However, performance measures such as reliability and vulnerability are also important in the critical period of reservoir systems. Hence, the objective of this study, is to develop a predictive relationship for critical period involving standard demand parameter and both reliability and vulnerability performance indices as for use during the reservoir planning stage. The Johor catchment was selected as the case study. The reservoir was analyzed using a Monte Carlo simulation technique by modified SPA. The critical period prediction model was then calibrated based on the simulation results. Subsequently, the performance of the model was observed by comparing the model’s results with simulation outcomes for study systems. It was found that the performance of the model was very good in reproducing the critical period. In conclusion, it is promising given that this is the first equation to model critical period involving performance measures in Johor catchment as best of the authors’ knowledge.
Analysis of Flow Characteristics in Sewerage System
Authors: Yap Hiew Thong , Ngien Su Kong
Published: October 2015

In the present study, two parameters, the per capita flow and the design criterion, were investigated. The investigation was performed on a manhole located between the library and sports complex within Universiti Malaysia Pahang, Gambang campus (UMP Gambang) where field monitoring of sewage flows was conducted. ISCO 2150 area-velocity flowmeter was used to collect the flow data and Flowlink 5.1 software was used for data retrieval as well as display. Calibration of the flowmeter was done in the Hydraulics and Hydrology Laboratory of UMP Gambang. The study duration was from November 2014 to February 2015. Each set of data consists of sewage flow readings every 5 minutes for duration of two weeks. The same data measurement interval was applied to the rainfall data, collected through an ISCO 675 rain gauge. From the results obtained, both the parameters investigated were found to be lower than their respective values stated in the Malaysia Standard MS1228:1991. After analysis of the results, it can be concluded that the flow characteristics in the sewerage system studied is sufficient to cater to the population equivalent in the study.
The Potential and Benefits of Artificial Barrier Application at RBF
Authors: Abd Rashid Nur Aziemah , Abd Rahim Nurulezzah , Abustan Ismail , Munawar Rose Farahnadrah , Ahmad Awalludin Nur Atiqah
Published: October 2015

Water abstraction for water treatment of portable water especially riverbank filtration (RBF) is essential to be safe and clean. Due to the awareness towards the spread of contaminants and deterioration of water resources, the needs of artificial barrier is seen as crucial. An artificial barrier is a man-made vertical barrier to pre-treat the abstraction water from the water intake structure. The proposed artificial barrier is a mixture of sand (local soil), granular activated carbon (GAC) and zeolite. In this study, the three adsorbents were tested for their adsorption and permeability. The effects of adsorbent dose on the adsorption of the turbidity, iron and zinc were investigated. After treatment with sand, the levels of turbidity, iron and zinc were observed to decrease by 93.7%, 85.15% and 68.5%, respectively. For GAC, the levels of turbidity, iron and zinc decreased by 96.9%, 99.2% and 36.3%, respectively. The reduction on the levels of turbidity, iron and zinc was preferable by zeolite with 98.3%, 93.0% and 98.8%, respectively. By using Langmuir and Freundlich adsorption isotherm, the result indicated that the adsorption of adsorbents mostly obeyed Freundlich model. The relationship is an empirical equation which has an asymptotic maximum as pressure increase without bond.
Motivations and Limitations of Prefabricated Building: An Overview
Authors: El-Abidi Khaled M. Amtered , Ghazali Farid Ezanee Mohamed
Published: October 2015

Based on previous studies, prefabricated building usage motivations in the construction sector differ over time and vary from country to country. To adopt this technology, awareness on current trends and the latest innovations should be increased by reviewing previous studies. The objective of this study is to conduct a revision of common motivations and limitations of prefabricated building in the construction industry taking into consideration the experience gained and reported by several countries. Results show that the adaptation of prefabricated building mainly depends on factors such as labor shortage, labor cost, housing demand, building process efficiency, weather, as well as reduction of waste material and energy consumption. Prefabricated building has a relatively low uptake in construction industries worldwide despite its inherent economic, environmental, and social benefits.
The Study of the Implementation of Bridge Management System in Sabah
Authors: Salinah D. , Fashius M.M. , Habibah G.
Published: October 2015

Bridge Management System (BMS) is an important tool which can help to manage huge number of bridges while efficiently utilizes limited fund for maintenance. Although major bridge failure is uncommon in Sabah, the concern for future adversity must be considered. The current status of the implantation of BMS in Sabah were studied and subsequently identifying the difficulties to implement the system locally. Interviews were done in Jabatan Kerja Raya, Headquarter and districts. Five locations were selected for observation. It was discovered that the implementation status of JKR BMS is still far from a successful implementation.
Identification of Dynamic Characteristics of a Historical Church in Armenia Using Microtremor Survey Technique
Authors: Iiyama Kahori , Morikawa Hitoshi , Sasano Shiro , Motoyui Shojiro , Fujita Yasuhito , Mutoh Atsushi
Published: October 2015

Historical Churches in Armenia may have many experiences of earthquake ground motion. Thus, some of them have been damaged partially or severely. We had carried out the microtremor survey at a historical churches, which is Cathedral at Etchimiadzin around 5th century, to identify the dynamic characteristic. Four sensors are used simultaneously for the observations and modes of vibration are identified from some methods such as the Fourier spectrum and coherence function, and frequency domain decomposition (FDD) technique.
An Overview of Non – Engineered Buildings Roofing System Failure under Wind Loads
Authors: Muhammad Mohd Khairul Azuan , Majid T.A. , Ramli Noram I. , Deraman S.N.C. , Wan Chik Farah Alwani
Published: October 2015

Strong wind is an annual natural hazard in Malaysia due to the geographical location. The northeast monsoon season usually commences in early November and ends in March. During this season, steady easterly or northeasterly winds of 10 to 20 knots prevail. The strong wind events such as hurricane and storms often caused severe damage to the large number of low rise building especially at the roofing system. At end of year 2014, the series of thunderstorm hit the Northern area of Peninsular Malaysia and caused million ringgit losses. This paper is focused on the roofing system failure of the low rise houses at the rural area that constitute the great majority of the infrastructure in less affluent communities. These non-engineered structures are typically built with very little, or no technical engineering input, and are often the product of varied building traditions and cultures.
Calculation of Thermodynamic Properties in Solid-Liquid, Solid-Gas and Liquid-Gas Region
Authors: Avsec Jurij , Medveď Igor
Published: October 2015

The paper features the mathematical model of analytical calculation of thermodynamic properties like viscosity, speed of sound and thermal conductivity for fluids in one and two-phase region (fluid-solid, fluid-gas) on the basis of statistical mechanics. For the calculation of thermal conductivity and viscosity for fluids will be presented Chung-Lee-Starling model Equations for the thermal conductivity are developed based on kinetic gas theories and correlated with the experimental data. The low-pressure transport properties are extended to fluids at high densities by introducing empirically correlated density dependent functions. These correlations use acentric factor, dimensionless dipole moment and an empirically determined association parameters to characterize molecular structure effect of polyatomic molecules. The calculation of thermodynamic properties for fluids was developed under the theory of statistical thermodynamics and statistical associated fluid theory. For the calculation of thermal conductivity of solids are the most important two contributions: the heat transport by electrons (el) and by phonons (ph). In our model we have made the assumption that heat transport by electrons and by phonons is independent and the thermal conductivity is than a sum of both terms.
Uncertainty Analysis of Computational-Experimental Approach for Determination of Equivalent Thermal Conductivity of Highly Perforated Bricks
Authors: Maděra Jiří , Kočí Václav , Černý Robert
Published: October 2015

The presented paper aims at thorough uncertainty analysis of combined experimental and computational approach for determination of equivalent thermal conductivity of highly perforated bricks. The thermal conductivity is determined using experimental guarded hot plate method. However, due to large dimensions of analyzed specimens, the measurement is influenced by experimental errors due to abnormal heat leakage. Therefore, numerical modeling of heat transfer is performed in order to quantify this leakage and the resulting value of thermal conductivity is subsequently corrected. The uncertainty analysis is essential part of presented approach leading to its justification. It involves statistical errors, measurement errors as well as results of merged sensitivity analysis. Within the frame of this paper, highly perforated clay brick without cavity fillings was investigated. The results indicated that accuracy of presented approach is very sufficient and combined standard uncertainty is lower than 10 %.
In Situ Examination and Laboratory Testing of the Enclosure Wall of the Star Game Preserve
Authors: Pavlík Zbyšek , Balík Lukáš , Maděra Jiří , Pavlíková Milena , Fořt Jan , Černý Robert
Published: October 2015

The in-situ examination of the historical enclosure wall of the Star Game Preserve located in the capital of the Czech Republic, Prague, is presented in the paper, in order to obtain necessary information for a qualified design of renovation and reconstruction treatments. At the visual inspection of the researched structure, the previous reconstruction methods are identified and evaluated, together with possible moisture sources. Moreover, the damage extent and propagation are assessed. Most of the oldest as well as newly constructed parts of the enclosure wall are found in bad condition and dilapidating. On this account, the building stone (arenaceous marl) forming the original historical masonry is examined to find compatible materials for the reconstruction works. Its chemical composition is accessed by X-Ray Fluorescence analysis. For the researched stone, basic physical, mechanical, hygric and thermal properties are measured. Using the obtained data, the proper material for reconstruction purposes will be identified.
DSC Investigations of the Phase Transition in the High Strength Steel S960QL
Authors: Ślęzak Tomasz , Zmywaczyk Janusz , Koniorczyk Piotr , Sniezek Lucjan
Published: October 2015

Studies of the heat capacity temperature characteristics for microalloyed high strength steel S960QL is reported. The investigations were concentrated in the region of the second order phase transition. Experiments were carried out using the Differential Scanning Calorimeter DSC 404F1 Pegasus (Netzsch). As a tested material a sample from the high strength steel S960QL was used within temperature range of 50-1100 °C. In addition to this dilatometric investigations with the same temperature range as DSC ones were carried out using Netzsch dilatometer DIL 402C. Measurements of thermal characteristic, i.e. the heat capacity cp(T) and thermal expansion α*(T) were performed several times in order to observe thermal processes taking place in microalloyed high strength steel. Previous investigations have revealed the thermal hysteresis of the linear expansion in the region of the second order magnetic phase transition in the S960QL steel.
Material Properties of Refractory Concrete under High Temperature
Authors: Šťastník Stanislav , Šot František , Vala Jiří
Published: October 2015

The paper presents the validation of physical properties of refractory concrete with heavy filling, using the measurements under high temperature, assumed for the construction of a thermal storage. The whole system, consisting of the storage core and of the insulation container, is characterized by non-stationary thermal transfer, supplied from solar radiation into the core. The validation of behaviour of the system (including its sleeping state and the dynamics of charging and discharging) is needed for the optimization of its size parameters.
New Planar Disc Transient Method for the Measurement of Thermal Properties of Materials
Authors: Bohac Vlastimil , Dieška Peter , Vretenár Viliam , Opatt-Fidríková Danica , Štofanik Vladimír , Markovič Marian
Published: October 2015

Recently the physical model for the temperature field generated by thermophysical single-probe sensor in a shape of planar disc has been derived. The model accounts cylindrical sample having final radius and infinite length. The prototype of measuring electronics RTA was build that operates with auto balancing bridge. For the measurements the single-transition method is used. While the measurement error of the temperature response measured by thermocouple was 1% at the height of temperature response 1°C, the sensitivity of the measurement with the automatically balanced bridge is better and the signal to noise ratio is improved about 10 times. The measuring electronics was tested for measuring the temperature response using a single-sensor. This sensor generates the heat pulse and sense the temperature response in the same time. The next advantage is that the temperature response to the generated step-wise pulse is much smaller and it can be reduced to the level of 1-8° C compared to stationary method like guarded hot plate method. The effect of the temperature field generated by the probe is much smaller, which in the case of measurement of porous materials at the presence of moisture is beneficial, as the resulting redistribution of moisture under the created temperature gradient is negligible. There were derived basic models for the evaluation of this type of experiment. The probe should be in form of full cylinder or an annulus. The derived temperature function counts the outer and inner diameter of annulus. Putting the inner radius to zero we get the solution for full circle probe, so the model is universal. The model counts also the heat losses from the outer surface of the sample, when the time of measurement exceed the time when the penetration depth of generated heat pulse rich the outer radius of sample. The estimated output parameters from single measurement are the thermal conductivity, thermal diffusivity and specific heat. The heat transfer coefficient is additional parameter fitted as free parameter of the model.
Identification of Effective Material Characteristics in Semilinear Equations of Heat and Mass Transfer
Authors: Vala Jiří , Jarošová Petra
Published: October 2015

Utilization of advanced materials in civil engineering motivates research in both experimental and computational methods of reliable identification of their material characteristics, as e.g. the thermal conductivity and diffusivity in semilinear evolutionary equations of heat conduction, coming from the energy balance in classical thermodynamics, or the capillary transfer coefficient in similar equations, coming from the mass balance. The paper presents mathematical preliminaries of such inverse analysis and an overview of computational approaches with references to practical applications.
Thermo-Mechanical Analysis of Chosen Epoxy Resins Used in Aviation Technology
Authors: Prusak Kamil , Zmywaczyk Janusz , Koniorczyk Piotr , Godzimirski Jan , Cegła Marcin
Published: October 2015

In this paper the results of storage modulus (E’), loss modulus (E’’) and damping parameter tan (δ)=E''/E' of epoxy resins Epidian 57 and L285 with curing agents Z1 and LH285, respectively are presented. In addition to this the stress-strain and thermal expansion characteristics of Epidian 53, 57 and L285 were obtained experimentally in order to compare Dynamic Mechanical Analysis (DMA) results. Temperature range of DMA investigations using Netzsch (Germany) DMA 242C analyzer was from-120 °C to +110 °C at the heating rate of 1 K/min with frequency of {0.1, 1, 10} Hz, respectively. Netzsch DIL 402C dilatometer was used to study the thermal expansion of the tested samples within temperature range from 30 °C to 80 °C at 1 K/min of heating and cooling rates, respectively and Huang TA computer servo control material testing machine HT-2402 was applied to determine the stress-strain characteristics. Measurements of sample elongation ΔL and physical α* were performed twice in heating and cooling cycles. The glass transition temperature Tg determined from maximum of tan (δ) curve at f = 1Hz was equal to 76.7 °C for E57 and 87.2 °C for L285. It has been observed durable deformed shape of L285 sample with deflection in the middle about 5 mm just after finishing the DMA first run of heating which significantly affected DMA results during the second run of heating
Thermo-Mechanical Analysis of Homo- and Heterogeneous Solid Rocket Propellants
Authors: Cegła Marcin , Zmywaczyk Janusz , Koniorczyk Piotr , Borkowski Jacek , Prusak Kamil
Published: October 2015

The paper analyses results of experimental research of homogeneous and heterogeneous solid rocket propellants. The homogeneous sample PAC with density 1.58 g/cm3 and heterogeneous sample H2 with density 1.77 g/cm3 were both subjected to complex thermo-mechanical analysis. The thermo-physical properties of both samples were determined using KD2 Pro apparatus made by Decagon Devices, Inc. (USA). The temperature characteristics of thermal conductivity k (T), thermal diffusivity D(T), and volumetric heat capacity C(T) were measured within the temperature range from-200 C to +800 C. Mechanical properties such as storage modulus (E’), loss modulus (E’’) and tan (delta) were measured using Netzsch DMA 242C analyser within temperature range from-1200 C to +800 C at heating rate of 2K/min. The rectangular test samples were subjected to the dual cantilever mode with frequency f = 1Hz recommended by the NATO 4540 standard. Special attention was devoted to determining the glass transition temperature and softening temperature of the propellants. The temperature values obtained during DMA experiments supported by thermo-physical properties are essential for safe usage of solid rocket propellants under operating conditions and they may be applied in numerical modeling of temperature and thermal stress distributions of such materials.
Diatomite/Palm Wax Composite as a Phase Change Material for Latent Heat Storage
Authors: Fořt Jan , Trník Anton , Pavlíková Milena , Pavlík Zbyšek
Published: October 2015

Wider application of commercially produced phase change materials in production of building composites is limited due to their higher price and the inert polymer encapsulation which negatively affects mechanical parameters. This paper is focused on preparation of the composite material for energy savings. The phase change composite is prepared by soaking palm wax into the structure of diatomite powder using vacuum impregnation method. The compatibility of diatomite and palm wax in a newly developed PCM structure is investigated by FTIR spectroscopy. The improved thermal storage properties obtained by DSC analysis reveal melting temperature at 55.9°C and the phase change latent heat of 78.0 J/g. The laser diffraction based devise is used to determine the particle size distribution in order to assess the suitability of the developed wax/diatomite based composite for the cement based building materials. The obtained results indicate promising results from the point of view of improved latent heat storage at reasonable cost.
New Approaches to the Thermal Design of Energy Saving Buildings
Authors: Jarošová Petra , Vala Jiří
Published: October 2015

European directive on energy performance of buildings (2010) and related national technical rules force reduction of energy consumption of both new and reconstructed buildings due to the so-called passive standard. Consequently the thermal design of such buildings, utilizing advanced materials, structures and technologies, requires proper analysis of relevant physical processes, unlike classical evaluations of thermal resistance from one-dimensional stationary heat conduction. The paper demonstrates a possibility of compromise between complicated multi-physical models and realistic thermal estimation of buildings, as well as some optimization procedures in building design leading to energy reduction.
Thermal and Kinetic Characteristics of some Oil Shale Samples
Authors: Kaljuvee Tiit , Kuusik Rein , Petkova Vilma
Published: October 2015

The thermal behaviour of different oil shale samples (Estonia, Jordan, Israel, Morocco) were studied using a Setaram Setsys 1750 thermoanalyzers coupled to a Nicolet 380 FTIR Spectrometer. The experiments were carried out under non-isothermal heating conditions up to 1000 °C at different heating rates in an oxidizing atmosphere. A model-free kinetic analysis approach based on the differential isoconversional method of Friedman was used to calculate the kinetic parameters. The thermooxidative decomposition of oil shale samples proceeded in three steps. Firstly, thermooxidation of volatile organic compounds occurred – depending on the heating rate, up to 460 °C. Secondly, thermooxidation of heavier part of organic matter (kerogen) and fixed carbon as well as thermooxidation of pyrite proceeded up to 580 °C. Finally, carbonates contained in oil shale samples decomposed up to 870 °C. The combined TG-FTIR study of thermooxidative decomposition of samples made it possible to identify in addition to CO2 and H2O as major gases evolved a number of gaseous species like CO, SO2, COS, methane, ethylene, etc. formed and evolved at that. The value of activation energy E in the low-temperature oxidation region was for Estonian and Jordanian oil shale samples lower than that in the high-temperature region which was contrary for Israeli and Moroccan oil shale samples. Therefore, the results obtained indicated the complex multi-step character of the thermooxidative decomposition of the oil shale samples studied.
Effect of Carbonation on Long-Term Measurements of Sorption Isotherms of Autoclaved Aerated Concrete
Authors: Koronthalyova Olga , Bagel Ľubomír
Published: October 2015

The laboratory measurement of water vapour adsorption/desorption curves is a standard tool for determination of the moisture capacity of porous building materials in hygroscopic region. However, in case of cementitious materials, additional processes like carbonation can occur during the measurement. Generally, process of carbonation affects the pore structure of the material and results in an increase of its bulk density. Therefore, for determination of correct sorption curves the carbonation caused bulk density increase has to be eliminated. In this work the both mentioned effects of carbonation on the measured water vapour sorption isotherm were quantified for autoclaved aerated concrete (AAC). Within the monitored 9-year period, the carbonation caused noticeable changes in microstructure of the tested AAC samples, namely a decrease of the specific surface area of pores and the portion of very small pores. These microstructure changes affected the moisture storage capacity too – the obtained equilibrium moisture contents of the partly carbonated AAC were lower than the ones of the AAC close to the original state. It was also confirmed that in case of continuous measurement of the water vapour sorption curve the carbonation induced bulk density increase could result in an overestimation of the equilibrium moisture contents.