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Wettability and Surface Free Energy of Mineral-Asphalt Mixtures with Dolomite and Recycled Aggregate

IOP Conference Series: Materials Science and engineering 2019年第3期471卷

作者： Wojciech Andrzejuk Danuta Barnat-Hunek Stanisław Fic Joanna Styczeń Pope John Paul II State School of Higher Education in BiałaPodlaska Faculty of Economics and Engineering Sidorska Str. 95/97 21-500 BiałaPodlaska Poland Lublin University of Technology Faculty of Civil Engineering and Architecture Department of Construction Nadbystrzycka Str. 40 20-618 Lublin Poland

The study on the wetting properties and surface free energy (SFE) of mineral-asphalt mixtures was presented in the paper. The composition of the two mineral-asphalt mixtures was prepared: the mixtures with dolomite and the mixtures with dolomite and recycled ceramic aggregate. The use of different aggregates results in diversification of the wetting properties in porous bituminous mixtures. The microstructure was shown based on the SEM study. The wetting properties of mineral-asphalt mixtures were determined by measuring the contact angle of their surface using water as measuring liquid. Measurements were carried out immediately after the time of application of the drops. The total surface free energy (SFE) was determined using the Neumann method. While analysing the examination results it can be noticed that the values of contact angles depends on the type of aggregate used in mixtures and the smoothness of mineral-asphalt mixtures surface. The highest contact angle was noticed for the bituminous mixture with dolomite aggregate on flat surface. The smallest contact angle with water was obtained for the mineral-asphalt mixture with dolomite and recycled ceramic aggregate on rough surface. This is due to the physical characteristics of this aggregate. Ceramic aggregate is characterized by the high absorbability. This indicates an increased wettability and adhesion properties.

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Research on seismic performance of large underground structures of urban rail transit 19

Research on seismic performance of large underground structu...

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19th International Conference on Soil Mechanics and Geotechnical engineering, ICSMGE 2017

作者： Ding, Deyun Yang, Xiuren Zhao, Ji Liu, Baoshun Beijing Jiuzhouyigui Shock and Vibration Isolation Technology Co. Ltd. China Beijing Urban Construction Design and Development Group Co. Limited China School of Civil Engineering Beijing Jiaotong University China

With a speedy development of urban rail transit in China, a lot of large underground structures have been built. After the Wenchuan earthquake in 2008, there are more and more concerns on the earthquake-resistance of large underground structures. Taken a large underground structure as engineering background, the seismic characteristics of a large underground structure under design and high-level earthquake actions are researched. Three-dimensional dynamic models are established by using the finite element program MIDAS/GTS. Through the time-history analysis method, the deformation and internal forces response of a large underground structure are obtained. Seismic performance analysis of large underground structures of urban rail transit should be considered under design and high-level earthquake actions in their design phase. Research results can be regarded as a valuable reference for the seismic design of large underground structures. © 2017 19th ICSMGE Secretariat. All rights reserved.

关键词： Geotechnical engineering

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Preliminary Study on Multilayer Bulletproof Concrete Panel: Impact Energy Absorption and Failure Pattern of Fibre Reinforced Concrete, Para-Rubber and Styrofoam Sheets

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Procedia engineering 2017年 210卷 369-376页

作者： Buchit Maho Sittisak Jamnam Piti Sukontasukkul Kazunori Fujikake Nemkumar Banthia Construction and Building Materials Research Center Department of Civil Engineering King Mongkut’s University of Technology North Bangkok Bangkok 10800 Thailand Department of Civil and Environmental Engineering National Defense Academy of Japan Yokosuka Japan Department of Civil Engineering University of British Columbia Vancouver Canada

This manuscript presents the preliminary test results from the multilayer bulletproof concrete panel project. The purposed multilayer panel consisted of steel fibre reinforced concrete, Para-rubber and Styrofoam sheet. In this study, the failure patterns and energy absorption of each material with different thickness subjected to direct fire arm with 9 and 11 mm. bullets were investigated. The obtained information will later be used in designing the multilayer bulletproof concrete panel based on combination of energy absorption. The results showed that the energy absorption of each material increased with the increasing thickness. In case of FRC, the energy absorption also depended on fibre type and volume fractions. Comparing at the same thickness, FRC was the most effective energy absorption followed by Para-rubber and Styrofoam sheet.

关键词： Bulletproof concrete panel Impact energy absorption fibre reinforced concrete Styrofoam sheet Para-rubber sheet

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Effect of binder content and water-binder ratio in mortar developed using partial replacement of cement with palm oil clinker powder

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IOP Conference Series: Materials Science and engineering 2018年第8期431卷

作者： Mathialagan Sumesh U Johnson Alengaram Ramappa Ramesh Nayaka Centre for Innovative Construction Technology (CICT) Department of Civil Engineering Faculty of Engineering University of Malaya 50603 Kuala Lumpur Malaysia

The manufacture of cement leads to almost 5 to 7% of the total production of carbon dioxide which causes greenhouse effect. So, it is vital to replace the ordinary Portland cement by the other binders which have the similar or better properties than cement. Besides, the recent interests on the palm oil industrial wastes in the development of mortar led to research works on usefulness of these wastes in construction materials. The palm oil industry produces many wastes such as oil palm shell, palm oil fuel ash (POFA) and palm oil clinker powder (POCP). In this research work, an experimental study was conducted to investigate the effects of different binder contents, and water-binder (w/b) ratio on the development of mortars. Conventional ordinary Portland cement was replaced with 40% of POCP and the total binder contents of 450, 500 and 550 kg/m3 with w/b ratios of 0.45, 0.35 and 0.32 used. The properties of mortars were evaluated for fresh and hardened properties; XRD characteristic was also studied. Test results showed that the strength of mortar specimens improved as the binder content increased with subsequent decrease in w/b ratio. POCP mortar specimens with binder content of 550kg/m3 with cement replacement of 40% produced 28-day compressive strength of 45.3 MPa, compared to 65.12 MPa for control cement mortar (CM). The value of flow diameter of 40% replacement of POCP mortar was 108.51 mm and this was 16.6% lower compared to control mortar. Though POCP based mortar produced a strength reduction of about 36.6%, its usefulness in achieving acceptable strength and sustainable aspect of reducing 40% of conventional cement could be considered significant.

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Influence of palm oil clinker powder on the fresh and mechanical properties of masonry mortars

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IOP Conference Series: Materials Science and engineering 2018年第8期431卷

作者： Ramappa Ramesh Nayaka U Johnson Alengaram Mohd Zamin Jumaat Sumiani Binti Yusoff Mathialagan Sumesh Centre for Innovative Construction Technology (CICT) Department of Civil Engineering Faculty of Engineering University of Malaya 50603 Kuala Lumpur Malaysia

Masonry and rendering mortars are is well known oldest techniques in the building. A common idea is to use strong material as possible, and as a result mortars are often rich in cement. Not only this is unnecessary expensive, it has also technical disadvantages and harmful to environment. Hence, in this study focuses on utilisation of palm oil mills waste, namely palm oil clinker powder (POCP) and POCP influences on the fresh and mechanical properties of masonry mortars are analysed and comparison between cement – lime (CLM) and masonry cement mortar (MCM) are addressed. The masonry mortars were prepared using cement – lime and masonry cement as control masonry mortars christened as type 'S' mortar. The POCP used as cement replacement material in the masonry mortar mixture from 0-80% by volume in the preliminary study and ideal replacement of 40% was used in the final mixture of mortar for comparison. All specimens were cured in water and air curing regimes for 7, 28 and 56 days and the physical and mechanical properties were analysed. The results show that as replacement of cement with POCP increases, there is a reduction in fresh density with subsequent increase in air content. Further, the use of masonry cement with POCP (MCP) shows highly workable mix even at lower w/cm ratio compared to cement-lime mortar with POCP (CLP). Moreover, CLM, CLP obtained higher strength (28 & 20 MPa) than MCM and MCP (24 MPa & 11 MPa). on the contrary, the cement-lime mortar with POCP shows higher compressive strength compared to masonry mortar prepared with masonry cement-POCP.

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Analysis of rainfall trends in Syria 2nd

Analysis of rainfall trends in Syria

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2nd International Conference on engineering Sciences and Technologies, ESaT 2016

作者： Zeleňáková, M. Alkhalaf, I. Purcz, P. Blišťan, P. Portela, M.M. Institute of Environmental Engineering Technical University of Kosice Kosice Slovakia Institute of Construction Technology and Management Technical University of Kosice Kosice Slovakia Institute of Geodesy Cartography and Geographical Information Systems Technical University of Kosice Kosice Slovakia Department of Civil Engineering National Technical University of Lisbon Lisbon Portugal

ISBN: (纸本)9781315393827

The Intergovernmental Panel on Climate Change (IPCC) provides a comprehensive review of the potential impacts on the hydrological variables of the man induced climate changes. It states that such changes will likely increase runoff in the higher latitude regions because of increased precipitation;also, the flood frequency is expected to change in some locations and the severity of drought events could also increase as a result of the changes both in precipitation and evaporation. Observations show that changes are occurring in the amount, intensity, frequency and type of precipitation. The frequency of extreme temperatures during the summer is likely to be higher. The Mann-Kendall test coupled with the Sen’s slope was applied to identify the significant trends, positive or negative trend and the magnitude of those trends. The results achieved for rainfall revealed more frequent significant decreasing trends in Syria in the last 19 years. © 2017 Taylor & Francis Group, London, UK.

关键词： Rain

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Pressure distribution of TAM grouting under a deep excavation in silty soil 19

Pressure distribution of TAM grouting under a deep excavatio...

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19th International Conference on Soil Mechanics and Geotechnical engineering, ICSMGE 2017

作者： Liao, Hung-Jiun Cheng, Shih-Hao Lu, Sin-Lan Chiu, Chin-Lung Wong, Ricky K.N. Department of Civil and Construction Engineering National Taiwan University of Science and Technology Taipei Taiwan Taiwan Building Technology Center National Taiwan University of Science and Technology Taipei Taiwan Department of Technology CECI Nova Technology Co. Ltd Taipei Taiwan Taipei Branch SanShin Corporation Ltd. Taipei Taiwan

This paper will report a Tube-a-Manchette (TAM) grouting project carried out in the silty sand and gravel layer to seal off the bottom of a deep excavation against uplift of high groundwater pressure. The excavation was up to 33 m in depth and was retained by diaphragm wall 53 m deep. The base grouting zone covered the interface zone between sandy and gravel *** grouting method was adopted to do the grout injection. Cement-bentonite (CB) grout was injected in the first stage followed by sodium silicate grout (SL grout) in the second stage. Volume control grouting method was adopted here and the grouting pressure applied at each injection port was recorded. Based on the recorded pressure and the spatial coordinates of each injection port, a mapping of grouting pressure in the grouted zone was presented in 2D image using commercial software. The 2D grouting pressure contours at a given depth can be established based on the physical data recorded during base grouting. Meanwhile, it was also found that the deviation of drill holes alignment had no obvious effect on the 2D grouting pressure distribution, if a proper TAM grouting sequence and a lateral confinement of enclosed diaphragm wall can be provided. © 2017 19th ICSMGE Secretariat. All rights reserved.

关键词： Grouting

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Using a Shallow Mixing Layer to Reinforce Deep Mixing Columns during Embankment construction 5

Using a Shallow Mixing Layer to Reinforce Deep Mixing Column...

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5th International Conference on Grouting, Deep Mixing, and Diaphragm Walls, Grouting 2017

作者： Nguyen, Binh Takeyama, Tomohide Kitazume, Masaki Institute of Technology Penta-Ocean Construction Co. Ltd. 1534-1 Yonkucho Nasushiobara-shi Tochigi329-2746 Japan Dept. of Civil Engineering Kobe Univ. 1-1 Rokkoudai Nada-ku Kobe657-8501 Japan Dept. of Civil Engineering Tokyo Institute of Technology 2-12-1 Ookayama Meguro-ku Tokyo152-8552 Japan

ISBN: (数字)9780784480809

ISBN: (纸本)9780784480809

When the deep mixing columns were used to support embankment slope, the columns may fail under either the internal or the external failure pattern, dependent on the strength of columns, soil condition, and loading condition. A shallow layer, produced by shallow mixing method, was proposed to fix and reinforce these isolated columns. In this study, the centrifuge model tests were carried out to simulate the embankment construction on the soft ground, improved by the columns and the shallow layer. The effect of the shallow layer and column strength on increasing the embankment stability can be addressed from the model tests. The failure of isolated columns was compared to that of columns with the reinforcement of shallow layer in terms of internal stability. In addition, by using the test data simple calculations based on limit equilibrium were also carried out to access the failure patterns of column in both internal and external stabilities. © ASCE.

关键词： Mixing

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Determination of Apparent Activation Energy of Calcium Sulfoaluminate Cement by Different Measurements

Determination of Apparent Activation Energy of Calcium Sulfo...

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第九届水泥混凝土国际会议

作者： Yu GUI Tishun LIAO Xiaosheng WEI Jiayin TAO Fulong KE Qing SHEN School of Urban Construction Wuhan University of Science and Technology School of Civil Engineering and Mechanics Huazhong University of Science and Technology

Apparent activation energy is usually used to quantitative characterize the temperature sensitivity of cementitious *** paper aim to compare the apparent activation energy calculated by different measurements from chemical shrinkage,electrical resistivity and heat of *** were conducted on the calcium sulfoaluminate cement paste with different amounts of fly ash and silica fume with w/b of 0.5 curing at temperatures of 20℃,30℃,40℃ and 50℃,*** on the exponential model(three parameter model).***-U method and Exponential-E method have been applied to obtain the rate of *** show that both methods are applicable to the heat of hydration measurement and the apparent activation energy of the control sample are 33.88 kJ/mol and 25.76 kJ/*** Exponential-E method is applicable to electrical resistivity measurement and Exponential-U method can be used for chemical shrinkage measurement in the calculation of apparent activation energy,the value of which is 26.02 kJ mol and 27.20 kJ/mol,***,with the increasing content of supplementary cementitious materials,the apparent activation energy of the hydration of cement pastes is decreases first and then increases.

关键词： calcium sulfoaluminale cement apparent activation energy heat of hydration electrical resistivity chemical shrinkage

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Parametric identification of multy-storey building model based on oscillation testing results

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IOP Conference Series: Materials Science and engineering 2019年第1期660卷

作者： V Volkova L Gaile L Pakrastins Department of construction geotechnics and geomechanics Dnipro University of Technology Televizionnaya 12. ap.48 Dnipro UA49005 Ukraine Faculty of Civil Engineering Riga Technical Riga University 1 Kalku Street Riga LV-1658 Latvia

Buildings and structures are complex systems having predetermined parameters, which should be controlled in the process of manufacturing structures, construction and installation. In some cases, oscillations are the most dangerous effects on the buildings and structures. Significant alternate stresses caused by oscillational actions leads to accumulation of damage in the material. It causes the appearance of fatigue cracks and destruction. In addition to fatigue failure in mechanical systems there are other phenomena that cause changes in the structure of the surface layers of the parts to be joined and consequently the reduction of the frictional force in the joint. The object of the study is a multi-storey building having a rectangular shape in plane. Structural scheme of the building is a two spans frame. The frame of the building consists of monolithic reinforced concrete structures. According to the analysis of the basic diagnostic parameters of the technical condition of buildings and structures, affect their stability and reliability are geometrical parameters of buildings and structures, and their main structural elements, as well as physical and mechanical parameters of structural elements of building and dynamic parameters of buildings and structures. An analysis of methods for determining the dynamic parameters of buildings has shown that the main criteria for assessing the technical condition of bearing structures, using the dynamic method, is the period and frequency building oscillation. Dynamic tests were conducted to determine the dynamic and rigid characteristics of bearing structural elements of the building and structures, detection of hidden defects. According to the method of measuring the dynamic parameters, the degree of damage to a building or structure, is determined by the comparison of the design values of dynamic parameters, periods of eigenoscillations, and the decrement of oscillations with experimentally obtained data.

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