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作者： Castanheira, Deborah Souza De Lima, Luciano Rodrigues Ornelas Da Silva Vellasco, Pedro Colmar Gončalves Da Nóbrega Tavares, Maria Elizabeth PGECIV Civil Engineering Post Graduate Program UERJ State University of Rio de Janeiro Rio de Janeiro Brazil Structural Engineering Department UERJ State University of Rio de Janeiro Rio de Janeiro Brazil

Structural elements made of seam-welded hollow sections are considerably less expensive than their seamless equivalents. This is a strong incentive for their use, but the current steel design standards still contain recommendations for seam-welded hollow sections based on test results performed with sections produced using outdated steel grades and fabrication processes. These design procedures are even more conservative when applied to composite tubular seam-welded elements. This paper presents an experimental campaign performed to investigate the structural behaviour of steel- and concrete-filled composite columns made with seam-welded rectangular hollow profiles. The experiments involved columns with only steel sections, concrete-filled and concrete-filled plus additional reinforcing bars. The main aim of the tests was to identify the contribution of each component in the overall structural response. The results enable an evaluation of the design recommendations present in Eurocode 4 aiming to determine less conservative buckling curves to be used for the investigated composite columns made of seam-welded rectangular hollow sections.

关键词： Reinforced concrete

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Evaluation of phase formation and physical-mechanical properties of Portland cements produced with civil construction waste

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CEMENT 2021年 5卷

作者： F.N. Costa D.V. Ribeiro Post-Graduate Program in Civil Engineering (PPEC)/Federal University of Bahia Rua Aristides Novis 02. Federação Salvador BA 40210-630 Brazil Department of Materials Science and Technology Federal University of Bahia Rua Aristides Novis 02. Federação Salvador BA 40210-630 Brazil

Cement is the most widely used building material worldwide. Its production demands a large amount of natural resources, in addition to high energy consumption. Thus, the cement industry has been looking for solutions that effectively reduce the use of these resources as well as greenhouse gas emissions. This research aims to show the technical feasibility of incorporating civil construction waste (CCW) in the production of Portland cement. To this purpose, the physicochemical characterization of the raw materials used was carried out, dosage and manufacture of the raw mix, which were calcined at 1450 °C. Clinkers were characterized mineralogically, by means of XRD, to verify the formation of the crystalline phases. Subsequently, the clinkers were ground, resulting in Portland cements, and their physical-mechanical properties were evaluated. The results showed the potential of using CCW as an alternative raw material, since experimental cements presented performance similar to industrial cements used as a reference.

关键词： civil construction waste (CCW Reuse Environment Cement Compressive strength

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Effects of TiO 2 waste on the formation of clinker phases and mechanical performance and hydration of Portand cement

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CEMENT 2022年 9卷

作者： José S. Andrade Neto Bruna B. Mariani Nilson S. Amorim Júnior Daniel V. Ribeiro Laboratory of Testing on Materials Durability (LEDMa) / Federal University of Bahia Rua Aristides Novis 02. Federação. 40210-630. Salvador/BA Brazil Post-Graduate Program in Civil Engineering (PPEC) / Federal University of Bahia Aristides Novis 02. Federação. 40210-630. Salvador/BA Brazil Department of Materials Science and Technology / Federal University of Bahia Aristides Novis 02. Federação. 40210-630. Salvador/BA Brazil

The incorporation of different levels of UOW into Portland clinker raw meals and its effects on the clinker and cement properties were evaluated. Clinkers were produced and characterized by X-ray diffractometry (XRD) and optical microscopy; the cements were produced and physically characterized. Finally, pastes were produced and analyzed using isothermal calorimetry, thermogravimetry, XRD, and compressive strength tests. UOW, when added up to 1.29% in Portland clinker raw meal, acts as a mineralizer, increasing the content of alite by 6.44%. The incorporation of UOW reduces the hydration rate in the first days owing to the increase in the size of the alite crystals and delays the point of sulfate depletion due to the increase in the SO 3 content of the clinkers. Owing to the higher content of alite formed, the cement produced from the raw meal with 1.29% of UOW presents the highest early mechanical strength (up to 7 days).

关键词： Portland clinker Unreacted ore waste (UOW) Mineralizer Hydration

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Optimization of parameters in biomethanization process with co-digested poultry wastes and palm oil mill effluents

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Cleaner Chemical engineering 2022年 3卷

作者： Emmanuel Ikechukwu Ugwu Juliana Heloisa Pinê Américo-Pinheiro Light Ihenna Nwobia Vineet Kumar Eberechukwu Laura Ikechukwu Egba Chinonso Victor Department of Civil Engineering Michael Okpara University of Agriculture Umudike P.M.B 7267 Umuahia Abia State Nigeria Post-graduate Program in Environmental Sciences Brazil University Street Carolina Fonseca 584 São Paulo SP 08230-030 Brazil Department of Botany School of Life Sciences Guru Ghasidas Vishwavidyalaya (A Central University) Bilaspur Chhattisgarh 495009 India Department of Biochemistry Michael Okpara University of Agriculture Umudike P.M.B 7267 Umuahia Abia State Nigeria

Poultry wastes (PW) and palm oil mill effluents (POME) are thought to be promising starting materials for biogas production. In the present study, the optimization of biomethanization process from co-digested (PW) and POME was investigated. To assist digestion, samples were sun-dried, ground, and mixed with water to form slurry. The central composite design was used in the experimental design, while the desirability function was applied in the process optimization of the co-digestion process. The interactive effects of temperature, pH, and hydraulic retention time were equally studied. The results showed a high co-efficient of determination (R 2 ) value of 0.9920. Also, the predicted and experimental values obtained were 4377.71 ml and 4379.01 respectively, while the optimum conditions obtained were 45 °C, 8.00 and 15 days for temperature, pH, and hydraulic retention time, respectively. This finding shows that the proposed technique is effective and robust in predicting biomethane generation from co-digested POME and PW.

关键词： Biogas yield Bio-methanization Central composite design Co-digestion Co-efficient of determination Interactive effects Process optimization

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Road infrastructure asset management strategy and its impact on the environment

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IOP Conference Series: Materials Science and engineering 2020年第2期830卷

作者： K Priyatiningsih M Sutrisno Lecturer of Asset Management Study Program Politeknik Negeri Bandung Bandung 40012 Indonesia Student of Management Science Doctoral Program School of Post Graduate Universitas Pendidikan Indonesia Bandung Indonesia Lecturer of Civil Engineering Politeknik Negeri Bandung Bandung 40012 Indoenesia

The development of the economic sector is determined by services to the public through reforms that aim to place public satisfaction through the management of road infrastructure assets. Some research on road infrastructure assets still requires a deepening of studies related to the delivery of public services related to asset management systems. The purpose of this study is to find an appropriate road infrastructure asset management strategy through an integrated asset management system and asset management policies that can provide public satisfaction. This comprehensive approach to management strategies ensures that the performance of service provider assets is in line with the expectations of stakeholders including road users. This descriptive qualitative research is based on the perspective of road users as respondents, consisting of vehicle drivers from 50 transportation companies (people or goods) through interviews and observations. The results show aspects of asset performance based on the user's perspective there are five aspects, namely productivity, efficiency, effectiveness, use of resources and institutions and this performance is integrated in the asset management system related to policies from the management authority through service delivery namely quality and mobility, risk and use and maintenance of resources. The conclusion of this research is that road infrastructure asset services can be improved through the concept of road infrastructure asset management strategies in an integrated management system with five aspects of performance and more directed towards asset management policies related to the provision of road infrastructure asset services.

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Visual assessment deterioration analysis of runways at Sultan Aji Muhammad Sulaiman Sepinggan Airport Balikpapan

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AIP Conference Proceedings 2019年第1期2114卷

作者： Yanti Sri Sunarjono Agus Riyanto Nurul Hidayati Alfia Magfirona 1Civil Engineering Post Graduate Program Universitas Muhammadiyah Surakarta Surakarta Central Java Indonesia

Sultan Aji Muhammad Sulaiman Sepinggan (SAMS) Airport has an important role as the gateway of economic activity in Balikpapan, East Kalimantan. Elements of the airport consist of runways, taxiway, apron and the terminal building of departure and arrival. The runway has an important role as a key element in airport infrastructure, this is related to aircraft and passenger safety in air traffic at SAMS Airport, which is currently one of the best airports in Indonesia that meets the International Standard qualification. The purpose of this study is to perform visual assessment of runway deterioration at SAMS Airport using PCI (Pavement Condition Index) method, to know the factors affecting runway deterioration and the effective distress treatment to overcome deterioration at a runway. The visual assessment data are collected from PT. Angkasa Pura I (Persero) Sepinggan, by measuring the types and area of deterioration occurring on the runway during 1-month period (in September 2018), then PCI is analyzed by using ASTM D 5340 – 98. The results show that the PCI value is 80.4 which means the rating is excellent. The most common typical distress occurred at Threshold Runway 25 section 1 with the type of distress is block cracking which mainly caused by asphalt concrete shrinkage and daily temperature condition resulting in stress or strain series, another type is depression initially caused by the settlement from the soil foundation or construction process. Since PCI shows excellent state, the distress repair treatment to be performed is surface repair or routine maintenance with partial mill and overlay method.

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Study of soil structure interaction on basement wall with variants in distance and depth of the basement on soil class SE

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Journal of Physics: Conference Series 2020年第5期1529卷

作者： Yetty Saragi Masyhur Irsyam Roesyanto Hendriyawan University of HKBP Nommensen Sutomo Street No.4A Medan 20234 Indonesia Post Graduate Program Civil Engineering Departement University of Sumatera Utara Medan North Sumatera 20155 Indonesia Institute of Technology Bandung Ganesha 10 Bandung West Java 40135 Indonesia Civil Engineering Departement University of Sumatera Utara Medan North Sumatera 20155 Indonesia

The function of the basement is to carry the weight of the upper structure into the soil and to resist lateral loads around the basement wall. One aspect of geotechnical engineering that often a problem in basement wall planning is the determination of lateral ground pressure in the basement wall due to earthquake which must be held by the basement wall. In this study, an analysis of the effects of local soil conditions due to dynamic loads is done through analysis of soil-structure interaction. The analysis is done by modeling the local soil with variations in basement depth and the adjacent basement distance to get the lateral pressure distribution due to dynamic load. The analyzed soil conditions are considered homogeneous at land sites SE (soft soil) with the dynamic load input from earthquake loads uses a 10% probability of exceedance in 50 years (500 years). The most influential parameter for soil displacement is the distance of the basement and then the depth of the basement. The most influential parameter on lateral forces is the depth of the basement followed by the distance of the basement.

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Analytical model of retrofitted reinforced concrete beam column joints after experiencing severe damage from earthquake load simulation using SAP2000

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IOP Conference Series: Materials Science and engineering 2019年第1期508卷

作者： N Gosal I Imran M Riyansyah Post Graduate Program of Faculty of Civil Engineering Bandung Institute of Technology 40132 Bandung Indonesia Structural Engineering Department Faculty of Civil Engineering Bandung Institute of Technology 40132 Bandung Indonesia

An earthquake resistant structure should be able to perform as expected when it's struck by an earthquake such as it may experience slight damage and should be able to be repaired to its original state when struck by a design level earthquake. However, there are still debates whether reparation should also be viable when structures are experiencing severe damage. There are still a little to no studies about repairing severely damaged structures, therefore a study was made to see how severely damaged structures behaved after being repaired. Two beam column joints are used as specimens, which were severely damaged by an earthquake simulation before getting repaired. Both their initial and repaired condition are then modeled analytically using SAP2000. Their behaviors such as plastic hinges, joint's shear deformation, bond slip, and rebars' residual strain and stress due to previous loading are also implemented to the model. Although the lateral strength of the specimens are similar to their analytical model, the other behavior, especially their stiffness is not similar, therefore needing another parameter implemented in the model.

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Comparative study of asphalt concrete characteristic between ideal gradation and laboratory tested gradation with crumb rubber

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IOP Conference Series: Materials Science and engineering 2019年第1期650卷

作者： Asep Sundara Risna Rismiana Sari Tanya Audia Balqis Civil Engineering Department Politeknik Negeri Bandung Bandung Indonesia Post-Graduate Student of Infrastructure Engineering Study Program Applied Master Program Politeknik Negeri Bandung Bandung Indonesia

Modifying asphalt concrete with using Crumb Rubber (CR) can provide environmental benefits. The method used in this study is an experimental laboratory with Mashall machine. The tests used two types of gradation, namely the gradations of Ideal and Laboratory Test. CR used in a mixture with a dry process method to replacement 0%, 5%, 15% and 20% of the weight aggregate at fraction No. 30 (0.6 mm). The results showed that the Ideal gradation mixture has a better characteristic than the mixture of laboratory tested gradations. Ideal gradations can increased stability into 10% from Laboratory Test gradations for mixture without CR. Addition of CR contect in AC mixture did not significantly effect for the characteristics. To ensure the effect of CR in mixture, further test must be taken.

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The Effect of EPS Addition to Soil Stabilized with Fly Ash as Lightweight Fill Materials for Embankment Construction

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Journal of Physics: Conference Series 2019年第1期1364卷

作者： Syahril Andri Krisnandi Somantri Aditia Febriansya Civil Engineering Department Politeknik Negeri Bandung Bandung Indonesia Civil Engineering Department Politeknik Negeri Bandun Bandung Indonesia Post-Graduate Student of Infrastructure Engineering Study Program Applied Master Program Politeknik Negeri Bandung Bandung Indonesia

Design and construction of road embankment presents several challenges, including the possibility of bearing capacity failure, large total settlement, differential settlement, and slope instability, which may result from the weight of the embankment construction itself, and/or weak foundation. A number of techniques have been developed and can be used to overcome these problems, one of them is by modifying the weight of the embankment itself with the use of lightweight materials, such as soil-EPS mixture. The use of soil-EPS mixture as lightweight material provides several advantages, among which can achieve the same volume or elevation requirement with a significantly lighter weight compared to ordinary materials, improving slope stability, embankment over high compressibility soil, and to reduce soil pressure to soil retaining structures, abutment or bridge pillar. Fly ash also added to act as binder to increase shear strength of mixture. The result of the compaction test shows that the addition of a small amount of EPS to the mixture can significantly reduce the maximum dry density of the mixture. Triaxial UU and UCS test results show a reduction in mixture strength as EPS contents increase, but due to the presence of fly ash increases the strength of mixture as the number of day increases, so that the use of lightweight materials has the potential to be one of soil improvement solutions.

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