Acta Polytechnica最新文献_第9页

Cyclic response of RC beam-column joints strengthened with transverse steel bars and with C-FRP diagonal ties 横向钢筋加固和C-FRP斜拉筋加固RC梁柱节点的循环响应

IF 0.8

Acta Polytechnica Pub Date : 2022-05-05 DOI: 10.14311/ap.2022.62.0274

Emmanouil Golias, E. Vougioukas, K. Wittemann, G. Kalogeropoulos, C. Karayannis

{"title":"Cyclic response of RC beam-column joints strengthened with transverse steel bars and with C-FRP diagonal ties","authors":"Emmanouil Golias, E. Vougioukas, K. Wittemann, G. Kalogeropoulos, C. Karayannis","doi":"10.14311/ap.2022.62.0274","DOIUrl":"https://doi.org/10.14311/ap.2022.62.0274","url":null,"abstract":"The use of additional bars, internally placed through drill holes, in external beam-column connections subjected to cyclic loading, as shear reinforcement is experimentally investigated.The presented experimental work includes tests of full-scale specimens with different reinforcement arrangements in the joint area, they are as follows: (a) the JB0V control specimen with two (extra) vertical side bars without shear reinforcement in the joint area and, (b) the JB0R joint, same as in the case of the control specimen, without the extra vertical bars, but with four additional steel bars that were placed in holes, which were drilled through the concrete of the joint body for this purpose, (c) the JB0VFX joint, the damaged control specimen repaired and strengthened with C-FRP diagonal ties (rope connections) through the joint area. The effectiveness of these additional bars and ropes as a shear reinforcement on the overall seismic performance of the tested joint is examined.A comparison between the test results of the examined specimens indicated that the applied retrofitting technique is appropriate for the enhancement of the overall hysteretic performance of the beam-column joints in terms of load carrying capacity, stiffness and hysteretic energy dissipation.","PeriodicalId":45804,"journal":{"name":"Acta Polytechnica","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2022-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44336012","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

CFD modelling of a secondary settling tanks: generalization based on database relations 二沉池CFD建模：基于数据库关系的推广

IF 0.8

Acta Polytechnica Pub Date : 2022-05-05 DOI: 10.14311/ap.2022.62.0313

O. Švanda, J. Pollert

引用次数: 1

Load carrying capacity of masonry arch railway bridges at the serviceability limit state 使用极限状态下铁路砌体拱桥的承载能力

IF 0.8

Acta Polytechnica Pub Date : 2022-05-05 DOI: 10.14311/ap.2022.62.0322

M. Vokál, M. Drahorád

引用次数: 0

ZnO-Zeolite nanocomposite application for photocatalytic degradation of procion red and its adsorption isotherm ZnO-沸石纳米复合材料在光催化降解procion红中的应用及其吸附等温线

IF 0.8

Acta Polytechnica Pub Date : 2022-05-05 DOI: 10.14311/ap.2022.62.0238

T. Agustina, Rianyza Gayatri, D. Bahrin, R. Moeksin, Gustini

{"title":"ZnO-Zeolite nanocomposite application for photocatalytic degradation of procion red and its adsorption isotherm","authors":"T. Agustina, Rianyza Gayatri, D. Bahrin, R. Moeksin, Gustini","doi":"10.14311/ap.2022.62.0238","DOIUrl":"https://doi.org/10.14311/ap.2022.62.0238","url":null,"abstract":"In this paper, the photocatalytic degradation of procion red dye, one of the most frequently used dyes in the textile industry, was studied. The objective of the research is to study the ZnO-Zeolite nanocomposite application to degrade procion red dye by using different irradiation sources. The adsorption isotherm was also investigated. The ZnO-Zeolite nanocomposite was prepared by a sol-gel process. Photodegradation test was applied under the sunlight irradiation, ultraviolet (UV) lamp, and in a darkroom. The dye degradation was also examined by the synthetic zeolite and ZnO for a comparison. Another objective of this study is to analyse the appropriate adsorption isotherm to describe the degradation process of procion red dye by using ZnO-Zeolite nanocomposite. The adsorption ability of the nanocomposite was described by Langmuir and Freundlich isotherms. The adsorption of the nanocomposite was reported to depend on the degradation time. The highest photodegradation result of 98.24 % was achieved by irradiating 50 mg/l of procion red dye under the sunlight for 120 minutes. The result showed that the Langmuir adsorption isotherm was the appropriate adsorption equation for the degradation process of procion red dye by using ZnO-Zeolite nanocomposite with R2 value of 0.995. ","PeriodicalId":45804,"journal":{"name":"Acta Polytechnica","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2022-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47942074","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effect of pigments on bond strength between coloured concrete and steel reinforcement 颜料对彩色混凝土与钢筋粘结强度的影响

IF 0.8

Acta Polytechnica Pub Date : 2022-05-05 DOI: 10.14311/ap.2022.62.0248

J. Assaad, Matthew Mata, Jad Saade

{"title":"Effect of pigments on bond strength between coloured concrete and steel reinforcement","authors":"J. Assaad, Matthew Mata, Jad Saade","doi":"10.14311/ap.2022.62.0248","DOIUrl":"https://doi.org/10.14311/ap.2022.62.0248","url":null,"abstract":"The effect of pigments on mechanical properties of coloured concrete intended for structural applications, including the bond stress-slip behaviour to embedded steel bars, is not well understood. Series of concrete mixtures containing different types and oncentrations of iron oxide (red and grey colour), carbon black, and titanium dioxide (TiO2) pigments are investigated in this study. Regardless of the colour, mixtures incorporating increased pigment additions exhibited higher compressive and splitting tensile strengths. This was attributed to the micro-filler effect that enhances the packing density of the cementitious matrix and leads to a denser microstructure. Also, the bond to steel bars increased with the pigment additions, revealing their beneficial role for improving the development of bond stresses in reinforced concrete members. The highest increase in bond strength was recorded for mixtures containing TiO2, which was ascribed to formation of nucleus sites that promote hydration reactions and strengthen the interfacial concrete-steel transition zone. The experimental data were compared to design bond strengths proposed by ACI 318-19, European Code EC2, and CEB-FIP Model Code.","PeriodicalId":45804,"journal":{"name":"Acta Polytechnica","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2022-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45799391","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Bearing capacity of damaged reinforced concrete beams strengthened with metal casing 金属套管加固受损钢筋混凝土梁的承载力

IF 0.8

Acta Polytechnica Pub Date : 2021-12-31 DOI: 10.14311/ap.2021.61.0703

I. Karpiuk, D. Danilenko, V. Karpiuk, Anna Danilenko, T. Lyashenko

{"title":"Bearing capacity of damaged reinforced concrete beams strengthened with metal casing","authors":"I. Karpiuk, D. Danilenko, V. Karpiuk, Anna Danilenko, T. Lyashenko","doi":"10.14311/ap.2021.61.0703","DOIUrl":"https://doi.org/10.14311/ap.2021.61.0703","url":null,"abstract":"Experimental data on the bearing capacity of damaged reinforced concrete beams with the dimensions of 2000×200×100 mm, reinforced with prestressed metal casings, are presented. Damaging in the form of through normal and crossing inclined cracks, as well as excessive vertical moving of the beam were obtained during previous tests for the effect of high-level transverse alternating loads.The authors of the article have developed a method and equipment for restoring and strengthening damaged reinforced concrete beams using a casing. Beams are manufactured and tested in accordance with the three-level design of an experiment.Previously damaged and reduced to the ultimate (pre-emergency) state, the beams were strengthened with the declared method and equipment, and then retested. New data on the bearing capacity of ordinary and damaged beams, as well as reinforced concrete elements strengthened with casings and tested for the action of transverse forces and bending moments were obtained. The research results are presented in the form of experimental-statistical dependences of the bearing capacity of the support areas, deformability and crack resistance of the investigated elements on the ratio of the most significant design factors and external factors. A comparative analysis of the influence of these factors on the main parameters of the bearing capacity of ordinary as well as previously damaged and then strengthened test beams is carried out.The possibility and appropriateness of using the proposed method of strengthening reinforced concrete beams damaged by through normal and cross-inclined force cracks in the conditions of an existing production has been experimentally proved.","PeriodicalId":45804,"journal":{"name":"Acta Polytechnica","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2021-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45821811","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Assessment of external interface of autonomous vehicles 自动驾驶汽车外部接口评估

IF 0.8

Acta Polytechnica Pub Date : 2021-12-31 DOI: 10.14311/ap.2021.61.0733

Adam Orlický, A. Mashko, J. Mík

引用次数: 0

Hydrothermally-calcined waste paper ash nanomaterial as an alternative to cement for clay soil modification for building purposes 水热煅烧废纸灰纳米材料作为建筑用粘土改性水泥的替代品

IF 0.8

Acta Polytechnica Pub Date : 2021-12-31 DOI: 10.14311/ap.2021.61.0749

U. Robert, S. Etuk, O. Agbasi, G. Umoren, Samuel Sunday Akpan, L. Nnanna

{"title":"Hydrothermally-calcined waste paper ash nanomaterial as an alternative to cement for clay soil modification for building purposes","authors":"U. Robert, S. Etuk, O. Agbasi, G. Umoren, Samuel Sunday Akpan, L. Nnanna","doi":"10.14311/ap.2021.61.0749","DOIUrl":"https://doi.org/10.14311/ap.2021.61.0749","url":null,"abstract":"It has been observed that clay soil cannot be used for building design, unless it is modified by firing or with cement. Either method of stabilization can adversely affect the environment and public health just like indiscriminate dumping or open burning adopted in developing countries as the prevalent disposal technique for waste papers. This paper sought to examine the feasibility of using assorted waste papers to derive an alternative stabilizer to Portland Limestone Cement for modification of clay soil into composite materials suitable for building design. Specifically, clay-based composites were fabricated at 0 %, 5 %, 10 %, 15 %, and 20% replacement levels by weight with cement, and then hydrothermally-calcined waste paper ash nanomaterial (HCWPAN). Water absorption, sorptivity, bulk density, thermal conductivity, specific heat capacity, thermal diffusivity, flaking concentration, flexural strength, and compressive strength were investigated for each of the fabricated samples. Irrespective of the stabilizing agent utilized, 10% loading level was found to be the optimum for possession of maximum mechanical strength by the samples. Only samples with the HCWPAN content were found to be capable of reducing building dead loads and improving thermal insulation efficiency over un-stabilized clay material, if applied as walling elements in buildings. Generally, it was revealed that the cement and HCWPAN have comparable influences on the properties of clay soil, thus indicating that HCWPAN could be utilized as an alternative stabilizer to cement. In addition, the preparation of HCWPAN was found to be more energy-saving than that of the cement.","PeriodicalId":45804,"journal":{"name":"Acta Polytechnica","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2021-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43480078","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Geotechnical and microstructural properties of cement-treated laterites stabilized with rice husk ash and bamboo leaf ash 稻壳灰和竹叶灰稳定水泥处理红土的岩土力学和微观结构特性

IF 0.8

Acta Polytechnica Pub Date : 2021-12-31 DOI: 10.14311/ap.2021.61.0722

E. S. Nnochiri, O. Ogundipe, S. Ola

{"title":"Geotechnical and microstructural properties of cement-treated laterites stabilized with rice husk ash and bamboo leaf ash","authors":"E. S. Nnochiri, O. Ogundipe, S. Ola","doi":"10.14311/ap.2021.61.0722","DOIUrl":"https://doi.org/10.14311/ap.2021.61.0722","url":null,"abstract":"This study investigated the geotechnical and microstructural properties of cement-treated laterites stabilized with rice husk ash and bamboo leaf ash. In going about the tests, the soil sample was subjected to compaction, California Bearing Ratio (CBR) and preliminary tests; such as specific gravity, particle size distribution and Atterbergs limits to determine its index properties. Thereafter, the soil sample was mixed with cement at varying proportions of 0–12% at 2% intervals and also, separately mixed with bamboo leaf ash (BLA) and rice husk ash (RHA) in proportions of 0–16% at 2% intervals. The mixes at each stage were subjected to compaction, Atterberg limits and CBR tests. The highest values were 66.7% and 54.8% for unsoaked and soaked CBR at 6% cement+8% BLA and 78.5% and 63.8% for unsoaked and soaked CBR at 8% cement+8% RHA. Samples at these optimal CBR values were subjected into Scanning Electron Microscopy (SEM) and X-Ray Diffraction (XRD) tests. Results showed that new compounds were formed and there were changes in the microstructural arrangements. It can therefore be concluded that pozzolanic and cement hydration reactions actually took place in the course of stabilization.","PeriodicalId":45804,"journal":{"name":"Acta Polytechnica","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2021-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43108637","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Comparision of the walk techniques for fitness state space analysis in vehicle routing problem 车辆路径问题适合度状态空间分析中步行技术的比较

IF 0.8

Acta Polytechnica Pub Date : 2021-12-31 DOI: 10.14311/ap.2021.61.0672

A. Agárdi, L. Kovács, T. Bányai

引用次数: 0