Journal of Civil Engineering and Construction最新文献_第3页

Assessing the Degree of Polish on Hardened Concrete Air Void Parameters 硬化混凝土气孔参数抛光程度的评定

Journal of Civil Engineering and Construction Pub Date : 2022-11-15 DOI: 10.32732/jcec.2022.11.4.177

R. Villarreal, A. Torres, Federico Aguayo, Carlos Moro

{"title":"Assessing the Degree of Polish on Hardened Concrete Air Void Parameters","authors":"R. Villarreal, A. Torres, Federico Aguayo, Carlos Moro","doi":"10.32732/jcec.2022.11.4.177","DOIUrl":"https://doi.org/10.32732/jcec.2022.11.4.177","url":null,"abstract":"This study provides much needed insight regarding how the degree of polish on a concrete sample affects the hardened air void parameters. As required by ASTM C457, each hardened concrete sample assessed by any of its three procedures needs to be polished until light reflects off of the surface. However, there is currently little to no insight as to how various degrees of polish will affect the concrete air void parameters. This research aims to fill the gap in the literature by providing a step-by-step procedure, materials necessary, and most importantly, the effect of the degree of polish on the hardened air void system parameters. Four target air void percentages (control at 2%, low at 3 – 5%, medium at 5 – 7%, and high at >8%) were investigated. Two different polishing mediums (silicon carbide and diamond) were investigated at six different polishing pad grit sizes. The results show that the most economical and preferred polishing method uses diamond polish pads. The results also indicate that the first polishing step is crucial in producing a suitable surface for further analysis, which requires using the coarsest polishing medium. Therefore, the results indicate that any further polishing (at finer degrees of polish) is negligible in obtaining the hardened air void parameters following ASTM C457 procedures. The average percent difference across each polish pad grit size investigates was 3.8%. This value amounted to an average hardened air void difference of only 0.1 across all samples. Comparing the average hardened air void percentage across all polish pad grit sizes to the ASTM C231 fresh air percentage reveals an average difference of 6.7%, which constituded a difference of 0.3. Therefore, the results show non-statistically significant variations between any of the degrees of polish investigated, especially between the coarsest polishing medium and the finest polishing medium, which produces the reflective surface as stipulated in ASTM C457.","PeriodicalId":243788,"journal":{"name":"Journal of Civil Engineering and Construction","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133180864","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

The Relation of the Method Used in Tunneling Operations with the Geological Structure Example of the Black Sea Coastal Road 黑海海岸公路地质构造实例与隧道施工方法的关系

Journal of Civil Engineering and Construction Pub Date : 2022-11-15 DOI: 10.32732/jcec.2022.11.4.255

Gökhan Külekçi

{"title":"The Relation of the Method Used in Tunneling Operations with the Geological Structure Example of the Black Sea Coastal Road","authors":"Gökhan Külekçi","doi":"10.32732/jcec.2022.11.4.255","DOIUrl":"https://doi.org/10.32732/jcec.2022.11.4.255","url":null,"abstract":"Transportation tunnels are the most preferred method to facilitate transportation in mountainous and rough terrains. The excavation method and the choice of fortification tools in tunnel construction depend on the geological structure of the tunnel route. Correct formation determination and determination will reduce the cost and eliminate many risks. The Black Sea region has a very mountainous and rugged terrain. The most obvious method used to overcome rough terrain is road tunnels. The rock classification of the tunnel route and the support to be formed accordingly are very important in the selection of the method to be applied in the highway tunnel constructions. Within the scope of this study, Trabzon-Akyazi region, which is an important part of the Black Sea coastal road, was studied. The geological formations on the route of the 3-lane and double-tube tunnel with a length of approximately 2476 meters, which is planned to be built within the highway passing through this region, were examined and the method used in the tunnel construction was determined. As a result of the analyzes and calculations, it has been determined that the dominant unit along the tunnel routes is the agglomerate of the Besirli formation and the New Austrian Tunneling (NATM) method is applicable. The rock classes found were determined to be B3 and C2 classes according to NATM. Excavations in the tunnel were carried out by drilling and blasting method in the form of the upper half and the lower half.","PeriodicalId":243788,"journal":{"name":"Journal of Civil Engineering and Construction","volume":"253 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132387237","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

Increased Bending Strength in Beam Samples Using Waste Textile Fibers 利用废纺织纤维提高梁样的弯曲强度

Journal of Civil Engineering and Construction Pub Date : 2022-11-15 DOI: 10.32732/jcec.2022.11.4.228

Aylin Özodabaş

引用次数: 0

The Effect of Mineral Pigments on Mechanical Properties of Concrete 矿物颜料对混凝土力学性能的影响

Journal of Civil Engineering and Construction Pub Date : 2022-08-15 DOI: 10.32732/jcec.2022.11.3.139

Amr El Nemr, M. A. Shawky, M. E. El Khafif

{"title":"The Effect of Mineral Pigments on Mechanical Properties of Concrete","authors":"Amr El Nemr, M. A. Shawky, M. E. El Khafif","doi":"10.32732/jcec.2022.11.3.139","DOIUrl":"https://doi.org/10.32732/jcec.2022.11.3.139","url":null,"abstract":" Pigmented concrete exhibits artesian properties in addition to ordinary concrete properties, explicitly high strength, excellent durability, and weather resistance. However, the influence of several parameters that affect the characteristics of colored concrete should be studied; extensively. In this paper, the impact of the w/b (water/binder) ratio using color pigments on the mechanical properties such as compressive and flexural strengths of colored cement mortar prisms and cubes experimentally investigated. The experimental program included 21 mixes with six cubes and three flexural prisms specimens for assessing compressive and flexural strength, respectively. The blends included different water/binder ratios with values of 0.4, 0.5, and 0.6, in addition to several color pigments as a partial replacement of cement. The percentage of replacements altered between 0, 2.5%, 5% and 7.5% with two different shades of pigments consisting of red iron and green chromium oxide. Based on the experimental results, empirical expressions were generated based on Abram’s law to assess the relationship between the compressive strength of colored concrete and w/b ratio. The results revealed that the compressive and flexural strength of colored concrete is influenced by w/b ratio and partially replacement percentage of cement by color pigment not proportionally direct. Furthermore, the shade of pigments also has a different impact as well.","PeriodicalId":243788,"journal":{"name":"Journal of Civil Engineering and Construction","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131997493","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

Challenges in Modelling Reinforced Concrete Panels Subjected to Blast Load - A Critical Review 爆炸荷载下钢筋混凝土板建模的挑战——综述

Journal of Civil Engineering and Construction Pub Date : 2022-08-15 DOI: 10.32732/jcec.2022.11.3.127

A. Mohammed, H. Almansour

引用次数: 0

A New Proposal for Live Load Distribution Factors of Bridges with Transverse Beams 横向梁式桥梁活载分配系数的新建议

Journal of Civil Engineering and Construction Pub Date : 2022-08-15 DOI: 10.32732/jcec.2022.11.3.166

Mohammad Bagher Abrishamkar, Reza Kholghi, S. Maleki

{"title":"A New Proposal for Live Load Distribution Factors of Bridges with Transverse Beams","authors":"Mohammad Bagher Abrishamkar, Reza Kholghi, S. Maleki","doi":"10.32732/jcec.2022.11.3.166","DOIUrl":"https://doi.org/10.32732/jcec.2022.11.3.166","url":null,"abstract":"Many bridge superstructures use transverse beams as load carrying components. In these systems, usually the transverse beams are connected to the main longitudinal girders or trusses on the two sides of the bridge. Such systems are commonly used in plate girder, box girder, cable-stayed and truss bridges. The live load distribution factor (LLDF) for bridge superstructures with transverse beams in AASHTO-LRFD bridge design specification has remained unchanged for decades and is prescribed as a function of the distance between the transverse beams. However, for slab-beam superstructures in which longitudinal beams at close spacing carry the loads to the substructure, the LLDFs have gone through many changes throughout the years and in their current forms depend on many parameters such as concrete slab thickness, beam span, longitudinal beam stiffness as well as the distance between the longitudinal beams. This study investigates the factors affecting the LLDF for transverse beams and intends to obtain new equations similar to AASHTO’s longitudinal beam equations. For this purpose, 3D finite element models of different sample bridges were developed and critical parameters affecting the LLDF were identified and varied. Accordingly, the LLDFs for moment and shear forces of transverse beams were obtained through regression analyses. The proposed equations have less than 3.1% of average error for the cases considered.","PeriodicalId":243788,"journal":{"name":"Journal of Civil Engineering and Construction","volume":"126 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121871115","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

Design and Validation of an Accurate Low-Cost Data Acquisition System for Structural Health Monitoring of a Pedestrian Bridge 一种用于人行天桥结构健康监测的低成本数据采集系统设计与验证

Journal of Civil Engineering and Construction Pub Date : 2022-08-15 DOI: 10.32732/jcec.2022.11.3.113

Reina El Dahr, X. Lignos, Spyridon Papavieros, I. Vayas

{"title":"Design and Validation of an Accurate Low-Cost Data Acquisition System for Structural Health Monitoring of a Pedestrian Bridge","authors":"Reina El Dahr, X. Lignos, Spyridon Papavieros, I. Vayas","doi":"10.32732/jcec.2022.11.3.113","DOIUrl":"https://doi.org/10.32732/jcec.2022.11.3.113","url":null,"abstract":"Structural health monitoring (SHM) is an effective operating technique devoted to enhance the robustness of an infrastructure, and to validate its safety requirements. The aim of SHM is to determine a structure’s reaction when subjected to any type of excitation, by means of identifying modifications in basic vibration measurements and modal parameters such as natural frequencies, damping and mode shapes. Consequently, sensors are mounted on a structure intending to record data on equal time intervals basis prior to, during and after an induced stimulation. Therefore, the necessity to adopt a computer-based data acquisition (DAQ) technique is required in this analytical approach in order to evaluate vibrational signals collected by sensors placed on a structure. In this work an accurate microcontroller-based DAQ system is proposed to monitor a pedestrian bridge located in Athens Greece for the purpose of characterizing the system state and evaluate the modal properties of the investigated structure. Four low-cost yet accurate triaxial accelerometers were systematically placed along the bridge intending to report the system response toward different generated perturbations. The proposed monitoring and computational system was tested in laboratory conditions prior to the bridge assessment. Three triaxial accelerometer were installed on a steel cantilever beam. A comparative analysis between the results of the suggested DAQ system and that of the standard laboratory DAQ system National Instrument DAQ was performed to test the accuracy of the suggested framework.","PeriodicalId":243788,"journal":{"name":"Journal of Civil Engineering and Construction","volume":"52 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115958264","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

State-of-the-Practice Review on the Field-Curing Methods for Evaluating Strength of Concrete Test Specimen 现场养护法评定混凝土试件强度的实践进展

Journal of Civil Engineering and Construction Pub Date : 2022-08-15 DOI: 10.32732/jcec.2022.11.3.153

Pranshoo Solanki, Hai-dong Xie

{"title":"State-of-the-Practice Review on the Field-Curing Methods for Evaluating Strength of Concrete Test Specimen","authors":"Pranshoo Solanki, Hai-dong Xie","doi":"10.32732/jcec.2022.11.3.153","DOIUrl":"https://doi.org/10.32732/jcec.2022.11.3.153","url":null,"abstract":"The purpose of this research was to build up the understanding of the current state –of –the practice for field-curing methods of concrete specimens. Specifically, a comprehensive literature review and questionnaire survey were prepared to identify the selection criteria and details of field-curing methods correspondingly. The comparison of literature data and survey outcomes shows that most transportation agencies use field-cured cylinders followed by the maturity method for the decision on when to open pavement to traffic or remove form/falsework. The most commonly used field method was curing near (or on) the casted concrete in the same manner as concrete item represented. The cylindrical specimens are mostly field cured in insulated boxes such as a cooler or under burlap/insulation near the concrete item. On the other hand, beams are mostly field-cured in a damp sandpit or under burlap/insulation near the concrete item. The information provided in this paper could be used by transportation agencies for determining an appropriate cost-effective field-curing technique which is representative of strength gain of the in-place concrete item. ","PeriodicalId":243788,"journal":{"name":"Journal of Civil Engineering and Construction","volume":"79 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125965220","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

Development of Poor Productivity Mitigation Model for a Viaduct Bridge Project 高架桥项目低生产率缓解模型的开发

Journal of Civil Engineering and Construction Pub Date : 2022-05-15 DOI: 10.32732/jcec.2022.11.2.75

Dionisios Serras

{"title":"Development of Poor Productivity Mitigation Model for a Viaduct Bridge Project","authors":"Dionisios Serras","doi":"10.32732/jcec.2022.11.2.75","DOIUrl":"https://doi.org/10.32732/jcec.2022.11.2.75","url":null,"abstract":"Poor productivity is a common phenomenon in the construction industry. Poor or lack of project knowledge management continues to plague the construction process especially in relation to project delays. At the same time, the human resource function has undergone dramatic change, owing, it would seem, to greater use of rapidly evolving information technology. The goal of this paper is to investigate how the choice of the human resource management strategy would positively impact both the organizational and project performance. The research methodology adopted for this study comprised three steps. First, the productivity problems encountered during the construction operations of a viaduct bridge are reviewed and reported using interviews on the potential factors contributing directly and indirectly to more effective project operations. Second, the least squares method is utilized to prioritize and rank the importance, impact, and effect of these factors. Third, a scalable and transferable poor productivity mitigation model is developed. The adopted model incorporates concepts from knowledge management, project learning and supervisory controls. Results of this research indicate that knowledge management and generally the human resource management strategy is a key factor for project success.","PeriodicalId":243788,"journal":{"name":"Journal of Civil Engineering and Construction","volume":"2013 11","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114125852","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

Clean Hydrocarbon Refrigerant Explosion Hazards 清洁碳氢制冷剂爆炸危险

Journal of Civil Engineering and Construction Pub Date : 2022-05-15 DOI: 10.32732/jcec.2022.11.2.104

W. Chow, Tsz-Kit Yue, Y. Ng, Zheming Gao, Ye Gao

{"title":"Clean Hydrocarbon Refrigerant Explosion Hazards","authors":"W. Chow, Tsz-Kit Yue, Y. Ng, Zheming Gao, Ye Gao","doi":"10.32732/jcec.2022.11.2.104","DOIUrl":"https://doi.org/10.32732/jcec.2022.11.2.104","url":null,"abstract":"Explosion hazards are fire safety concerns resulting from the development of clean hydrocarbon refrigerants (environmental friendly flammable refrigerants) to reduce the emission of substances with high global warning potential. Several clean hydrocarbon refrigerants are flammable with propane. Explosion hazards due to flammable refrigerant leakage from refrigerators put inside a small cupboard may give a concentration higher than its lowest flammability. A small amount of ignition energy can ignite the flammable gas to give combustion. Limiting the pressure development in a small cupboard will result in deflagration, and then transition to detonation. Since the compositions of many of environmental friendly flammable refrigerants are not disclosed and odourless, it is very difficult to assess their hazard upon leakage. This study reveals that the hidden hazard of environmental friendly flammable refrigerants would lead to serious consequences using earlier experimental studies on explosion. This is a big problem taking time to solve. Indoor aerodynamics would affect the mixing between leaked refrigerant with air in the room. Appropriate ventilation should be provided to avoid keeping the heavier explosive gas at lower levels. Different ventilation modes with air inlets and outlets at high and low positions should be considered. Use of environmental friendly flammable refrigerants and the ways in protecting against possible explosion hazards for refrigerators commonly put in kitchen cupboards in small rooms, inter alia, economy-class hotel rooms, small apartments, or subdivided units in densely populated cities, such as Hong Kong have to be watched. At the moment, fire safety management must be enhanced to address the problem.","PeriodicalId":243788,"journal":{"name":"Journal of Civil Engineering and Construction","volume":"63 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127323144","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