U.Porto Journal of Engineering最新文献_第4页

Experimental Investigation of Snail Shell-based Cement Mortar: Mechanical Strength, Durability and Microstructure 蜗牛壳基水泥砂浆的力学强度、耐久性和微观结构试验研究

U.Porto Journal of Engineering Pub Date : 2023-09-22 DOI: 10.24840/2183-6493_009-004_001131

Alla Suseela, SS. Asadi

{"title":"Experimental Investigation of Snail Shell-based Cement Mortar: Mechanical Strength, Durability and Microstructure","authors":"Alla Suseela, SS. Asadi","doi":"10.24840/2183-6493_009-004_001131","DOIUrl":"https://doi.org/10.24840/2183-6493_009-004_001131","url":null,"abstract":"Snail shells are the discarded bio-shell waste from restaurants, and oceans creating huge environmental problems for society. Living organisms are harmed when these shells are released. As previously stated, the work focuses primarily on the utilisation of snail shell powder as a raw ingredient in cement mortar. The mechanical and durability features of snail shell-based cement mortar were compared to the nominal mortar in this study. Snail shell powder, ranging from 0% to 35%, was used to partially substitute cement in mortar, with a variation of 5%. XRD (X-Ray Diffraction) was used to determine the chemical composition of both mixes. The mechanical properties of mortar for both mixes were determined using a compressive strength test. The tests on cement mortar viz., Water Absorption, Sorptivity, Acid Durability, and Rapid Chloride Permeability Test (RCP Test) were compared with nominal mortar mix. According to the results of the investigation, the optimum use of snail shell powder is 30%. The durability of both mixes increased by the increase of the snail shell powder. To detect the C-S-H gel formations, microstructural analysis was performed for both mixes.","PeriodicalId":36339,"journal":{"name":"U.Porto Journal of Engineering","volume":"78 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136060329","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

Dynamic effects on the lattice boom crane due to the wind, moving load and earthquake events 风、动荷载和地震事件对格架臂起重机的动力影响

U.Porto Journal of Engineering Pub Date : 2023-09-22 DOI: 10.24840/2183-6493_009-004_001945

Luigi Solazzi, Nicola Danzi

引用次数: 0

Design of an innovative self-compacting material modified with recycled steel fibers and spent equilibrium catalyst for ultra-high performance applications 设计一种创新的自密实材料，用回收的钢纤维和废平衡催化剂改性，用于超高性能应用

U.Porto Journal of Engineering Pub Date : 2023-09-22 DOI: 10.24840/2183-6493_009-004_001741

Hassan Abdolpour, Paweł Niewiadomski, Łukasz Sadowski, Arkadiusz Kwiecień

{"title":"Design of an innovative self-compacting material modified with recycled steel fibers and spent equilibrium catalyst for ultra-high performance applications","authors":"Hassan Abdolpour, Paweł Niewiadomski, Łukasz Sadowski, Arkadiusz Kwiecień","doi":"10.24840/2183-6493_009-004_001741","DOIUrl":"https://doi.org/10.24840/2183-6493_009-004_001741","url":null,"abstract":"The main aim of the present study is to design an innovative self-compacting material modified with recycled steel fibers (RSF) from waste tires and spent equilibrium catalyst (Ecat) from the petrochemical industry for ultra-high performance application. For this purpose, 17 different mixtures were developed and analysed using different percentages of RSF (0%-3%) and replacement of cement by different percentages of Ecat (0%-15%). The developed mortars' self-compatibility was evaluated in a fresh stage using mini-cone tests. Regarding the hardened stage, the mortars were characterized at the ages of 7 days and 28 days using compression and unnotched flexural tests. The abilities of RSF to increase the post-cracking behavior of the specimens and to use Ecat to increase the bond performance between RSF and the cement matrix were assessed by performing notched three-point bending tests. The results of notched flexural tests were used to obtain the residual flexural strength in service limit state (SLS), ultimate limit state (ULS), and two equivalent flexural strengths. The experimental results for the fresh stage demonstrated that inclusion of RSF and Ecat significantly reduced the workability of mortars. The beneficial use of RSF and Ecat was observed to increase compressive strength and flexural strength for 7 days and 28 days of tested specimens. Notched flexural tested specimens showed that the addition of RSF and Ecat can significantly decrease the brittle behavior of cement-based materials by improving its toughness and post-cracking resistance. Middle-span deflection, crack initiation load, and ultimate flexural load were also increased with the addition of RSF and Ecat. In this sense, the results of this research showed that RSF and Ecat seem to have the potential to constitute a sustainable material for structural and nonstructural applications.","PeriodicalId":36339,"journal":{"name":"U.Porto Journal of Engineering","volume":"72 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136061313","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

Understanding Spatial Cognition for Designing Pedestrian Wayfinding Systems 了解空间认知对行人寻路系统设计的影响

U.Porto Journal of Engineering Pub Date : 2023-08-21 DOI: 10.24840/2183-6493_009-002_002081

Lara Costa Bomfim, S. Santos Cruz

{"title":"Understanding Spatial Cognition for Designing Pedestrian Wayfinding Systems","authors":"Lara Costa Bomfim, S. Santos Cruz","doi":"10.24840/2183-6493_009-002_002081","DOIUrl":"https://doi.org/10.24840/2183-6493_009-002_002081","url":null,"abstract":"Individuals react differently when moving in urban spaces, as their senses are distinctively activated. Their interpretations and how the built environment is perceived result in different meanings. When studying public spaces, it is of utmost importance to understand how residents and visitors construct images of the city, by perceiving and appropriating urban spaces. In particular, this is decisive when designing Pedestrian Wayfinding Systems (PWS) in urban areas. \u0000Based on spatial cognition studies, this paper identifies and explores the main aspects influencing the design of wayfinding systems. The study is structured in three main parts. First, the article reviews literature on spatial cognition and human behaviors. Second, it analyzes some reference cases considered good practices for PWS, their implementation in contemporary public spaces, and their visual and aesthetic forms of expression. Third, it develops a practical guide for designing a PWS focused on end-users. More specifically, the research aims to support the municipality of Porto in defining the tender specifications for the development of a PWS, to be included in the future Integrated Signage and Information System. \u0000Ultimately, this study proposes recommendations to improve pedestrian navigation in the urban context and help decision-makers, designers, and urban planners potentially create better wayfinding systems in the future.","PeriodicalId":36339,"journal":{"name":"U.Porto Journal of Engineering","volume":"38 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80696316","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

The Challenges in Understanding Urban Identity 理解城市身份的挑战

U.Porto Journal of Engineering Pub Date : 2023-08-10 DOI: 10.24840/2183-6493_009-002_002207

Hasan Mansour, F. B. Alves, A. Costa

引用次数: 0

Recycling Potential of Onyx Composite for Additive Manufacturing 玛瑙复合材料增材制造的回收潜力

U.Porto Journal of Engineering Pub Date : 2023-04-28 DOI: 10.24840/2183-6493_009-003_001845

Marina Mergulhão, Sofia Magalhães, J. M. Costa

引用次数: 0

Waste Elimination based on Lean Construction and Building Information Modelling: A Systematic Literature Review 基于精益建筑和建筑信息模型的废物消除:系统文献综述

U.Porto Journal of Engineering Pub Date : 2023-04-28 DOI: 10.24840/2183-6493_009-003_001808

Mahmoud Karaz, J. C. Teixeira

引用次数: 0

Bicycle mobility 自行车出行

U.Porto Journal of Engineering Pub Date : 2023-04-28 DOI: 10.24840/2183-6493_009-003_001962

Cauê Rios, Cecília Silva

引用次数: 0

Power System Voltage Collapse Mitigation Employing Optimization Based Dynamic Voltage Stability Analysis 基于优化动态电压稳定分析的电力系统电压崩溃缓解

U.Porto Journal of Engineering Pub Date : 2023-04-28 DOI: 10.24840/2183-6493_009-003_001645

B. V, Chandra Shekhar Reddy Atla, M.R.Shivakumar

{"title":"Power System Voltage Collapse Mitigation Employing Optimization Based Dynamic Voltage Stability Analysis","authors":"B. V, Chandra Shekhar Reddy Atla, M.R.Shivakumar","doi":"10.24840/2183-6493_009-003_001645","DOIUrl":"https://doi.org/10.24840/2183-6493_009-003_001645","url":null,"abstract":"Maintaining voltage stability is an important factor in modern power system study and operation. Supplementing the system with reactive power (VAr) support devices such as FACTS helps to overcome voltage instability issues. Commonly, dynamic optimization based method is employed to study the dynamic Voltage Stability Analysis (VSA) of the system. The existing dynamic optimization approach has dependencies on the availability of specific tools and the FACTS model to perform dynamic VSA. Besides, the application of the existing method for the voltage collapse phenomenon is not addressed in detail. It is desirable to have a generic dynamic VSA approach that does not have dependencies on specific tools and the FACTS model. This paper proposes a new generic approach to carry-out dynamic VSA with any given DAE tool. A method of emulating the FACTS device’s behaviour for dynamic VAr injection is introduced using an incremental optimization approach. A generic interface is newly developed as a Modifiable Off The Shelf (MOTS) component to couple the DAE solver and optimization solver. The existing approach is enhanced into a generic dynamic optimization framework by integrating incremental optimization technique and the generic interface. Voltage collapse phenomenon on IEEE-9 bus system is investigated employing the enhanced framework. Post contingency behaviour of the system illustrates the successful mitigation of voltage collapse issues. Obtained results show the effectiveness of the new generic approach in performing dynamic VSA.","PeriodicalId":36339,"journal":{"name":"U.Porto Journal of Engineering","volume":"61 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90367554","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

Surface pathology on the walls of limestone and mortar masonry 石灰石和灰浆砌筑墙的表面病理

U.Porto Journal of Engineering Pub Date : 2023-04-28 DOI: 10.24840/2183-6493_009-003_001493

José Maria Carvalho Belo Ximenes, Carlos de Jesus, J. Aguiar

引用次数: 0