Civil and environmental research最新文献_第5页

Experimental Study on Mechanical Behaviour of Glass Fiber Reinforced Polymer Bars under Compression 玻璃纤维增强聚合物棒材受压力学性能试验研究

Civil and environmental research Pub Date : 2021-08-01 DOI: 10.7176/cer/13-5-05

Weldeselassie Danayt Abraham, Wodajo Sara Desalegn, X. Fang, Yan Hongmei, Liang Min

{"title":"Experimental Study on Mechanical Behaviour of Glass Fiber Reinforced Polymer Bars under Compression","authors":"Weldeselassie Danayt Abraham, Wodajo Sara Desalegn, X. Fang, Yan Hongmei, Liang Min","doi":"10.7176/cer/13-5-05","DOIUrl":"https://doi.org/10.7176/cer/13-5-05","url":null,"abstract":"The requirements for using GFRP bars are growing as several researchers have shown the functionality of bars in concrete columns. The demand to characterize the mechanical properties of GFRP bars is therefore rising, although there is no standardized test method for evaluating the compressive behavior of these bars. This experimental study presents the determination of the mechanical properties of GFRP composite bars in compression, namely the stress-strain curves, compressive strength, ultimate crushing strain, and modulus of elasticity. The compressive properties of these bars were calculated following ASTM D695-10 (Compression Test) with some modifications. A total of 27 specimens were tested for the proposed test procedure. The diameter of the GFRP tendon used in the test was 10, 12, and 14 mm, and the length to bar diameter ratio L e /d b (4, 8, and 16) was investigated for the compressive strength of the bars. These two parameters were used to establish the relationship between the length to diameter ratio and strength. Besides, two steel caps with a length of 50 mm each were installed to both ends of each specimen to avoid premature failure. It was observed that the test method enables to successfully evaluate the compressive characteristics of the GFRP bars. Experimental discussions were performed based on the test results from stress-strain curves, bar graphs, and scatter curves. The results indicate the increase in length to diameter ratio decrease the buckling stress and the compressive to tensile strength ratio for L e /d b ratio of 16 specimens in buckling failure mode. The failure mode transformed from crushing to buckling and a combination of crushing and buckling between the two different failures modes with an improvement in the L e /d b ratio. It shows that there was no yield section on the test specimens during the entire test loading process. The compressive GFRP bars present typical brittle failure.","PeriodicalId":10219,"journal":{"name":"Civil and environmental research","volume":"3 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88561139","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

A Review of Some Indices Used for Drought Monitoring 干旱监测的一些指标综述

Civil and environmental research Pub Date : 2021-08-01 DOI: 10.7176/cer/13-5-01

Abel Balew, Behailu Legese, Madda Walabu

{"title":"A Review of Some Indices Used for Drought Monitoring","authors":"Abel Balew, Behailu Legese, Madda Walabu","doi":"10.7176/cer/13-5-01","DOIUrl":"https://doi.org/10.7176/cer/13-5-01","url":null,"abstract":"Drought is a natural hazard that results from a deficiency of precipitation and water availability from expected or normal amounts, usually extended over a season or longer period. Drought can be hydrological, meteorological, agricultural and socio-economical. It affects the ecology, biodiversity, hydrology and climate and economy and the wellbeing of the societies at local, regional and global levels. Drought causes for significant environmental and economic problems, which in turn affect the balance of food supply and demand leads to poverty. Therefore, drought monitoring and prediction and warning system is a very essential component to minimize vulnerabilities and risks. In this regard, drought indices play a great role. The objective of this review is to show different available drought indices used for monitoring drought events. For investigating drought using a single index is not providing better results, therefore, integrating different indices is recommended because the environmental variable is spatially different and the indices do not use the same model and there are gaps in the model. Thus, by integrating different indices it is possible to achieve better drought results.","PeriodicalId":10219,"journal":{"name":"Civil and environmental research","volume":"43 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88044317","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

Evaluating The Perception of Climate Change Among Secondary School Science Teachers for Knowledge-Based Sustainable Development 基于知识可持续发展的中学科学教师气候变化认知评估

Civil and environmental research Pub Date : 2021-08-01 DOI: 10.7176/cer/13-5-03

Valentine E. Nnadi, Nkechi G. Nnoli, Ikenna C. Ezeasor, Obiageli J. Okolo, Violet U. Nnadi, Ketanduoma N. Okorocha

{"title":"Evaluating The Perception of Climate Change Among Secondary School Science Teachers for Knowledge-Based Sustainable Development","authors":"Valentine E. Nnadi, Nkechi G. Nnoli, Ikenna C. Ezeasor, Obiageli J. Okolo, Violet U. Nnadi, Ketanduoma N. Okorocha","doi":"10.7176/cer/13-5-03","DOIUrl":"https://doi.org/10.7176/cer/13-5-03","url":null,"abstract":"There appears to be lack of knowledge about the cause and effect of climate change amongst the secondary school students. This asks for evaluation of their source of knowledge in schools through the assessment of their teachers’ knowledge and/or perception about climatic change. The survey research design was adopted and the perception of the secondary school science teachers’ (SSSTs) evaluated using questionnaire. The results showed that SSSTs perception of human activities associated with climate change and the effects of human activities associated with climate is moderate. This was very clear when the grand mean responses of the teachers were found to be 2.81 and 2.61 respectively. The student t-test statistics used at P>0.05 confirmed that there is no significant difference between the perception of urban and rural SSSTs on their perception of climate change. At P>0.05, there is significant difference between experienced and less experienced SSSTs on their perception of climate change. The research concludes that there is knowledge gap in our secondary school educational system concerning climate change. Therefore, it recommends capacity building in science-teaching education curriculum for knowledge-based sustainable development.","PeriodicalId":10219,"journal":{"name":"Civil and environmental research","volume":"8 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86204969","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

A Study of Consumers’ Complaints against Real Estate Agents in Lagos Metropolis, Nigeria 尼日利亚拉各斯大都市区消费者对房地产中介的投诉研究

Civil and environmental research Pub Date : 2021-07-01 DOI: 10.7176/cer/13-4-05

Funmilayo Moyinola

{"title":"A Study of Consumers’ Complaints against Real Estate Agents in Lagos Metropolis, Nigeria","authors":"Funmilayo Moyinola","doi":"10.7176/cer/13-4-05","DOIUrl":"https://doi.org/10.7176/cer/13-4-05","url":null,"abstract":"The study examined consumers’ complaints against real estate agents in Lagos Metropolis, Nigeria with a view to providing information that could ensure effective service orientation and high consumers’ satisfaction. Data were elicited from real estate agents and consumers in the study area through self-administered questionnaire and analyzed with the use of frequency distribution, percentages and mean rating. The study found some level of dissatisfaction as 35.3% representing 61 of the real estate agency consumers were dissatisfied with real estate agency related services. 30.1% of the respondents objected to the possibility of repeat business with their real estate agent while 33% rejected the possibility of recommending their agents to others. The most common complaint against real estate agents was ‘fee levels too high’ as reported by 81 respondents representing 31% of the study population. The study also revealed that real estate agency consumers complained about communication problems, over pricing of property, agents providing wrong information, agents not delivering what was required, agents pressurizing customers, delays, deadlines not met, galumphing, agents providing wrong information, mismanagement of the property in their care etc. Therefore real estate service consumers’ complaints must be thoroughly attended to as these may lead to consumers’ dissatisfaction. Real estate agents must ensure that customer service remains high so as to experience consumers’ satisfaction, retention and successful businesses.","PeriodicalId":10219,"journal":{"name":"Civil and environmental research","volume":"77 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88868474","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

Assessment of Water Supply and Sanitation in Bishan Guracha Sub-City in West Arsi Zone 西阿尔西地区璧山古拉察子城市供水卫生评价

Civil and environmental research Pub Date : 2021-06-01 DOI: 10.7176/cer/13-4-03

引用次数: 0

Determinants of Urban Poverty in Ethiopia: The Case of Jimma Town, South West Ethiopia 埃塞俄比亚城市贫困的决定因素:以埃塞俄比亚西南部吉玛镇为例

Civil and environmental research Pub Date : 2021-06-01 DOI: 10.7176/cer/13-4-01

引用次数: 0

Delineation of Wellhead Protection Areas: Methodology and Application 井口保护区的划定:方法与应用

Civil and environmental research Pub Date : 2021-06-01 DOI: 10.7176/cer/13-4-04

引用次数: 0

Selection of Best Available Wastewater Treatment Technology: Case of Bahir Dar University, Gish Abay Campus, Ethiopia 最佳可用废水处理技术的选择:以埃塞俄比亚巴希尔达尔大学吉什阿贝校区为例

Civil and environmental research Pub Date : 2021-06-01 DOI: 10.7176/cer/13-4-02

引用次数: 0

Electrical and Mechanical Effects of Carbon Powder in F and C Class Fly Ash Reinforced Mortars 碳粉在F级和C级粉煤灰增强砂浆中的电气和机械效应

Civil and environmental research Pub Date : 2021-01-01 DOI: 10.7176/cer/13-2-02

Hacer Uzunalioglu, Adem Ahiskali, H. Çağlar, S. Yazıcıoğlu

{"title":"Electrical and Mechanical Effects of Carbon Powder in F and C Class Fly Ash Reinforced Mortars","authors":"Hacer Uzunalioglu, Adem Ahiskali, H. Çağlar, S. Yazıcıoğlu","doi":"10.7176/cer/13-2-02","DOIUrl":"https://doi.org/10.7176/cer/13-2-02","url":null,"abstract":"This study was carried out to investigate the effects of carbon powder on the electrical conductivity and mechanical properties of fly ash reinforced mortars used as mineral additives. Samples were created by replacing CEM I 42.5 R cement, water and Cen standard sand with 0.5%, 1%, 3% carbon powder by weight. Class F and Class C fly ash were added separately at the rate of 10% and 20% by weight of cement to the formed carbon dust series. 20 different series were created with the reference sample. Electrical resistivity measurements were made to the oven dry and natural humid conditions of the samples that completed their 7,28 and 56 days curing period. The physical properties of the samples were determined and bending and compressive strength tests were made. The results obtained were evaluated and it was observed that with the increase of the carbon dust ratio compared to the reference sample, the electrical conductivity ratio increased, but the conductivity decreased depending on the time. It has been observed that the F class fly ash combination series are more conductive than the C class combination series. It was observed that the compressive and tensile strength values of F and C class fly ash carbon dust free samples increased with time. Carbon dust has been shown to increase compressive strength in fly ashless series. There was an increase in the 56th day reading in the tensile strength. It was observed that F class increased tensile and compressive strength in fly ash and carbon dust combination series. ash, C class fly ash, Electrical conductivity.","PeriodicalId":10219,"journal":{"name":"Civil and environmental research","volume":"116 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78245872","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

An Experimental and Analytical Study of the Distribution of Heat in Concrete Columns 混凝土柱内热分布的实验与分析研究

Civil and environmental research Pub Date : 2021-01-01 DOI: 10.7176/CER/13-1-01

M. Takla

{"title":"An Experimental and Analytical Study of the Distribution of Heat in Concrete Columns","authors":"M. Takla","doi":"10.7176/CER/13-1-01","DOIUrl":"https://doi.org/10.7176/CER/13-1-01","url":null,"abstract":"Fire is one of the most devastating disasters that have caused human damage, prompting researchers to conduct numerous studies on the behavior of fire-prone elements and take action to minimize damage. With the development of computer simulation theories, it is possible to study the behavior of structures under the influence of different loads (static, dynamic, thermal ... etc), and this leads to saving time, effort and money cost instead of performing laboratory experiments. Thermal loads are considered one of the most dangerous loads to which concrete structures are exposed. Hence it is very important to know the thermal distribution in the cross section of the element exposed to high temperature. Whereas, by knowing the thermal distribution, the designed load and the expected failure load of the structural element can be calculated and thus take the necessary measures to reduce the fire risk as much as possible. In this research, an experimental and analytical study was conducted on models of reinforced concrete columns, where thermocouple were used in different places to monitor the temperature at the specified points, The experimental thermal distribution was compared with the analytical results of the ANSYS Workbench program. The analytical results showed a great accuracy compared to the experimental results. Consequently, an analytical model was simulated to simulate the experimental, through which it is possible to know the thermal distribution of the model. Keywords : thermal distribution, thermal analysis, thermocouple, ANSYS Workbench. DOI: 10.7176/CER/13-1-01 Publication date: January 31 st 2021","PeriodicalId":10219,"journal":{"name":"Civil and environmental research","volume":"452 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82928789","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