scholarly journals Bond behaviour of thin concrete overlays for maintenance of concrete pavements

2018 ◽  
Vol 199 ◽  
pp. 08005
Author(s):  
Rolf Breitenbücher ◽  
Christoph Schulte-Schrepping ◽  
Sebastian Kunz
Keyword(s):  
Large Scale ◽  
Concrete Beams ◽  
Lower Layer ◽  
Small Scale ◽  
Concrete Pavements ◽  
Bond Behaviour ◽  
Climate Conditions ◽  
Concrete Overlays ◽  
Maintenance Techniques ◽  
Base Course

Concrete pavements are exposed to a number of stresses during their service life, mostly resulting from traffic and climate conditions. In consideration of the continuously rising traffic volume, the durability requirements of concrete pavements become more and more significant. In this context, maintenance and repair become increasingly important. Small-scale repairs like spalling at edges up to the replacement of whole slabs are proven in several cases. In contrast, large-scale maintenance techniques for partial repairs of whole pavement sections are not available, yet. If the upper layer concrete is deteriorated, while the lower layer and the base course are still intact, the whole pavement needs to be replaced, due to a lack of alternatives. Therefore new maintenance techniques like the application of concrete overlays are needed for an economic rehabilitation and the prevention of an unnecessarily long traffic disruption by time-consuming maintenance of complete pavements. The relevant questions how a durable bond between old and new concrete can be ensured and which parameters affect this bond, were investigated in representative studies on large-scale concrete beams with a thin concrete overlay on existing concrete.

Thin Concrete Overlays with Carbon Reinforcement

2021 ◽  
Author(s):  
Julia Neumann ◽  
Kristina Farwig ◽  
Rolf Breitenbücher ◽  
Manfred Curbach
Keyword(s):  
Large Scale ◽  
Plain Concrete ◽  
Bottom Layer ◽  
Concrete Pavements ◽  
Flexural Stress ◽  
Bond Behaviour ◽  
Concrete Overlays ◽  
Flexural Tensile Strength ◽  
Major Disadvantage ◽  
The One

In many countries like Germany, concrete pavements are normally built as Jointed Plain Concrete Pavements (JPCP). Due to a lack of alternatives, maintenance of concrete pavements usually requires a replacement of the whole pavement structure, which is labour- and resource-intensive. Therefore, new techniques like the application of thin concrete overlays as a partial repair of deteriorated concrete pavements have been developed. As a major disadvantage of such overlays, the existing joints in the retained concrete bottom-layer have to be transferred in the overlay in order to avoid reflection cracking. When using non-corrosive carbon-textile reinforcement in such concrete overlays, cracks might be distributed more finely, enabling jointless repairs while keeping a thin repair layer. In addition, the bond behaviour between the retained concrete and the applied concrete overlay as well as between the concrete overlay and the textile reinforcement is crucial for a successful repair. In this paper, the basic principles and feasibility of such a repair method are examined. On the one hand, the decisive influencing variables and parameters such as bond behaviour between the concrete layers and the cracking behaviour of the overlay are pointed out and discussed. On the other hand, the evaluated laboratory tests carried out are presented. These include large-scale beams built with an overlay on top of a retained concrete layer, which were subjected to cyclic flexural stress and to a subsequent detailed investigation of the bond behaviour and durability. Furthermore, the crack formation in the overlay was determined by means of tensile and flexural tensile strength tests.

scholarly journals Design and Fabrication of Semi Automatic Coconut Copra Electric Dryer

2020 ◽  
Vol 9 (6) ◽  
pp. 637-641
Keyword(s):  
Large Scale ◽  
Weather Condition ◽  
Major Product ◽  
Small Scale ◽  
Climate Conditions ◽  
Adverse Weather Condition ◽  
Adverse Weather ◽  
Individual Household ◽  
High Initial Cost ◽  
Small Scale Farmers

In India Coconut is the major plantation crop in the states of Tamilnadu, kerala, Karnataka, Kongan region of Maharastra and Andaman and Nicobar Islands for entire seasons. Copra is the major product from the coconut cultivation earning higher income of small and medium livelihoods. The approval of copra quality is mainly based on how well the copra got dried. Open drying or other conventional methods is the major process of making copra. In adverse weather condition, rainy season the drying process will be very challenging. Many dryers are made and used currently was affordable to medium and large scale copra producers. Those dryers also having limitations in size, high initial cost and nature dependency. There is very few attempt made for Small and individual household copra producers. This paper mainly focuses on how to dry-up the copra in all climate conditions. An electric handy dryer is designed to dry up the coconut copra and other grains. It mainly helps the small scale farmers as a handy dryer unit to dry-up the copra, those who are using coconut as a way of income. Based on the experiments conducted the electric dryer removed high moisture content than forced convection and direct sun dryers.

Small-Scale Science to Large-Scale Profession

2000 ◽  
Vol 45 (4) ◽  
pp. 396-398
Author(s):  
Roger Smith
Keyword(s):  
Large Scale ◽  
Small Scale

Development of Physics Learning Module Based on Guided Inquiry with Light Wave Material in Class XI of Senior High School

2020 ◽  
Vol 1 (1) ◽  
pp. 1-10
Author(s):  
Evi Rahmawati ◽  
Irnin Agustina Dwi Astuti ◽  
N Nurhayati
Keyword(s):  
Large Scale ◽  
Learning Strategy ◽  
Student Response ◽  
Average Score ◽  
Small Scale ◽  
Design Development ◽  
Teacher Response ◽  
Student Responses ◽  
Analysis Design ◽  
Scientific Skills

IPA Integrated is a place for students to study themselves and the surrounding environment applied in daily life. Integrated IPA Learning provides a direct experience to students through the use and development of scientific skills and attitudes. The importance of integrated IPA requires to pack learning well, integrated IPA integration with the preparation of modules combined with learning strategy can maximize the learning process in school. In SMP 209 Jakarta, the value of the integrated IPA is obtained from 34 students there are 10 students completed and 24 students are not complete because they get the value below the KKM of 68. This research is a development study with the development model of ADDIE (Analysis, Design, Development, Implementation, and Evaluation). The use of KPS-based integrated IPA modules (Science Process sSkills) on the theme of rainbow phenomenon obtained by media expert validation results with an average score of 84.38%, average material expert 82.18%, average linguist 75.37%. So the average of all aspects obtained by 80.55% is worth using and tested to students. The results of the teacher response obtained 88.69% value with excellent criteria. Student responses on a small scale acquired an average score of 85.19% with highly agreed criteria and on the large-scale student response gained a yield of 86.44% with very agreed criteria. So the module can be concluded receiving a good response by the teacher and students.

Planetary gentrification and urban (re)development

2019 ◽  
Vol 61 (1) ◽  
pp. 5-13 ◽  
Author(s):  
Loretta Lees
Keyword(s):  
Low Income ◽  
Policy Making ◽  
Large Scale ◽  
Urban Redevelopment ◽  
Urban Transformation ◽  
Small Scale ◽  
Income Groups ◽  
Low Income Groups

Abstract Gentrification is no-longer, if it ever was, a small scale process of urban transformation. Gentrification globally is more often practised as large scale urban redevelopment. It is state-led or state-induced. The results are clear – the displacement and disenfranchisement of low income groups in favour of wealthier in-movers. So, why has gentrification come to dominate policy making worldwide and what can be done about it?

AGRICULTURAL PRODUCTION OF CA DONG PEOPLE IN RESETTLEMENT AREA OF TRANH RIVER HYDROPOWER NUMBER 2: CURRENT SITUATION AND IMPACT FACTORS

2020 ◽  
Vol 9 (2) ◽  
Author(s):  
Bùi Thị Bích Lan
Keyword(s):  
Social Relations ◽  
Agricultural Production ◽  
Large Scale ◽  
Transition Process ◽  
Impact Factors ◽  
Small Scale ◽  
Scale Production ◽  
Technical Application ◽  
Production Models ◽  
Role Of The State

In Vietnam, the construction of hydropower projects has contributed significantly in the cause of industrialization and modernization of the country. The place where hydropower projects are built is mostly inhabited by ethnic minorities - communities that rely primarily on land, a very important source of livelihood security. In the context of the lack of common productive land in resettlement areas, the orientation for agricultural production is to promote indigenous knowledge combined with increasing scientific and technical application; shifting from small-scale production practices to large-scale commodity production. However, the research results of this article show that many obstacles in the transition process are being posed such as limitations on natural resources, traditional production thinking or the suitability and effectiveness of scientific - technical application models. When agricultural production does not ensure food security, a number of implications for people’s lives are increasingly evident, such as poverty, preserving cultural identity, social relations and resource protection. Since then, it has set the role of the State in researching and building appropriate agricultural production models to exploit local strengths and ensure sustainability.

Managing the impacts of mining on Ghana’s water resources from a legal perspective

2018 ◽  
Vol 1 (3) ◽  
pp. 156-165 ◽  
Author(s):  
Nasirudeen Abdul Fatawu
Keyword(s):  
Surface Water ◽  
Water Resources ◽  
Environmental Protection Agency ◽  
Large Scale ◽  
Small Scale ◽  
Mining Activities ◽  
Protection Agency ◽  
Environmental Laws ◽  
Mining Areas ◽  
Legal Perspective

Recent floods in Ghana are largely blamed on mining activities. Not only are lives lost through these floods, farms andproperties are destroyed as a result. Water resources are diverted, polluted and impounded upon by both large-scale minersand small-scale miners. Although these activities are largely blamed on behavioural attitudes that need to be changed, thereare legal dimensions that should be addressed as well. Coincidentally, a great proportion of the water resources of Ghana arewithin these mining areas thus the continual pollution of these surface water sources is a serious threat to the environmentand the development of the country as a whole. The environmental laws need to be oriented properly with adequate sanctionsto tackle the impacts mining has on water resources. The Environmental Impact Assessment (EIA) procedure needs to bestreamlined and undertaken by the Environmental Protection Agency (EPA) and not the company itself.

RANCANG BANGUN PERANGKAT EKSPERIMENTASI PROSES PIROLISIS BIOMASA GELOMBANG MIKRO

2013 ◽  
Vol 14 (2) ◽  
Author(s):  
Noor Fachrizal
Keyword(s):  
Large Scale ◽  
Continuous Model ◽  
Biomass Energy ◽  
Scale Model ◽  
Small Scale ◽  
Laboratory Apparatus ◽  
Liquid Form ◽  
Large Scale Model ◽  
Bio Oil ◽  
Pyrolysis Of Biomass

Biomass such as agriculture waste and urban waste are enormous potency as energy resources instead of enviromental problem. organic waste can be converted into energy in the form of liquid fuel, solid, and syngas by using of pyrolysis technique. Pyrolysis process can yield higher liquid form when the process can be drifted into fast and flash response. It can be solved by using microwave heating method. This research is started from developing an experimentation laboratory apparatus of microwave-assisted pyrolysis of biomass energy conversion system, and conducting preliminary experiments for gaining the proof that this method can be established for driving the process properly and safely. Modifying commercial oven into laboratory apparatus has been done, it works safely, and initial experiments have been carried out, process yields bio-oil and charcoal shortly, several parameters are achieved. Some further experiments are still needed for more detail parameters. Theresults may be used to design small-scale continuous model of productionsystem, which then can be developed into large-scale model that applicable for comercial use.

Mapping global water projects: improving access to donor investment information on the web

Water Policy ◽  
2003 ◽  
Vol 5 (3) ◽  
pp. 203-212
Author(s):  
J. Lisa Jorgensona
Keyword(s):  
Water Resources ◽  
Web Sites ◽  
Large Scale ◽  
Technical Assistance ◽  
Water Withdrawal ◽  
Small Scale ◽  
Water Projects ◽  
Essential Information ◽  
Water Project ◽  
The Web

This paper discusses a series of discusses how web sites now report international water project information, and maps the combined donor investment in more than 6000 water projects, active since 1995. The maps show donor investment:  • has addressed water scarcity,  • has improved access to improvised water resources,  • correlates with growth in GDP,  • appears to show a correlation with growth in net private capital flow,  • does NOT appear to correlate with growth in GNI. Evaluation indicates problems in the combined water project portfolios for major donor organizations: •difficulties in grouping projects over differing Sector classifications, food security, or agriculture/irrigation is the most difficult.  • inability to map donor projects at the country or river basin level because 60% of the donor projects include no location data (town, province, watershed) in the title or abstracts available on the web sites.  • no means to identify donor projects with utilization of water resources from training or technical assistance.  • no information of the source of water (river, aquifer, rainwater catchment).  • an identifiable quantity of water (withdrawal amounts, or increased water efficiency) is not provided.  • differentiation between large scale verses small scale projects. Recommendation: Major donors need to look at how the web harvests and combines their information, and look at ways to agree on a standard template for project titles to include more essential information. The Japanese (JICA) and the Asian Development Bank provide good models.

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