scholarly journals Capillary Characteristics and Applicability of Coal Bottom Ash as an Anti-Capillary Material for Coastal Constructions

Author(s):  
Nguyen Ngoc Truc ◽  
Nguyen Van Hoang ◽  
Do Ngoc Ha ◽  
Nguyen Thao Ly

Utilization of Coal bottom ash (CBA) as well as finding the solutions to prevent saline intrusion, meeting the needs of coastal infrastructure development have been considered by the authors of the article for a long time. In this study, the authors focused on analyzing capillary characteristics in order to find a suitable group of CBA particles, which can be applied in the design of foundations with the high ability in restricting or preventing the effects of salt in saline groundwater. The obtained results show that (1) The capillary height is inversely proportional to the particle size: the larger the particle, the smaller the capillary height and vice versa. The CBA group with a diameter of 2.0 - 5.0 mm has an average capillary height around 3.33 cm; a group of particles size of 1.0 - 2.0 mm is 7.16 cm; a group of particles size of 0.5 – 1.0 mm is 23.36 cm. Meanwhile, the group of particles size of 0.1 - 0.5 mm is 31.26 cm. (2) The capillary height is inversely proportional to the salt concentration in the capillary solution: the maximum capillary height exhibits with the lowest capillary solution salinity ~ 0.0 g/L, whereas it reaches minimum value when salinity approximate 33.0 g/L. Thus, CBA with the same particle size of gravel (diameter from 2.0 to 5.0 mm) is able to block capillary flow. This study forms the basis for the design solutions of anti-saline foundation, especially in the context of climate change and sea-level rise.

2015 ◽  
Vol 13 ◽  
pp. 210-215 ◽  
Author(s):  
Olimpia Ghermec ◽  
Ionela Gabriela Bucse ◽  
Mariana Ciobanu

Human existence is dependent on the consumption of electricity and of thermal energy. One of the environmental problems is represented by the particulate matter with the diameter of less than 2.5 mm derived from combustion of coal. In order to find solutions to reduce emissions at source, the particle size distribution of the coal bottom ash after removing it from the steam boiler of the large combustion plant from Romag Halanga in Drobeta Turnu – Severin area was determined. Dry particle size distribution shows that the major fraction is one that has a particle size of 125 μm. Particle size distribution in the smallest size fraction was performed with laser diffraction particle size analyzer Brookhaven 90 Plus Nanoparticle Size Analyzer. Particle size distribution shows that in the composition of the coal bottom ash were found particles with nanometric dimensions.


2020 ◽  
Vol 4 (1) ◽  
pp. 19-26
Author(s):  
Ninis Hadi Haryanti, Henry Wardhana, Suryajaya

Abstrak – Pada umumnya ukuran partikel yang digunakan dalam pembuatan briket bervariasi antara 12 -100 mesh. Pada penelitian ini, ukuran partikel yang digunakan adalah 250 mesh (59,4 µm). Dilakukan kajian analisis proksimat briket terhadap variasi tekanan pencetakan. Briket dibuat dari campuran limbah industri arang kayu alaban dan abu dasar batubara. Kedua bahan dalam bentuk serbuk yang lolos pada saringan 250 mesh.Ukuran partikel yang lebih kecil diharapkan menghasilkan briket yang lebih baik dan tidak  rapuh serta dapat digunakan sebagai bahan bakar alternatif untuk rumah tangga maupun industri dan penggunaan bahan limbah diharapkan membantu pemecahan permasalahan lingkungan. Variasi tekanan yang digunakan adalah 150, 200, 250, 300, dan 350 kg/cm2. Komposisi campuran limbah arang kayu alaban dan abu dasar batubara dengan rasio 90%:10%, sedangkan perekat tepung kanji 5%. Briket dibuat dalam bentuk silinder berukuran 2 × 2 cm. Briket yang sudah dicetak dikeringkan dalam oven pada suhu 120°C selama 4 jam dan didinginkan pada suhu ruang selama 24 jam. Dari hasil uji didapatkan Kadar Air (3,831-5,892) %; Kadar Abu (7,178-10,507) %; Nilai Kalori (5607,467-5732,033) cal/g; Densitas (0,688-0,769) g/cm3; dan Porositas (46,025-47,592) %. Berdasarkan hasil uji, dapat disimpulkan bahwa semakin tinggi nilai tekanan, kadar air, kadar abu, dan porositas akan menurun, sedangkan nilai kalori mencapai nilai tertinggi pada tekanan 200 kg/cm2 kemudian cenderung mengalami penurunan. Direkomendasikan tekanan yang diberikan pada saat pembuatan briket adalah 200 kg/cm2.Kata kunci: abu dasar batubara, arang kayu alaban, briket, tekanan pencetakan, ukuran partikelAbstract – In general, the particle size used in making briquettes were varied in the range of 12 -100 mesh. In this study, the particle size used was 250 meshs (59.4 µm). The effect of press variations to proximate analysis of briquette will be conducted. Briquette was made from a mixture of alaban wood charcoal industrial waste and coal bottom ash. Both materials were crushed in the form of powder passing 250 meshs sieve. The smaller particle size is expected to produce better and less brittle briquettes and could be used as alternative fuels for households and industries, while the use of waste materials is expected to help solve environmental problems. Pressure variations used were 150, 200, 250, 300, and 350 kg/cm2. The composition of the mixture of alaban wood charcoal waste and coal bottom ash wasin ratio 90%: 10%, while starch adhesive of 5% was added. Briquettes were made in the form of cylinders (2 × 2 cm in size). Briquettes were dried in an oven at 120°C for 4 hours and cooled at room temperature for 24 hours. The results obtained were Moisture Content (3,831-5,892)%; Ash Content (7,178-10,507)%; Heating Value (5607,467-5732,033) cal / g; Density (0.688-0.769) g/cm3; and Porosity (46,025-47,592)%. Based on the results, it could be concluded that as the pressure increased, water content, ash content, and porosity were decreased. The calorie value reaches the highest value at a pressure of 200 kg/cm2 then tends to decrease. It is recommended that the pressure applied at the time of briquette making is 200 kg/cm2.Key words: coal bottom ash, alaban charcoal, briquettes, pressure, particle size


2019 ◽  
Vol 15 (2) ◽  
pp. 125-135
Author(s):  
Tatiana S. Minaeva ◽  
Sergey S. Gulyaev

Introduction. The organization of transport links and the bridge building in cities located on the banks of wide rivers has always been one of the most important tasks of the local administration. The study of the history of bridge building allows not only to trace the process of modernization of different regions of the country, but also to help in solving similar problems of our time. Nevertheless, the history of Russian bridge building is poorly studied. The purpose of the article is to determine the characteristics and features of the organization of bridge building in big cities of the European North of Russia as a way to solve one of the problems of urban infrastructure in the early XX century. Materials and Methods. The sources for this study are the documents of the State archive of the Arkhangelsk region, published documents on the history of Vologda, articles in the local periodicals of the early XX century. The analysis of the studied problem used a systematic approach, the method of economic analysis, historical and historical-comparative methods. Results and Discussion. The building of permanent bridges was a need for the development of Arkhangelsk and Vologda. In Vologda the two wooden bridges were built in the middle of XIX century on city funds and in the future these bridges were repaired or rebuilt. The Arkhangelsk city authorities did not hurry to solve a problem of city infrastructure by own efforts and a long time they used the floating bridge. The lack of experience in the building of large bridges and the desire to save money led to the rapid destruction of the first permanent bridge in Arkhangelsk. Conclusion. The Development of trade and industry in cities of the European North of Russia, such as Arkhangelsk and Vologda, led to the expansion of their territory and the emergence over time, the so-called third parts of the cities. Despite the comparable size of the population of the districts located across the river, the process of connecting them with bridges to the rest of the city went at different rates, which depended on the attitude of the local administration to the problem of urban infrastructure.


J ◽  
2021 ◽  
Vol 4 (3) ◽  
pp. 223-232
Author(s):  
Esperanza Menéndez ◽  
Cristina Argiz ◽  
Miguel Ángel Sanjuán

Ground coal bottom ash is considered a novel material when used in common cement production as a blended cement. This new application must be evaluated by means of the study of its pozzolanic properties. Coal bottom ash, in some countries, is being used as a replacement for natural sand, but in some others, it is disposed of in a landfill, leading thus to environmental problems. The pozzolanic properties of ground coal bottom ash and coal fly ash cements were investigated in order to assess their pozzolanic performance. Proportions of coal fly ash and ground coal bottom ash in the mixes were 100:0, 90:10, 80:20, 50:50, 0:100. Next, multicomponent cements were formulated using 10%, 25% or 35% of ashes. In general, the pozzolanic performance of the ground coal bottom ash is quite similar to that of the coal fly ash. As expected, the pozzolanic reaction of both of them proceeds slowly at early ages, but the reaction rate increases over time. Ground coal bottom ash is a promising novel material with pozzolanic properties which are comparable to that of coal fly ashes. Then, coal bottom ash subjected to an adequate mechanical grinding is suitable to be used to produce common coal-ash cements.


2021 ◽  
Vol 13 (14) ◽  
pp. 8031
Author(s):  
Syakirah Afiza Mohammed ◽  
Suhana Koting ◽  
Herda Yati Binti Katman ◽  
Ali Mohammed Babalghaith ◽  
Muhamad Fazly Abdul Patah ◽  
...  

One effective method to minimize the increasing cost in the construction industry is by using coal bottom ash waste as a substitute material. The high volume of coal bottom ash waste generated each year and the improper disposal methods have raised a grave pollution concern because of the harmful impact of the waste on the environment and human health. Recycling coal bottom ash is an effective way to reduce the problems associated with its disposal. This paper reviews the current physical and chemical and utilization of coal bottom ash as a substitute material in the construction industry. The main objective of this review is to highlight the potential of recycling bottom ash in the field of civil construction. This review encourages and promotes effective recycling of coal bottom ash and identifies the vast range of coal bottom ash applications in the construction industry.


Sign in / Sign up

Export Citation Format

Share Document