scholarly journals Recycling of Coal Ash in Concrete as a Partial Cementitious Resource

Resources ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 99 ◽  
Author(s):  
Sajjad Ali Mangi ◽  
Mohd Haziman Wan Ibrahim ◽  
Norwati Jamaluddin ◽  
Mohd Fadzil Arshad ◽  
Sri Wiwoho Mudjanarko

Concrete construction offers a great opportunity to replace the cement with a coal-based power plant waste—known as coal bottom ash (CBA)—which offers great environmental and technical benefits. These are significant in sustainable concrete construction. This study aims to recycle CBA in concrete and evaluate its particle fineness influence on workability, compressive and tensile strength of concrete. In this study, a total of 120 specimens were prepared, in which ground CBA with a different fineness was used as a partial cement replacement of 0% to 30% the weight of cement. It was noticed that workability was decreased due to an increased amount of ground CBA, because it absorbed more water in the concrete mix. The growth in the compressive and tensile strength of concrete with ground CBA was not significant at the early ages. At 28 days, a targeted compressive strength of 35 MPa was achieved with the 10% ground CBA. However, it required a longer time to achieve a 44.5 MPa strength of control mix. This shows that the pozzolanic reaction was not initiated up to 28 days. It was experimentally explored that 10% ground CBA—having particle fineness around 65% to 75% and passed through 63 µm sieve—could achieve the adequate compressive and tensile strength of concrete. This study confirmed that the particle fineness of cement replacement materials has a significant influence on strength performance of concrete.

2019 ◽  
Vol 5 (1) ◽  
pp. 74 ◽  
Author(s):  
Ashfaque Ahmed Jhatial ◽  
Wan Inn Goh ◽  
Kim Hung Mo ◽  
Samiullah Sohu ◽  
Imtiaz Ali Bhatti

Concrete which is widely used material in the construction industry, has a carbon footprint. Approximately 10% of global Carbon Dioxide (CO2) gas is emitted during the production of cement which is vital ingredient of concrete. The increase in production of cement affects global warming and climate change. Therefore, many have attempts have been made to develop green and sustainable concrete by utilizing different waste materials. With the utilization of waste materials as cement replacement, the CO2 gas emissions can be reduced as well as resolve the environmental issues that the inhabitants face during the disposal of such waste materials. This paper reviews the potential and innovative utilization of Rice Husk Ash (RHA) and Eggshells as partial cement replacement to develop green concrete. RHA which is rich in silica and eggshells contain identical amount of calcium oxide as cement, when finely grinded and used together as partial cement replacement, can trigger a pozzolanic reaction, in which silica reacts with calcium oxide resulting in the formation of calcium silicates which are responsible for achieving higher strengths.


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.


2020 ◽  
Vol 6 (1) ◽  
pp. 13 ◽  
Author(s):  
Noraziela Syahira Baco ◽  
Shahiron Shahidan ◽  
Sharifah Salwa Mohd Zuki ◽  
Noorwirdawati Ali ◽  
Mohamad Azim Mohammad Azmi

Coal Bottom Ash (CBA) is a mineral by-product of thermal power plants obtained from the combustion of coal. In many countries, CBA wastes are identified as hazardous materials. The utilization of CBA can help in alleviating environmental problems; thus, this research was carried out to explore the possibility of its use as cement replacement in concrete manufacturing. Presently, In Malaysia, research that concerns about the use of CBA as cement replacement is very limited. Therefore, this study was aimed to investigate the properties of CBA as cement replacement and to identify the optimum percentage of untreated CBA as cement replacement. The CBA used in this study were taken from the Tanjung Bin power plant. In this research, the amount of CBA in the concrete mixture varied from 20% to 40% to replace cement. The properties of concrete containing CBA as cement replacement was examined through slump test, sieve analysis, concrete compressive strength test and splitting tensile strength test. The compressive strength test and splitting tensile strength test were performed at 7 and 28 days of curing time. Based on this research, it can be concluded that the optimum percentage of CBA as cement replacement is 25% for a curing time of both 7 and 28 days with the concrete compression strength of 45.2 MPa and 54.6 MPa, respectively. Besides, the optimum percentage for tensile strength is also at 25% CBA for a curing period of both 7 and 28 days with the tensile strength of 2.91 MPa and 3.28 MPa, respectively. 


Author(s):  
Vinayak S. ◽  
Akshay Y. Bhovi

This study examined the potential use of sugarcane bagasse ash as a partial cement replacement material and treated domestic wastewater was made for the mixing and curing of concrete. The bagasse ash was collected from the Malaprabha sugar industry, Belagavi, and the treated wastewater was collected from Dr. Prabhakar Kore Hospital & MRC, Belagavi. The work involved the design of M20 grade concrete with w/c ratio of 0.40 and also chemical admixture was made used. The study evaluated the slump, compressive strength, and split tensile strength of concrete with different cement replacement ratios. An equal number of cubes and cylinders were casted and were cured in both tap water and treated wastewater separately for a curing period of 28 days and 56 days. The compressive and tensile strength results were obtained after 28 days of curing period for cubes and cylinders. Results show that replacement of cement with bagasse ash and curing them under treated wastewater obtained good results, which supports waste minimization and utilization. The blended concrete compressive strength results also indicate that the easing of sulphate attack will be drastically reduced when cured under treated wastewater.


2017 ◽  
Vol 68 (10) ◽  
pp. 2367-2372 ◽  
Author(s):  
Ng Hooi Jun ◽  
Mirabela Georgiana Minciuna ◽  
Mohd Mustafa Al Bakri Abdullah ◽  
Tan Soo Jin ◽  
Andrei Victor Sandu ◽  
...  

Manufacturing of Portland cement consists of high volume of natural aggregates which depleted rapidly in today construction field. New substitutable material such as bottom ash replace and target for comparable properties with hydraulic or pozzolanic properties as Portland cement. This study investigates the replacement of different sizes of bottom ash into Portland cement by reducing the content of Portland cement and examined the mechanism between bottom ash (BA) and Portland cement. A cement composite developed by 10% replacement with 1, 7, 14, and 28 days of curing and exhibited excellent mechanical strength on day 28 (34.23 MPa) with 63 mm BA. The porous structure of BA results in lower density as the fineness particles size contains high specific surface area and consume high quantity of water. The morphology, mineralogical, and ternary phase analysis showed that pozzolanic reaction of bottom ash does not alter but complements and integrates the cement hydration process which facilitate effectively the potential of bottom ash to act as construction material.


2019 ◽  
Vol 303 ◽  
pp. 05001
Author(s):  
Mónica Bedoya ◽  
Federico Rivera ◽  
María Rico ◽  
David Vélez ◽  
Andrés Urrego ◽  
...  

It is clear that construction and demolition wastes (CDW) are constantly increasing throughout the world and these wastes can be used effectively to minimize the consumption of natural resources in the manufacture of more sustainable concrete. The CDW occupy an important segment of world waste production and its generation reached approximately 3 billion tons in 2012 in 40 countries [1]. Although this topic has been studied in the world, it is still valid for the reuse of waste that is constantly increasing, and although in many countries there are already examples of its use this type of concrete in Colombia and in the Medellìn city lacks applications. This project proposes the application of a sustainable concrete made with CDW and coal ash in the Medellín city for its implementation in the construction of urban furniture. A university community diagnosis of the needs in terms of furnishing was made. With the design reached, a modular chair was proposed to enable spaces within the university. The mechanical characteristics of the concrete and the design of the chair are evaluated and a simulation is done through finite elements to evaluate the viability of the proposed concrete, finding that with these properties is possible to manufacture durable and sustainable furniture that serves as an example for the application of sustainable materials


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