Effects of Grinding Process on the Properties of the Coal Bottom Ash and Cement Paste

Abstract

The grinding process is necessary to convert original coal bottom ash (CBA) into a powder form. The aim of this study is to evaluate the grinding process effects on physical properties of CBA, it influences on consistency and setting time of cement paste and to predict it potentiality based on chemical characteristics to reduce the alkali-silica reaction (ASR) in concrete. The CBA is the by-product of coal based thermal power plant. Due to high production of electricity in Malaysia, the excess amount of CBA has been produced annually and it causes the environmental problems. Therefore, it is necessary to come up with advanced solutions for that pollution. This study considered the different grinding periods i.e. 2, 10, 20, and 40hrs as to produce different particle fineness. It was perceived through the laboratory findings that the more the grinding period, finer the particle sizes. Besides that, cement paste with 10, 20 and 30% of ground CBA as a substitute of ordinary portland cement (OPC) by weight was prepared, it was observed that the consistency of OPC paste increases with the addition of ground CBA. Moreover, initial and final setting time of cement paste containing ground CBA was observed higher than the OPC paste. Hence, based on experimental analysis and energy efficiency scenario, grinding period of 20hrs with specific surface area 3835.75 cm 2 /g is suggested for the future studies.

Use of Marble Powder and Tile Powder as Cementitious Materials in Concrete

“…Many methods have been proposed on the use of industrial or agricultural waste as partial cement substitutes [10]. Industrial waste includes waste from marble powder, blast furnace slag, tile powder [11], fly ash and silica fume, while agricultural waste includes rice husk ash [12,13], corn cob ash [14], wheat straw ash, ground coal bottom ash [15,16], coconut waste, and bagasse ash, which are used to replace partially the cement in concrete [17,18]. The use of these wastes as substitutes for cement not only reduces the cost of concrete, but it also minimizes the negative environmental impacts associated to their disposal, and the release of CO 2 during cement production [19,20].…”

Recycling of Coal Ash in Concrete as a Partial Cementitious Resource

“…But they did not consider the different fineness (different grinding periods). Moreso, it was previously suggested by Zhao, et al [11], Jaya, et al [12] and Mangi, et al [13] that the addition of fine ground supplementary cementing materials (SCMs) could enhance the strength of concrete. It was previously stated that SCMs-made from natural or waste materials-has been given serious attention to the development of composite cement for ecological, economic, and multi-quality reasons [14].…”

Preliminary Investigation of Thermal Behavior of Lightweight Foamed Concrete Incorporating Palm Oil Fuel Ash and Eggshell Powder

“…POFA was collected from nearby palm oil mill, while the eggshells were collected from local restaurants and bakeries in the vicinity. The fineness of cement influences the strength of concrete [21] and since waste materials such as POFA and ESP are being used as a cement replacement, both waste materials need to have adequate fineness [22]. Therefore, POFA was first sieved using 300 µm in order to remove any impurities and then oven-dried for 24 hours at a constant temperature of 105 ± 5 °C.…”