An experimental study on the use of fly ash for making concrete lagging of SVP steel arches in underground coal mines in Quang Ninh area

In 2020, Vietnam has 25 thermal power plants in operation, emitting a total amount of fly ash and coal bottom ash of about 13 million tons/year. It makes increasing the costs of landfill space, and negatively affect the environment. The major goal of this study is to recommend an optimal amount of thermal power plant fly ash to be added to the concrete mix to create concrete lagging for the SVP steel arches of the underground coal mine in the Quang Ninh region. In order to lower the cost of drift support and improve the efficiency of environmental protection, fly ash is used in this study to make concrete lagging in place of cement to the extent of 30%. This study also demonstrates a recent development in the use of novel materials to construct rock/soil supports for underground mines in Vietnam. use of fly ash in concrete as a partial replacement for cement is more important today. The comparison of strength properties of concrete laggings by experimental study at the Laboratory of underground construction between two concrete lagging types at Hanoi University of Mining and Geology (HUMG) will show the benefits in terms of the strength of concrete lagging using fly ash. The paper also presents the results of an experimental study on using fly ash for making concrete lagging at the Laboratory. The comparison of the drift support using concrete laggings in SVP steel arches fly ash-made products and conventional underground mining support will aid in demonstrating the benefits of employing fly ash. From the study's findings, it can be inferred that fly ash can substitute cement in lower classes of construction concrete such as M200.