Optimize The Lime Content To Treat Recycled Mushroom Substrates In Concrete

Disposing spent mushroom substrate has been a major problem faced by farmers especially in areas such as Pennsylvania where its output far exceeds existing demand. And the high soluble salts concentration of these wastes has restricted their immediate application in the agricultural arena. Widespread and year-round field inventories of spent mushroom substrate created a great environmental nuisance because of various pollutants contained in the waste. In this research, we are trying to come up with a solution to recycle this farm waste as a part of concrete materials. They may be added as a sand substitute into those concrete used in constructing sidewalks, ground support for signboards or posts, sound walls, and other nonstructural facilities. It was found that these wastes should be treated with quicklime or cement before being mixed into concrete as a partial substitute for sand. In order to make the recycling process both economical and applicable, the minimal amount of quicklime to be used in treating spent mushroom substrates and the maximal amount of sand that can be replaced was determined by considering both concrete strength and material costs. Based on some preliminary experimental results, a computational method is developed to evaluate the economical effect of recycling spent mushroom substrate into concrete.