Study On The Workability And Intensity Of Using Waste Concrete To Make Recycled Mortar

Recycled fine aggregate is a green building materials, it has the followingadvantages, waste recycling, environmental protection, energy saving and emissionreduction, stable mechanical performance. Compared with traditional natural fineaggregate, the application of recycled fine aggregate reduces emissions ofconstruction waste and extraction of natural river sand, so our surroundings get theprotection and improvement; Besides that, it solves the problems of constructionwaste processing and transportation construction, it crushes the construction waste,screening recycled fine aggregate can be directly applied to the project, whiledecreases the costs of acquisition and transportation of natural materials.In this article, recycled fine aggregate is made with6kinds of waste concretefrom different sources of construction through crushing and screening, and classifiedin accordance with Recycled fine aggregate for concrete and mortar. The recycled fineaggregate classified was designed to test factors according to different categories,different substitution rates and different mineral admixtures, then identify the impactof each single factor in the above conditions for regeneration mortar workability andmechanical properties; and conducted on its consolidated operating performance andmechanical properties through orthogonal experiment, screened recycled mortar mixproportion meeting Urumqi region’s conditions; Finally, observed the micromorphology of recycled mortar and analyzed the element content of different parts ofsamples respectively by scanning electron microscopy (SEM) and electronspectroscopy (EDXA), in order to verify the effects on regeneration mortarworkability and mechanical properties.The results showed that: The results showed that: There is one kind of recycledfine aggregate belongs to the class Ⅰafter crushing the waste concrete comes from sixdifferent sources, five kinds of recycled fine aggregate belong to Class Ⅱ, one kind of recycled fine aggregate belongs to the class Ⅲ.After studying on replacementpercentage found that class Ⅰ recycled fine aggregate replacement percentage shouldnot exceed50%, class Ⅱ, Ⅲ recycled fine aggregate should be less than30%.Selected optimum proportion is: Class Ⅰ recycled fine aggregate category→recycled fine aggregate replacement rate of30%→fly ash was10%; Ⅱ class fineaggregate category→recycled fine aggregate replacement rate of30%→20%lithium slag; class Ⅰ fine aggregate category→recycled fine aggregate replacementrate of30%→10%mineral powder. The surface of recycled mortar is rough,structure is loose and has more pores, and categories and quantities of element insecondary interfacial transition zone are complicated, all these may be one cause ofthe relatively poor performance of secondary mechanical interface transition zone.