Economical development has triggered the enforcement of a large scale of national land development, road construction & housing construction projects causing a rapid increase in aggregate amount used. And now national land environment is being destroyed by the rubble & rubble sand collection as the river sand, river gravels and even sea sand are being exhausted. Like this, the amount of aggregates demanded is increasing every day causing extreme shortage of supply of them, and so the use of recycled aggregates from grinded construction waste, that is, waste concrete seems to be indispensable to balance the demand and supply of the aggregates. Therefore, a use amount of recycled aggregates would be enlarged gradually, but due to the lack of understanding of recycled aggregates and lack of multiple studies on recycled aggregates-used concrete, most of them are used for non structural use such as for embankment or as the molding, subgrade materials for road construction. So, a production plan for recycled aggregates needs to be made first under the consideration of their weak properties that is their weakness in intensity, and high water absorbtion rate affected by cement pate on the aggregate surface need to be complemented in the way of elevating their quality. Accordingly, this researcher will prepare in this study a base on which recycled aggregates would be useful by processing the breaks and cracks on their surface with potassium silicate for the purpose of lifting their quality which are inferior to that of natural aggregates.