PURPOSE: To obtain a reinforced plastic alloy binder which is useful in pavement, blocks for pavement and interiors or exteriors for buildings by saturating the rockwool containing fibrous or granular aluminum entangled with a liquid synthetic resin and adjusting its viscosity.

CONSTITUTION: The reinforced plastic alloy binder is obtained as follows: ores different in their hardness are mixed, molten at an elevated temperature into rockwool and the rockwool is mixed with fibrous or granular aluminum so that they entangle with each other, then, the rockwool is saturated with a vinyl ester resin or polyester resin, epoxy resin, urethane resin, fluorine resin, urea resin of about 1,000cps viscosity, and the viscosity is adjusted to 1,800 to 150,000cps. The binder is used in pavement, pavement blocks, interior or exterior walls for buildings, bank protection or sand guard.