Heavy Duty Block Filler is a pure acrylic, resin block filler for use on interior and exterior poured and precast concrete, concrete block and cinder block. Recommended for use over prepared masonry surfaces in dairies, bottling plants, mining industry, tunnels, chemical plants, paper mills, equipment foundations, jails, petroleum refineries, power plants, water and sewage, schools, treatment facilities, hospitals and industrial concrete ceilings and walls.