Sand, gravel, crushed stone, asphalt, bitumen, cement, gypsum for use in construction, road construction, repair and covering work; traffic signs not of metal, non-luminous and non-mechanical, for roads; monuments and statuettes of stone, concrete and marble; non-metal building materials, namely, natural and synthetic asphalt and bituminous surface coatings in the form of panels and sheets for use on doors, roofs, walls and pavements; heat adhesive synthetic surface coating of bitumen, being ...