a strong hard building material composed of sand and gravel and cement and water

cement - concrete pavement is sometimes referred to as cement
reinforced concrete / ferroconcrete - concrete with metal and/or mesh added to provide extra support against stresses

    building material     paving material

form into a solid mass; coalesce

    solidify

cover with cement; "concrete the walls"

    cover

capable of being perceived by the senses; not abstract or imaginary; "concrete objects such as trees"

    tangible     practical     real     existent

    factual     objective     real     tangible

    abstract

formed by the coalescence of particles

    solid