Herbicides offer the engineer a means for controlling vegetation involving asphalt surfaces. The plants may arise from seeds or plant parts in the base material, by encroachment of plants from outside the pavement, or from seeds that become lodged in cracks or seams in the pavement. Bermudagrass and many associated plants can be controlled with either presurface or postsurface application of herbicides. Presurface treatment just before the prime coat effectively prevents the penetration of the new surface by plants growing from the base material. Postsurface treatments are applied on a program basis beginning with the start of plant growth in the spring. Subsequent treatments are applied when the plants again become green, usually 30 days following the initial treatment. A tca application at 200 lb/acre is used for each post-surface treatment. Research is still seeking effective postsurface treatment for a mixture of annual and perennial broadleaf and grassy weeds in northwestern texas. Materials recommended for open-soil treatment in agriculture are not as effective when applied to the same materials growing in asphalt surfaces.
Samenvatting