abstract backdrop backgrounds cement concrete construction masonry patterns rough surface textures wall wallpaper appearance base black builders’-mesh building concrete-work concreting edged edging form forming formwork foundation foundational groundwork level leveled leveling levelled levelling mesh plastic pour poured pouring preparation prepared preparing sheeting smooth smoothing solid solidify spread spreading strength strong sunlight surfaces tools work working background city decay grunge San Francisco sidewalk texture urban walk walkway alphabet-A arrow direction Dirt dirty discoloration discolored discolouration discoloured gray grey grooved grooves non-slip path pathway patterned paving raised Soil soiled surfaced textured uneven blue-metal chips embedded granite gravel pebbles rocks shapes size Sizes slab stones angled angles basic color colour curved curves curving external footpath ground hard-surface hard-surfacing lined lines mottled mottling outdoors outside pavement perspectives streaked streaks variations architectural architecture cracked cracks edge edges exterior going-up rugged safety secure shape shaped stairs steep steps surfacing thick UP