Construction
Surface Texturing
Timing
Concrete pavement surface texturing operations should be performed at just the right time in order not to disturb the curing or setting of the concrete. Texturing should be performed just after the water sheen has disappeared but before the concrete becomes non-plastic. The water sheen can be seen in Figure 3.1.
Figure 3.1 - Water Sheen on Concrete Surface.
Texturing Methods
Texturing of the concrete pavement surface can be effected by several different methods, depending on the facility type and design speed of the facility, or expected operating speeds of vehicles on the facility. For example, at highway speeds, vehicles require the additional tire-pavement interaction provided by increased texture in the pavement surface.
If needed in irregular areas, texturing can be completed by hand with a small burlap or turf drag or portable tining comb.
Low-Speed Facility
For lower-speed facilities such as city streets, residential areas, or other urban or municipal applications, less texturization is required. One potential exception to this may be whitetopping at intersections where transverse texture may be desirable to improve stopping skid resistance. Texture applications such as burlap drag (Figure 3.2), turf drag, or a coarse broom (Figure 3.3) are sufficient.
With a burlap or turf drag, the material is often dragged from the paving train across the entire paving width. With a coarse broom, as shown in Figure 3.3, the broom is often pulled transversely one broom width at a time, along the entire length of the freshly placed pavement.
Figure 3.2 - Application of Texture with Burlap Drag.
Figure 3.3 - Application of Texture with Coarse Broom.
High-Speed Facility
For high-speed facilities, such as highways, freeways, and higher-speed urban streets, increased texturization is most often required. Generally, this type of texture is performed by a tining comb (see Figure 3.4).
It is important, when using a tining comb, to make shallow (1/4-inch deep) striations in the transverse direction. The tining comb should not overlap its previous passes. Tining should also be avoided at the pavement edge, joint sawing locations, and other places where a pavement edge is encountered. Avoiding pavement edges reduces the potential for damage to the pavement from the tining operation.
Figure 3.4 - Tining Comb Texturization on Freshly-Placed Concrete.
