Impact of Panel Dimensions on Material and Construction Costs

There is no information available from highway agencies that has provided insight on the correlation of construction costs to the panel size of thin concrete overlays. In general, as panel dimensions decrease, the amount of sawing (in linear feet) required will increase.

Table 1 provides a simple calculation of the amount of sawing required for 60 linear ft (18.3 m) of a two-lane pavement of width 24 ft (7.3 m). As shown in this table, a 6 ft by 6 ft panel (1.8 m by 1.8 m) size requires two and a half times the amount of saw cuts (in linear feet) as a 12 ft by 12 ft (3.7 m by 3.7-m) panel; likewise, a smaller 4 ft by 4 ft (1.2 m by 1.2 m) panel requires nearly four times as much sawing as a 12 ft by 12 ft (3.7 m by 3.7 m) panel.

While the cost of additional sawing does not approach the cost savings associated with using less thickness for the overlay, the “time cost” of sawing and the effects of the need for additional sawing on the project should be considered. As noted in the construction and case studies section, saw cutting crews should account for the faster speed of thin overlay placement relative to its thicker counterpart, and should also recognize the increased joint sawing quantities associated with thin concrete overlays. Moreover, thin concrete overlays have a higher ratio of surface area to volume, making them more susceptible to random cracking if the joints are not sawed in a timely fashion. Thus, sufficient sawing crews and equipment should be mobilized in order to match the pace of paving and to accommodate the required sawcutting quantities.