item 320 RUBBLIZE AND ROLL
320.04 Construction Details
320.05 Method of Measurement
320.06 Basis of Payment
320.02 Materials. Furnish filler aggregate conforming to Item 304.
If using a resonant frequency unit, ensure that it is capable of producing low amplitude, 2000-pound-force (8900 N) blows at a rate of not less than 44 blows per second.
If using a multiple head breaker unit, ensure that it has the capability of rubblizing the full 12-foot (3.6 m) lane width in a single pass. Ensure the breaking head consists of 12 to 16 hammers, each weighing 1000 to 1500 pounds (450 to 680 kg). Attach each hammer to a hydraulic lift cylinder that operates as an independent unit, develops 2000 to 12,000 foot-pounds (2700 to 16,000 J) of energy depending on lift height selected, cycles at a rate of 30 to 35 impacts per minute, and has a maximum lift height of 60 inches (1.5 m).
Use a vibratory steel wheel roller having a total weight of not less than 10 tons (9 metric tons).
320.04 Construction Details. Make a full depth saw cut or cut load transfer devices at existing joints on ramps or mainline where the rubblizing abuts concrete pavement or approach slabs that are to remain in place permanently or temporarily for maintenance of traffic.
Before the rubblizing operations begin, the Engineer will designate a test section. Rubblize the test section according to this specification. After rubblizing, excavate a test pit, where the Engineer designates, to check for proper particle size throughout the thickness of the concrete. Fill in the test pit using the excavated material and additional filler aggregate as necessary. Compact the test pit as part of the rolling operation. Excavate at least one test pit, at the location designated by the Engineer, for each production day or every 7040 square yards (5886 m2), whichever is greater.
Adjust the rubblizing procedure to maintain the proper particle sizes. Control the operating speed of the rubblizing equipment such that: 75% of the rubblized particles above the reinforcing steel are reduced to 3 inches (75 mm) in their largest dimension, 90% of the rubblized particles below the reinforcing steel do not exceed 9 inches (230 mm) in their largest dimension, and no particles exceed 12 inches (300 mm) in their largest dimension.
Before placing the initial asphalt concrete course, compact the rubblized pavement with two passes of the vibratory roller. Operate the roller in the vibratory mode and at a speed not to exceed 6 feet (1.8 m) per second.
Leave steel reinforcement in place in the rubblized pavement. However, cut off any exposed steel reinforcement below the surface and remove it from the site.
Fill depressions 1 inch (25 mm) or greater in depth compared to the immediate surrounding area resulting from the rubblizing, the compactive effort, or the steel reinforcement removal, with the filler aggregate. Strike off excess aggregate level with the surrounding area. Compact filled depressions with the same roller and compactive effort previously described.
Do not allow traffic on the rubblized pavement before the initial asphalt concrete base and intermediate courses are in place.
Do not allow more than 48 hours to elapse between rubblizing the pavement and placing the initial asphalt concrete course. However, in the event of rain, the Engineer may waive this time limitation to allow sufficient time for the rubblized pavement to dry to the Engineer’s satisfaction. If the Engineer waives the time limitation, cease rubblizing the pavement until the Engineer allows paving to resume.
320.05 Method of Measurement. The Department will measure Rubblize and Roll by the number of square yards (square meters). The Engineer will use the actual width of the existing concrete pavement and will measure the length along the centerline of each roadway or ramp.
The Department will measure the Filler Aggregate by the number of cubic yards (cubic meters) furnished, placed, and compacted.
Item Unit Description
Rubblize and Roll