Heating and Scarifying Treatment
Description
405.01This work consists of recycling the top portion of the existing asphalt pavement as
shown in the Contract, by cleaning, heating, scarifying, redistributing, re-leveling, compacting, and rejuvenating the existing asphaltic material.
Materials
405.02Asphalt rejuvenating agent shall meet the requirements of subsection 702.02(f)
Construction Requirements
405.03Weather limitations shall be as provided in subsection 401.07. Before commencing
heating and scarifying operations, the pavement shall be cleaned of all loose material. Power brooms shall be supplemented by hand brooming and use of other tools as required to bring the surface to a clean, suitable condition free of deleterious material.
Equipment used to heat and scarify the asphalt surface shall meet the following requirements:
radiant heat.
surface to the extent that it will be remixed by the scarifiers to a depth not less than specified. The heating operation shall extend at least 4 inches beyond the width of scarifying on both sides. When a pass is made adjacent to a previously placed mat, the longitudinal seam shall extend at least 2 inches into the previously placed mat. The temperature of the scarified material shall be between 200 and 300 ºF when measured immediately behind the scarifier. The scarified material shall be distributed and leveled by a paving machine. The paving machine shall be capable of screeding the full width of the scarified material to produce a uniform cross section as shown in the Contract.
While the scarified material is still hot and before it is placed by the paving machine, an application of asphalt rejuvenating agent shall be applied as specified.
The asphalt surface shall be compacted immediately after it has been distributed and leveled, and while it is still workable. Two rollers shall be used to compact the scarified material. A steel wheel roller shall be used first to provide breakdown rolling, followed by a pneumatic tire roller with a minimum weight of 12 tons, to complete compaction to 92 to 96 percent of maximum theoretical density. When the mixture surface temperature falls below 165 ºF, no further compaction effort shall be done unless approved. A minimum of 24 hours shall elapse before an asphalt pavement overlay is applied to the scarified pavement.
405.04
The weight per cubic foot of the existing asphalt surface shall be determined per AASHTO T 166. Scarification depth will be acceptable when the moving average of a minimum of three consecutive random tests per hour indicates that the required amount per square foot, based on the weight per cubic foot of the existing asphalt surface, has been scarified. Testing shall be performed by the Contractor in lots of three per hour, or as often as necessary to maintain process control.
The longitudinal surface smoothness of the roadway before and after heating and scarifying shall be tested per subsection 105.07(f).
Method of Measurement
405.04Heating and scarifying treatment will be measured by the square yard of work
completed and accepted.
Basis of Payment
405.05The accepted quantities of heating and scarifying treatment will be paid at the
contract unit price per square yard for heating and scarifying treatment, and shall include cleaning, heating, scarifying, redistributing, re-leveling, and compacting the existing asphalt surfacing.
Payment will be made under:
Pay Item Pay Unit Heating and Scarifying Treatment Square Yard
Asphalt rejuvenating agent will be measured and paid for per Section 411.
Get an email when 405 changes
Colorado revises spec sections through supplementals and new editions. We check this one every week and email you the day it changes. Free, no account.