Crack sealing was completed on all of the asphalt surfaces during the project. Due to dust regulations, the city of Henderson will not allow conventional methods of crack cleaning. Cracks were cleaned using a Crack-VAC, which uses compressed air blown through three nozzles. As the air is blowing the cracks clean, the blown dirty air is vacuumed into a holding tank on the unit then disposed. The Crack-Vac is PM 10-approved for air quality.
The crack sealing materials was applied with a wand. It was completed 20 days prior to the micro surfacing and cape seal applications by a six-person crew of Superior Asphalt, Salt Lake City, UT.
“The crack seal was a special hot rubberized crack sealant material designed for the hot Las Vegas climate,” says Reimschiissel.
Henderson’s pavement maintenance project included micro surfacing on residential, collector and arterial locations.
“The micro surfacing was completed on asphalt surfaces in good condition as a preventive application and asphalt surfaces in poor condition as a method of holding the pavement in a serviceable condition until funds are available for new asphalt or reconstruction,” explains Reimschiissel.
Due to the locations of the major roads with businesses, casinos and shopping centers, the micro surfaced roads were done at night.
The micro surfacing was a Type 2 gradation application with 3% latex. Mix designs were completed for both day and night applications. A crew of 14 people using three micro surfacing machines was used to place the material.
During the micro surfacing process, day time temperatures reached 85 to 90 degrees while nighttime temperatures were approximately 65 to 75 degrees.
The cape seal consisted of a 3/8 chip seal using a PASS rejuvenation emulsion supplied by Western Emulsions. The chip seal was then covered by a Type 2 micro surfacing material.
“The Cape Seal application was placed on cracked asphalt surfaces to provide an application of rejuvenation and as a mass crack filler with a new micro surfacing type surface on the chip sealed surface,” says Reimschiissel. “The PASS chip seal emulsion is a rejuvenation emulsion to aid in enhancing the life span of the older pavements.”
The Cape seal was completed by Cactus Asphalt, Phoenix, AZ, with a crew of 16 people.
The cape seal locations were in industrial areas and on major roadways by casinos, shopping centers, a college and business office complexes. Due to the location of the work, the cape seal was placed at night between 9 p.m. and 6 a.m.
The chip seal was placed and allowed to set, then the micro surfacing was placed. Temporary floppy tabs and painted crosswalks were placed on the micro surfacing surface prior to opening the area to traffic. All of these work activities were to be completed and the road opened by 6 a.m.
“The challenge was to have the chip placed in time to set then the sweeping completed to allow time for the micro surfacing to be applied,” says Reimschiissel.
Sweeping was completed by both vacuum and broom sweepers. The micro surfacing was placed over the cleaned chip surface, completed, set, pavement markings installed and ready for traffic.
Coordination brings it all together
There were over 35 people involved in all of the crews for the various work activities.
“Coordination between the traffic control crews, chip seal crew, sweepers, micro surfacing crew and the pavement marking crew was a challenge that required preparation and cooperation,” says Reimschiissel.
The project was completed safely, on time, under budget, and with a happy customer, he notes. “The City of Henderson is very happy with the project and has added another location for a micro surfacing application in the spring of 2012.”