Addressing very large expansion cracks with GRCS
AIA Case History
Due to successful history of addressing many pavement maintenance challenges Douglas County, Nevada turned to long operating asphalt contractor, “Skip Brown” owner of Delta Construction. Skip joined his father at Delta Construction when just a teenager. He eventually took over the business that had 7 decades of operation. He was there continuously excluding the time to get a college degree. He learned every aspect of asphalt pavements and associated materials. His years of experience working in almost every climate and soil condition provided him a very broad knowledge base to attack varying site challenges as a consultant today.
Nevada has extreme weather swings and expansive soils which results in huge thermal cracking (4-5″] in both old and new asphalt pavements. In 2013 Mr. Brown suggested a unique remedy that has performed very well. His company had been placing GRCS [Geosynthetic Reinforced Chip Seals) for over 30 years. This resulted in crack mitigation success exceeding any other strategy to date. NOTE: Luis Rodriquez of Federal Highways researched the process in South America & titled the process GRCS. Delta Construction reviewed the challenge of the very large thermal cracks plaguing Douglas County so he designed a strategy to combat the problem. He felt that GRCS should be utilized with one additional twist.
Delta Construction took a section of Drayton Blvd starting at Dresslerville Road in Minden, Nevada and performed transverse saw cuts every 15′ in the existing pavement. The County then sealed these saw cuts with hot-pour polymer-modified asphalt sealant. Delta then placed a GRCS over the roadway. NOTE: It is critical the cracks are filled all the way to the surface prior to the GRCS system. Otherwise the binder placed for the interlayer will be lost in the depression and not available to saturate the interlayer. Once the system is complete, there is no future need to place crack fill in any very minor voids at the saw cuts.
A visit to the site in 2019 saw minimal voids at the saw cuts attributed to underfilled saw cuts. The County did crack seal those indentations even though waterproofing was intact. At the end of the saw cut section and the beginning of GRC only section random 4-5″ cracks are now common. The fabric interlayer is still mostly intact in those large cracks providing waterproofing; however, the huge cracks are very unsightly and result in very poor rideability.
For additional information please contact AIA at 800.650.2342
#1 This shows the very minor indentation of the saw cut after 6 years. The indentation is magnified by the saw cut not being filled all the way to the surface prior to the GRCS placement. Crack fill on top of the indentation is not required as the waterproofing membrane is intact.
#2 The GRCS section without saw cuts is at the bottom of the photo and a very large random crack has surfaced after 6 years. Looking up the road the saw cuts on 15′ spacings can be seen.
#3 This is an example of a major expansion crack surfacing after 6 years. The width approaches a shoe width and the depth is approximately 1″.