PATCH ASPHALT 



.Asphalt 

 Riprap Potch 



-Filter 



SECTION 



Prototype Installation : 

 Unknown locations. 



Wave Tank Tests : 



Model tests conducted at Delft Hydraulics Laboratory, Delft, 

 The Netherlands. 



Patches of asphalt were poured on rock slope (above and below water) 

 to bind 5 to 10 rocks together. 



Stability coefficient K A increased two to three times over nonpatch 

 asphalt slope (d'Angremond, et al., 1970). 



Design Factors : 



Zero-damage wave height: Depends on rock size. 



Wave runup: 0.6 to 0.7 compared to smooth slope (estimated). 



Wave reflection: Medium (estimated). 



Remarks : 



Patch asphalt could be used to upgrade a damaged riprap slope or as 

 original construction. 



Three layers of riprap is recommended with asphalt patch affecting 

 only the top two layers. 



The bottom layer provides protection to the core if a patch is 

 washed out. 



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