EAGLE CORR PE™ * - JM Eagle

Selection of proper compaction equipment depends on the desired densityand type of material being compacted. Crushed stone, sands and gravelsare more easily compacted when vibratory equipment is used to transfercompaction energy. Highly plastic materials such as Class III and IV materialsrequire moisture control plus and a higher amount of compaction energyinduced by kneading and impact forces. Jumping jacks and walk-behindvibratory rollers are suitable for most classes of backfill materials, providedmoisture content is controlled.Crushed stone is usually not compacted. However, care must be taken toensure the material is properly placed in the pipe haunch zone. Typically,using a shovel to knife the material in the haunch area provides suitablebackfill support. Additionally, studies have shown that wetting the crushedstone reduces the friction between the fractured faces and improves in placestrength of the material.Figure 314.10.1 Hand Compaction in Haunch AreaIt is the discretion of the contractor (or design engineer) to determine the bestmethod to achieve required compaction in the haunch area.Tamping bars have been successfully used to compact the backfill in thepipe haunch zone.4.10.2 Mechanical Tampers48 EAGLE CORR PE INSTALLATION GUIDE