Backfilling: Backfilling material must be approved by ASTM and AASTHO cods. While used back filling material is not only consider code must be provided adequate thickness or layers. Compaction must be achieved 95-100 percentage (MDD).

Subgrade: Subgrade is the original foundation of the roads, used material confirm by CBR & Plate Load Test. Detrimental subgrade can induce settlement in future.

Subbase: Its is also a crucial part of the road. Load transfer and distribute by this part. Drainage provides by this part. Graduation, Plasticity index, and field compaction test confirm the above mention criteria.

Basecourse: A structural layer provided before asphalts. Field density and grading and loss angels abrasion test confirm material adequacy.

Many Researchers and field civil engineer blame only inadequate bitumen layer induce failure of road they not properly address it base material or substructure part.

Categories

Laboratory Testing

Keywords

Soil