Utilization of Electroplating Sludge as Subgrade Backfill Materials: Mechanical and Environmental Risk Evaluation

Table 3

Unconfined compression strength of lime-coal fly ash stabilized materials (MPa).

Structure layer	Highway grade	Special heavy traffic	Heavy traffic	Light traffic
Base	Motorways and first-grade highway	≥1.1	≥1.0	≥0.9
	Second-grade and under second-grade highway	≥0.9	≥0.8	≥0.7
Sub-base	Motorways and first-grade highway	≥0.8	≥0.7	≥0.6
	Second-grade and under second-grade highway	≥0.7	≥0.6	≥0.5