“Covering Effects” under Diurnal Temperature Variations in Arid and Semiarid Areas

Table 1

Physical properties of the test soils.

Soil type	Specific gravity	Compaction characteristic		Atterberg limits
		Optimum moisture content (%)	Maximum dry density (g/cm^3)	Liquid limit (%)	Plastic limit (%)	Plasticity index
Loess	2.66	14.1	1.8	30.5	17.69	12.81
Sand	2.67	9	1.6	—	—	—