Effect of Gravel Size, Type, and Mold Size on the Carrying Capacity of Calcareous Fines-Gravel Mixes

Abstract

Calcareous soils are used as graded base course materials in the Eastern Province of Saudi Arabia. The specimens tested in the laboratory are different from those in the field because of the removal of the oversize particles. The effects of maximum aggregate size on the load carrying capacity of calcareous fines (marl)-gravel mixture were studied. A large-size mold that can accommodate particles up to 50.8 mm was used to study the effect of oversize particles. Limestone aggregates (LSA) and steel slag aggregates (SSA) were used. The results indicate that the California bearing ratio (CBR) and the Clegg impact value (CIV) increase with the increase in the maximum aggregate size. The increase in the CBR values can reach 19% when the maximum aggregate size was increased from 19.05 to 50.8 mm. The CBR values for the calcareous fines-SSA mixtures were greater than those for the calcareous fines-LSA mixtures by up to 24%. The conventional CBR mold overestimates the CBR values by up to 43%. The results also clearly indicate the strong correlation between the CBR and the CIV results.