Laterite is prone to aggregate and difficult to disperse. When treated with lime

it actually adheres to the surface of aggregates in fact

resulting in inhomogeneous distribution inside and outside. In this study

two groups of laterite were selected with different aggregate sizes ( 5.0 mm and 0.5 mm). A series of mechanical and hydraulic properties tests

such as shrinkage test

compression test and direct shear test

were conducted

and the effects of hardening and intergranular cementation on the surface of treated laterite aggregates were evaluated. The results showed that aggregate size

initial water content

and treated method significantly affected the treating effect. Compared with the treatment with lime alone

the metakaolin-lime cooperation method was better

with reduced compressibility

increased cohesion and reduced shrinkage. However

the treatment effect was influenced by the aggregate sizes of laterite

and the improvement of mechanical and hydraulic properties of laterite declined with the increasement of aggregate size. Based on this

it can be inferred that after treatment

“hard shell” was formed on the surface of laterite aggregates

which improved the compressive resistance and surface roughness of the aggregate. Cementations were formed between aggregates

inhibiting the shrinkage behavior and improving the cohesion

but after aggregate size increased

the influence scope of metakaolin-lime was limited to the surface of aggregates

and the aggregate size effect counterbalanced the treatment effect of metakaolin-lime.