Abstract:
Road construction in Northeastern Thailand encounters the
problem or material dericiency or rock products being used ror base
course. The most available local materials are lateritic soil,and
terrace gravel which easily round out in this region. Cement
stabilization or lateritic soil was recommended to replace crushed
rock base in rlexible pavement structure. The project is studying
about durability or soil-cement which was a part or a long-term
research project ror the sake or studying about the reasibility or
employing soil-cement in place or crushed rock ror base course.
In side ofThailand. this project,lateritic soils were collected from the right
Phangkone-Buengkan Road at Km.50+600 in the Northeastern Thailand.
The average slake-durability index was about 95.43".
Durability obtained rrom conducting a wet-dry test had great losses or
weight by brushing in the rirst 7 days curing, because the hydrated
reaction was incompleted. After that the loss or weight was very
slightly occurred. The relationship between cement content and loss or
weight or between age of curing and loss of weight is an inverse
proportion.
The straight line showing relationship between UCS and loss of
weight with 3X and 4X of cement content indicated similar slopes,while
the loss of weight with 5%, 6%. and 7% of cement content the straight
line had steeper slopes.
The slopes of the straight line for 1, 3, and 7 days curing were
nearly equal, but those for 14 and 28 days curing the slopes tended to
increase. This tends to show the effect of curing on durability of
soil-cement. The influence of age of curin,g had more effect on
durability of soil-cement before 7 days curing,after there was some
effect on durability of soil-cement.
The relationship between CBR and loss of weight had the same
trend as that between UCS and loss of weight. The value of UCS and
CBR trend to increase in the same rate depending on cement content and
ages of curing.
When comparing the test result with the PCA criteria, a suitable
cement content used with this soil-group (A-2-7) should not be below
6X by weight of dry soils, which gives good results for both strength
and durability of soil-cement.