For optimal length of fiber additive, both types of fiber reinforced
cement soft clay reached their maximum strength
when mixed with fibers of the longest lengths, with an accelerating
growth rate. Therefore, it can be estimated that the optimal fiber
lengths are probably higher than what the authors have tested.
When the improved clay were mixed with the same content of fibers
or fiber bundles, the inclusion of longer length fibers means
that fewer single fibers will be mixed. Less single fibers will result
in an even distribution of fibers. Longer fibers are hard to be pulled
out and can bond more soil particles together. Therefore, considering
the magnitude of the ground as well as what the authors have
analyzed above, the optimal lengths of the two fiber additives
should be much longer in practice.