the incidence of cracks not associated with externally applied loads is a feature of soil-cement roadbases, and the consequent problem of reflection cracking through the superimposed surfacing has caused concern over the years. the cracks result from restrained thermal and shrinkage movements but, when the stabilized soil is fine-grained, it is believed that the cracking is mainly attributable to shrinkage. the paper describes a study of the autogenous shrinkage of such a material aimed at improving the understanding of its susceptibility to cracking. in the investigation, specimens were cured under ideal conditions, but, because conditions in the field are often far from ideal, the influence of drying on shrinkage was also studied. the principal finding of the investigation is that the measured value of shrinkage is greatly affected by the test conditions imposed. in particular, major differences were observed in specimens compacted by different methods and, furthermore, the mode of compaction had a striking influence on the way in which the cement content of mixes influenced shrinkage. a tentative explanation for the results obtained is presented in terms of the pore pressure in the specimens, the hydration of the cement and the particle orientation. it is clear, however, that further work is necessary before the general validity of the results can be determined.(a)

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