Influence of bond geometry on the hydro-mechanical behaviour of sands treated with cement
DOI:
https://doi.org/10.14195/2184-8394_153_1Keywords:
bond, soil-cement, sand, microstructureAbstract
Artificially cemented soils result from mixing soils with hydraulic binders, in which particles are joined together through physical bonds (minerals from the hydration of the binder). The geometry of the connections is controlled by the amount of water used in the preparation which, in turn, depends on workability requirements and the addition or not of adjuvants. In compaction the amount of water is low and the bonds tend to concentrate on the contacts between the particles, where water concentrates in unsaturated soils. In the injection the quantity of water is high (as well as the dosage), and the connections are dispersed. The form how the geometry of the connections due to the water used at preparation affects the hydro-mechanical behaviour of sandy soils treated with Portland cement is discussed. The results of tests carried out on samples of sand treated with different dosages of cement and water/cement ratios, which allowed the characterization of its mechanical and hydraulic behaviour, as well as non-destructive tests to characterize these connections, are used as example. Double porosity is observed when the connections are concentrated, which affects mainly the hydraulic behaviour. The mechanical parameters are sensitive to cement dosage, however the amount of water also impacts this behaviour because it affects the hardened cement paste.
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