Key-parameters for the strength control of soil-cement mixtures
DOI:
https://doi.org/10.14195/2184-8394_109_2Keywords:
Soil-cement mixtures, Water/cement ratio, Void/cement ratio, Uniaxial compression testAbstract
Often, the use of traditional techniques in geotechnical engineering faces obstacles of econo mi cal and environmental nature. The soil-cement technique becomes attractive when the improvement of the local soil is a project alternative. The treatment of soils with cement finds application, for instance, in the cons truction of pavement and railroad base layers, in slope protection of earth dams and as a support layer for shallow foundations. However, there is no dosage methodologies based on a rational criteria, as it exists in the case of the concrete technology, where the water/cement ratio plays a fundamental role in the assessment of the target strength. In that sense, this study aims to quantify the influence of the amount of cement, the porosity and the moisture content on the strength of a sandy soil artificially cemented, as well as to evaluate the use of a water/cement ratio and a voids/cement ratio to assess its unconfined compression strength. A number of unconfined compression tests and measures of matric suction were carried out. The results show that the un con fined compression strength increased linearly with the increase of the amount of cement and exponentially with the reduction in the porosity of the compacted mixture. Besides, the change in moisture content has re mar kably affected the unconfined compression strength of mixtures compacted in a same dry density. It was verified that, for the soil-cement in the unsaturated state (state usually met by compacted fills), the water/ce ment ratio is not a good parameter for assessment of unconfined compression strength. In the other hand, the voids/cement ratio, defined by the reason between the porosity of the compacted mixture and the volumetric cement content, adjusted by an exponent, demonstrated to be the most appropriate parameter in the assessment of unconfined compression strenght of the studied soil-cement.
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