Criteria for Laboratory Studies on Fine Soils Treated with Lime

When selecting the appropriate materials for constructing road infrastructures, an important way for minimizing both the economical and environmental impact is to make use of lime for treating those natural soils that, involved in the earthwork for opening road fences, are not suitable, as they are in nature, to fulfill the specific requirements for being used as part of road construction, such as road embankments (including the capping layer) or the improved subgrade or, again, the sub-formation. From this point of view, the treatment of fine soils with lime (if needed, with lime and cement) can be considered as one of the main measures for preserving the natural environment since it fulfills the principles of minimizing the use of not-renewable natural resources and maximizing the reuse of those natural resources involved, in any case, in the construction of a road infrastructure. Due to the importance of the technique examined here and to its topicality, as said before the aim of the present work is to provide a specific methodology and an overall view of the performance criteria for the experimental studies that, in the design phase of the road construction, have to be carried out in laboratory in order to evaluate the suitability of soils to lime treatment, the mix design of the lime treated mixture (type of lime to be used and its content), as well as the foreseeable execution conditions in the field that have to be considered, at a technical-economical level, in the contract specification and in the assessment of the cost of the project. After that, some peculiar aspects connected with the executive operation in the construction field will be examined, attention being paid to the construction machinery, to the specific equipment and to the procedures to be followed in order to perfect the treatment process and to control the quality of the final product.