Análises macro da deformabilidade de solo-cal no domínio das pequenas deformações

Lusical, Université Libré de Bruxelles , Lhoist R&

Evolution mécanique et physico‐chimique à long terme d’un sol limoneux traité à la chaux.

peer reviewe

Geomechanical behaviour of stabilized soils with lime; the main contributions of COGESTAC

Os efeitos imediatos do tratamento com cal são bem conhecidos, e largamente aplicados. Porém, os efeitos de longo prazo (estabilização) têm sido menos estudados até agora. O projecto COGESTAC, com duração de 4 anos, abordou a vários níveis o tema da estabilização dos solos com cal, à escala micro e à escala macro. O efeito de agentes exteriores foi também considerado neste estudo. Esta investigação destaca-se pela diversidade e pela campanha ambiciosa de ensaios envolvendo provetes de solo tratado acondicionados durante vários anos. Os resultados apresentados neste artigo representam um interesse directo para o dimensionamento das infra-estruturas rodo-ferroviárias, bem como para uma análise do ciclo de vida deste tipo de estruturas.The immediate effects of the lime treatment are already well known, and widely used. However, the long-term effects (stabilization) have been less studied up to now. The four years project COGESTAC investigates at several levels the theme of soil stabilization with lime, to the micro and to the macro scales. The effects of exterior agents were also studied. This investigation stands out for the diversity and for the ambitious test programme including treated soil samples cured up to several years before testing. The results presented in this paper represent a straight interest for the design of road and railway infrastructures, as well as for an analysis of the life cycle of these structures.Departamento de Engenharia Civil da Universidade do Minho (DEC-UM

Contribution of loamy soil treatment to improve embankments performance

This paper shows for a loamy soil the benefits of lime treatment on the evolution of the geomechanical properties governing the slope stability and the resistance against erosion of embankments. The main results indicate that the effective internal friction angle (φ) is quite unchanged through time, while the effective cohesion (c’) strongly increases. Furthermore, erosion tests using the LCPC erodimeter on slopes between 0 and 30 degrees, and for a curing time up to 112 days, have shown that the treated soil becomes insensitive to erosion after a few days. These results clearly establishe the benefits of lime treatment in safety and serviceability of embankments for highways and high speed trains and, consequently, have an important impact on the reduction of their life cycle costs.(undefined

Contribution of loamy soil treatment to rise embankment performance

info:eu-repo/semantics/publishedGeotechnical Special Publicatio

Comportamento geomecânico de solos estabilizados com cal. Principais contribuições do projecto COGESTAC

info:eu-repo/semantics/nonPublishe

Mechanical behavior of natural and recycled granular materials for roads

This paper presents a study on resilient and permanent strains measured with the precision cyclic load triaxial test on a limestone aggregate (reference material) commonly used in subbase or capping layers in Belgium and on two recycled materials (steel slag and crushed concrete aggregate) also used in subbase or capping layers. The influence of stress level, water content, density, and compaction method (vibrating hammer or vibrocompaction) was analyzed. Tests with one cyclic stress level on one specimen (single stage loading) and tests with several cyclic stress levels on the same specimen (multi-stage loading) were performed, in order to evaluate the prediction capability of the multi-stage loading test. The latter test procedure is quicker and more practical. Although the permanent strains obtained by the two test procedures were different, the multi-stage loading method did indicate the trend of the long-term behavior of the material. The test results showed that in comparison with the reference material, the recycled materials, particularly the steel slag, exhibited good mechanical behavior (high stiffness, high strength, and good resistance to permanent strains) under-well controlled conditions of water content

Influence of curing time, percolation and temperature on the compressive strength of a loam treated with lime

Paris communication C022info:eu-repo/semantics/publishe

Strength and micro coupling of a lime treated silty soil

accepté pour publication dans les proceedings de GeoHunan International Conference 2011, et dans American Society of Civil Engineers (ASCE) Geotechnical Special Papers 2011info:eu-repo/semantics/nonPublishe

Strength and micro observations on a lime treated silty soil

A large laboratory research project founded, by the European Community and involving Academies and Industry has been carried out to fill the gap between the empirical design rules of soil treatment by lime and the mechanistic design approach used for transportation infrastructures. This required a multidisciplinary approach both at macro/micro-scales, using common geomechanical test methods, microscope observations and micro scale tests. These tests were performed on samples of a silty soil that had been treated with respectively 1.5, 3 and 4.5% calcic quicklime. The curing conditions were chosen as main parameters for the testing program, viz. time (up to 730 days) and temperature (20, 36 and 50 °C). Due to a lack of space, only results with samples cured at 20°C are presented in this paper. All evolutions of the mechanical parameters were coupled to the micro-scale test results. The aim of this analysis was to gain a better insight in the relation between strength macro-scale parameters and micro-scale reactions such as the development of CSH and CAH during pozzolanic reactions. © 2011 ASCE.SCOPUS: cp.pinfo:eu-repo/semantics/publishe