Marc Choquette

Bio: Marc Choquette is an academic researcher from Laval University. The author has contributed to research in topics: Lime & Atterberg limits. The author has an hindex of 7, co-authored 7 publications receiving 597 citations.

Laboratory investigations on the lime stabilization of sensitive clays: shear strength development

Abstract: A laboratory investigation on the quicklime stabilization of sensitive clays has shown that, even at a water content above the liquid limit, significant strength increase can be obtained if enough ...

Behavior of common rock-forming minerals in a strongly basic NaOH solution

Abstract: The pH of the pore solution existing within concretes or lime-treated soils normally exceeds 12. When exposed to a solution witl a pH over 10, several rock-forming and soilforming minerals are unstable, and dissolve with or without precipitation, depending on the nature and concentration of species in solution. In concrete, made with a typical cement containing 0.7a/o to l9o alkalis, after a few days, the composition of the liquid phase is dominated by sodium, potassium and hydroxide ions. In this study, the behavior of several common minerals in a pure sodium hydroxide solution was evaluated by the means of two experiments. First, mineral fragments were immersed in a lN NaOH solution at 23oC for 265 days, then at 80oC for 7 days. The specimens were regularly analyzed with a SEM-EDX system. Secondly, the release of silica by silicate minerals in a lN NaOH solution was measured by means of the Chemical Method ASTM C 289 test (80'C, 24 hours). Of all rhe silicate minerals tested, the microcryslalline variety of silica, chert, was the most unstable phase. Significant quantities of silica also were released by quartz and feldspars. Iron and magnesium silicates were found to be the mosr stable phases in the NaOH solution. Among the other minerals investigated, dolomite, siderite and gypsum are classified as highly reactive in the alkaline solution.

Physicochemical and engineering behavior of cement treated clays

Abstract: This paper examines the relationship between the microstructure and engineering properties of cement-treated marine clay. The microstructure was investigated using x-ray diffraction, scanning electron microscopy, pH measurement, mercury intrusion porosimetry, and laser diffractometric measurement of the particle size distribution. The engineering properties that were measured include the water content, void ratio, Atterberg limit, permeability, and unconfined compressive strength. The results indicate that the multitude of changes in the properties and behavior of cement-treated marine clay can be explained by interaction of four underlying microstructural mechanisms. These mechanisms are the production of hydrated lime by the hydration reaction which causes flocculation of the illite clay particles, preferential attack of the calcium ions on kaolinite rather than on illite in the pozzolanic reaction, surface deposition and shallow infilling by cementitious products on clay clusters, as well as the presence of water trapped within the clay clusters.