Two new forms of pressure-membrane apparatus are described. One has been developed for routine use, while the other has been used for pressure-membrane tests at very high pressures (up to 1,500 atmospheres, or p F 6.2).For soil in both the wetting and drying condition it is shown that the relation between suction and moisture content determined by pressure-membrane tests agrees with that obtained using the suction plate, the centrifuge, the vacuum desiccator, and the sorption balance. The rate of attainment of moisture equilibrium in the pressure membrane is also examined experimentally, for a verywide range of air pressures.
Synopsis Laboratory studies have shown that a red clay soil from Nyeri, Kenya, (which occurred immediately beneath the top soil and was seasonally air dried in situ) possessed unusual properties, including an excessively high moisture sorption, increase in index values with prolonged mixing and abnormally low optimum dry density for B.S. compaction. The explanation of these properties is shown in this Paper to lie in the mineralogy and structure of the soil, and by use of colour studies it is shown that the meta-halloysite and quartz in the soil are coated overall and cemented with haematite. In the Appendix, brief consideration is given to a mechanism of formation of the red clay soil from basalt, and it is shown that this mechanism is consistent with the known geological estimates of the age of the soil. Des études de laboratoire ont montré qu'un sol d'argile rouge de Nyeri, Kenya (qui se trouvait immédiatement au-dessous du sol supérieur et était séche à l'air et sur place pendant la saison), possédait des propriétés peu communes, comprenant une absorption excessivement élevée d'humidité, augmentation des valeurs d'index avec mélange prolongé et densité sèche optimum anormalement basse pour compacité B.S. L'explication de ces propriétés est indiquée dans cette communication comme due à la minéralogie et structure du sol, ct par l'emploi d'études de couleurs on a démontré que le métahalloysite et le quartz dans le sol sont complètement recouverts et cémentés avec de l'hématitc. Dans l'appendice, une considération brève est donnée à un mécanisme de formation du sol d'argile rouge provenant du basalte, et il est démontré que ce mécanisme est consistant avec les estimations géelogiques connues de l'âge du sol.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.