| Description |
v, 62 leaves : illustrations, photographs ; 29 cm |
| Summary |
"A large number of the difficulties encountered in highway work are due to the variable nature of soils. In addition to its variable nature, soil is a difficult material to deal with because of the complexity of its physical and chemical properties. From prehistoric times the construction of a satisfactory foundation has been one of the greatest problems facing the engineer and builder. Even though the needs of scientific methods were necessary far earlier, the study of soils as a construction material was scientifically given attention to only during the last three decades. Soil science being so young there are quite a number of soil physico- chemical characteristics that we do not yet know and which we should try to determine in the near future to enable us to take better advantage of these phenomena in the engineering sense. This research which was suggested by Professor John B. Heagler, Jr. of the Civil Engineering Department of the Missouri School of Mines, has the goal of investigating the effect of carbon dioxide (CO₂) treatment on strength characteristics of calcium hydroxide Ca(OH)₂ treated soil containing some high swelling sodium montmorillonite clay. It was known that the addition of Ca(OH)₂ would flocculate the clay by utilizing a base exchange between sodium and calcium ions and thus increasing the load carrying capacity of the soil. The purpose of treatment of the Ca(OH)₂ soil mixture by CO₂ was to cause a reaction between the superstructural calcium ions in the diffused layer of the clay molecules and the CO₂ gas possibly forming CaCO₃ and thus increasing the load carrying capacity of the soil. Two similar sets of specimens were prepared. The first set of specimens was mixed with 2, 4 & 6 percent of Ca(OH)₂ and their strengths were tested. The second set of specimens was similarly mixed with 2, 4 & 6 percent of Ca(OH)₂ but in this case treated with CO₂ and then their strengths were tested. The CO₂ treatment was made on the compacted soil. The properties chosen for comparison were the load carrying capacity, cohesion and angle of internal friction. After the above mentioned experiments were complete, adequate amount of 6 percent lime added samples were prepared. This time they were treated with CO₂ and then compacted. The purpose was to see whether treating the specimens with CO₂ before or after compaction had any effects on the characteristics of the soil"--Introduction, leaves 1-2. |
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