Compaction Test - Lab Report Example

compaction should never be confused for compression, consolidation, sheer or creep which are processes of volume change for the soil. On the other hand, a dry density obtained through impacting of energy on the soil relies on the first initial content of water which is referred to as the molding content of water. Getting to know the relationship between the moulding content of water and the achievable density is a topic that has been of concern for many years. The dry condition and a moulding content water increase could lead to high dry density compaction. The trend will continue until the maximum dry density is achieved at an optimum water content moulding. As the water increases, there would be a continuous dry density reduction. Such a reaction would be referred to as the curve of compaction. In order to gain a deeper insight concerning compaction, this experiment was set to investigate the compaction test.

Procedure.
The sample mould base and mould mass would be determined to the nearest gram. The mould diameter and depth were measured. The mould depth was about 3 places whereas the moulding diameter was about 6 places + or- 0.02 mm. The hammer, mass, proper drop, and square edges were checked for damages. Well-graded sand with fines that are less than five percent was used to ease the laboratory instruction. A material with particles that are oversize was selected to show the test aspects. Enough moist material was selected to give out approximately 12 kg of soil that is dry. The natural content of water was obtained.

The number of materials needed for the point of compaction was estimated. Five samples having contents of water separated by 1.5 percent were prepared. The water contents were adjusted such that they bracket the value that was optimum. The soil was tempered overnight to reduce the scatter in the data thus making it easy to define the curve of compaction. The compaction test was done with respect to the standards of the ASTM test method D698, even though D1557 could be used instead of minor modifications. The mould was assembled and clamped to the base of the solid or floor. Each specimen was compacted in three equal layers by using twenty-five blows in each layer. The top surface of the layer that is underlying was scarified with a knife to approximately three-millimeter depth before the compaction of the third and second layers.

The final layer completely filled the mold and did not exceed the mold by more than six millimeters. Each layer was compacted through the use of the recommended hammer drop sequence that ensured uniformity in the energy. The compaction collar was removed and checked to confirm that the soil surface was not too high. The surface of the soil was extended above the mold top but less than or equal to six millimeters. After this, the surface was scraped flat using a knife and using the mold top as a guide. The mass of the mold and the specimen was determined. The specimen was extruded through the use of a hydraulic jack. A representative content of water for the specimen was obtained. The pie-shaped slice was cut through a whole specimen.

The test is used to measure the density changes that were obtained under certain energy and over different contents of water. The water of moulding and the obtained dry densities came about due to applying an equal quantity of energy to about six specimens that were made at various contents of water. The content of water and the amount of energy that is utilized in compacting a certain soil possess a significant effect on the final engineering properties. On the optimum dry side, the material is considered to be stronger and stiffer and possesses a high conductivity (Proctor 12). When the dry density reaches the maximum dry density, the properties of engineering of such a material would generally improve. In this respect, the strength would be high and the compressibility, conductivity, and brittleness reduced. Such principles can be applied in dam density, construction of highways, containment of hazardous waste, and the reconstitution of laboratory specimens (Proctor 7). Read More