Discussion Theory Field Density testing using Sand Replacement method is the industry standard in field density soil testing. This test is used to determine the field wet density, field field moisture content and Field Dry Density of any given soil. PDF… Observation
During the experiment, the field chosen was tested using sand replacement method. y digging a cylindrical hole in the field, we were a!le to get field samples for testing. Sand is used in filling up the hole to measure the volume of the soil sample ac"uired. The idea is that, !y #nowing the density and the weight of the sand, it is possi!le to compute its volume. $n o!serving the procedures, one source of error is the no uniformity of the sand used. The sand particles must have uniform particle si%es to ensure accurate volume calculations. The reason for this is that, when the sand is not uniform in si%e, there is also n o uniformity in its density and thus creating errors in the experiment. The amount of soil removed from the hole should !e ta#en without spilling. $t affects the result of the experiment to !e inaccurate. This is !ecause the spilled soil should have contri!uted to the overall weight of the field soi l removed. &hen the weight of soil sample is not as much as the volume of the hole should supposedly weigh, this causes ma'or errors in the data. &hen pouring the sand into the hole, it should !e monitored properly !ecause unexpectedly, sand particles might clog on the cone disallowing the sand to pour freely. (o external forced should !e directed in the cone when pouring the sand !ecause this might cause overflow in the hole. Application
Field Density Testing )(uclear or Sand *one+ is performed in the field during construction on soil that is !eing placed in a fill and must provide a sufficient level of compaction to support a structure or roadway. This test compares the a!oratory *ompaction Density to the Field Density in order to determine the percent compaction achieved. The in-situ density of the soil is re"uired to control the results of field compaction in earth em!an#ments, Road fill and structural !ac# filling. So, measuring the soil density is essential !efore !uilding any construction. Three methods are used to determine the density )unit weight+ of a soil in the sight the sand replacement method, the !alloon method, and the nuclear method. During the course of a large earthwor# pro'ect in /eorgia, six test fills were constructed to study placement and compac compactio tion n proced procedure ures. s. Severa Severall densit density y testin testing g techni" techni"ues ues used used in the "ualit "uality y contro controll testin testing g progra program m were were compared. 0 la!oratory compaction test was performed at each field density test location to eliminate the need to select the appropriate compaction curve from a family of curves. Two soil types, !oth sands, were involved in the test program. The effects of gradation, compaction, mold si%e, depth of density test, and type of nuclear device were investigated. 1aria!les in construction procedures included type of e"uipment, num!er of passes, lift thic#ness, and soil type. Following a statistical evaluation it was concluded that )2+ oven moisture contents were consistently lower than nuclear moistures, )3+ nuclear wet densities were always less than sand cone densities, and )4+ the sand cone density test method yielded a 56 higher compaction when compared to the nuclear test method. Conclusion
0t the end of the experiment, it is conclusive that the test can determine density of the upper layer of compacted soil only and not appropriate to test for material with particle si%e over 3 inches )57.8 mm+. 9uality control of soil compaction in the field is to ensure that properties of soil conform to the specification. $n-place density of soil and water content are commonly used as compaction "uality control parameters. Field density test !y sand-cone method is widely used to determine these parameters. 1olume of compacted soil is measured indirectly
!y replacement of standard sand into the test hole. Soil density then calculated !y dividing the weight of soil removed !y volume of the hole. 0dvantages of this test includes that it is fast and easy to perform and Parameters o!tained from the test can also !e used for other purposes. Recommendation for the test include consideration for minimum test hole volume and minimum moisture content samples should depend on maximum particle si%e of compacted materials. (um!er of test location depends on the uniformity of the compaction and other factor. Design engineer should determine num!er of test location and review the results. The test should give in:place wet d ensity, dry density and degree of compaction.
