How do you test soil compaction?
Soil compaction occurs below the surface, so it’s hard to spot. The best way to test is to probe the soil with a compaction tester to a depth of 36″ to 48″. The testing rod should move down through the soil with steady, even pressure, Hard, compacted soils resist penetration with the rod.
How is compaction measured?
Compaction is achieved by applying a pre s s u re on the surface or by vibrating the soil mass. To find out how well a soil has been compacted we must measure the dry unit weight or dry density in pounds per cubic foot. Dry density is a measure of the weight of solid material present in a cubic foot of soil.
What two laboratory tests are used to define soil compaction?
The most commonly used laboratory test is called the Proctor compaction test and there are two different methods in obtaining the maximum density. They are the standard Proctor and modified Proctor tests; the modified Proctor is more commonly used. For small dams, the standard Proctor may still be the reference.
What is a passing compaction test?
The Proctor Compaction Test establishes the maximum unit weight that a particular type of soil can be compacted to using a controlled compactive force at an optimum water content. In-place measured densities of the compacted fill are compared to the Proctor test results to determine the degree of soil density.
How many types of compaction tests are there?
How do you get 98 compaction?
98% compaction is simply the result of the comparison between field values and lab values for a specific soil. 98% compaction just means that the density of the material placed on site is 98% of the maximum density determined in the lab.
What is the acceptable percentage of compaction?
As long as the compaction percentage stays below about 105%, it is fine. When it goes up to the 105% range, it indicates you’re likely working in a material that is different than your Proctor material.
Why compaction test is done?
What is the purpose of the compaction test? The test aims to establish the maximum dry density that may be attained for a given soil with a standard amount of compaction effort. When a series of soil samples are compacted at different water content, the plot usually shows a peak.
What is the name of compaction test?
Proctor Compaction Test
Proctor Compaction Test. The most common laboratory test for soil compaction is the Proctor compaction test. The Proctor test was invented in the 1930s by R. R.
What does 95% Proctor density mean?
For example, specifications often require compaction to be 95 percent of Standard Proctor. This means the on-site soil density must be equal to 95% of the maximum achievable compaction. • Compaction is achieved by applying three basic types of force to the soil mass.
How do you do a soil compaction test?
Place the soil in the mixer and gradually add water to reach the desired moisture content (w). Apply lubricant to the collar. Remove the soil from the mixer and place it in the mold in 3 layers or 5 layers depending on the method utilized (Standard Proctor or Modified Proctor).
How is earthfill compacted in Class C compaction?
Class C compaction—Each layer of earthfill shall be compacted by the specified number of passes of the type and weight of roller or other equipment specified or by an approved equivalent method. Each pass shall
How to calculate zero voids in soil compaction test?
The zero-voids curve is calculated as follows: where: GS = the specific gravity of soil particles (typically, G S ~2.70) γW = the saturated unit weight of the soil (kN/m 3) Typical curves derived from the Standard and Modified Proctor tests, as well as the zero air voids curve are presented in Figure 4.
What do you need to know about backfill and compaction?
Field Density of Soil : Earth backfilling to be done with Proper consolidation, compacted at optimum moisture content to a minimum of 95% standard proctor density or Field dry density FDD for all i) Footings up to top level, ii) Inside and Outside Plinth and iii) Below Granular sub base (GSB) level.
