2 labs reports in 12 hours only 2 pages each

Lab 5. Standard Proctor Compaction Test (Lab10 in 9th, Lab 12 in 8th ) The degree of compaction of a soil is measured by its dry unit weight(γd).

The dry unit weight of compaction increases as the moisture content increases until w=wopt. Beyond w=wopt, any increase in moisture content tends to reduce the dry unit weight.

Used to determine the optimum moisture content at which a given soil type will become most dense and achieve its maximum dry unit weight

Figure 10-6 Plots of γd vs. w(%) and γzav vs. w(%) For test results reported in Tables 10-1 and 10-2

Procedures

The moisture content of soil A is about 3.35%, that of soil B is 2.46%, and that of soil C is about 2.28%.

Start the experiment by adding water to bring the moisture content up to about 7% and then increase the moisture content by 2 % for each trial

Continue the test until at least two successive down readings of W2 (weight of mold+base plate+moist soil) are obtained.

Three equal layers Compact each layer by 25 times

Water Content of Soil 𝑤(%) = 𝑀𝑤𝑀𝑠 × 100

Amount of water to add

𝑀𝑤(𝑖𝑛 𝑚𝑙) = ( 𝑀𝑠(𝑖𝑛 𝑙𝑏)×𝑤

100 )( 453.6𝑔 1 𝑙𝑏 )

If Ms = 6 lb and w=5%, 𝑀𝑤 = (

6×5 100)(

453.6𝑔 1 𝑙𝑏 ) = 136.1𝑔 ≈ 136𝑚𝑙

Lab Report (see section 10.8 in your textbook)

– Results section should include data tables for compaction test and for zero-air-void unit weight calculation, sample calculations, and the graph for plots of γd and γzav vs. w.

– Report γd(max) and wopt.

– In discussion section, estimate γd(max) and wopt using Eqs. (10.8) and (10.10) and compare with those obtained from the lab. Discuss any discrepancy between the observed and estimated values. Discuss any sources of error.

Gs of soil A (Group A&B&C) is 2.45, Gs of soil B (Group D&E) is 2.72, and Gs of soil C (Group F) is 2.50.