Question

A series of Proctor compaction tests were performed on fill material used for a roadway application. The results are shown in the Table below.

Data Point No.	1	2	3	4	5
Mass of compacted soil + mould (kg)	3.762	3.921	4.034	4.091	4.04
Moisture content, w (%)	4.5	7.5	10.1	12.9	16.4

 

The mass of the compaction mould was 2.031 kg. The mould volume was 1×10^–3 m³.

(a) Compute dry unit weight g_d for each data point.

 

(b) Draw the Proctor compaction curve of the soil, and determine the maximum dry unit weight g_{d max} and optimum moisture content w_opt.

 

(c) Determine the degree of saturation at g_{d max} using a specific gravity of solids G_s of 2.65 and g_w = 9.81 kN/m³.

 

(d) A field density test has been conducted in the roadway. The test results indicate the field dry unit weight is 106 % of the g_{d max}. Determine whether the tested section should be passed or not. What advice would you give to the earthworks contractor who is constructing the road?  (No more than three sentences are required).