Sand Patch Test

SAND PATCH TEST

INTRODUCTION Level 2 laboratory activities refer to the condition where only the problem is guided and given. Students are required to find the ways & means and provide the answers to the given assignment using the group creativity and innovativeness. The activity will enable the students to appreciate independent learning and prepare them for a much harder task of open ended laboratory activities. In this partially open laboratory activity the students are required to carry out a study to determine the depth of surface texture at a particular location.

OBJECTIVE To measure the average depth of the surface texture of an asphaltic concrete pavement.

THEORETICAL BACKGROUND Sample site should normally be selected by a random sampling technique. Ensure that the pavement surface is clear of dirt and debris by sweeping the surface with a small brush. The test area is to be clear of surface cracking. The pavement surface must be dry to achieve satisfactory results. The average texture depth may be calculated by dividing the volume of sand by the area of the sand patch.

Texture depth (mm) =

4V x 103 2 πd

where : d = average diameter of sand patch circle (mm) V = volume of sand used (usually 50 or 100 cm3)

PROBLEM STATEMENT Texture is a surface characteristic which has a very wide influence on pavements functional quality. For new road surface, it is recommended that sand patch test for compliance checking should be carried out prior to opening to traffic including construction traffic. Your group has been appointed to conduct a highway assessment in order to measure the average depth of surface texture and discuss on the result. The location of the study is randomly selected in the campus area of UiTM Pasir Gudang

APPARATUS  Sand  Measuring beaker  Ruler  Spreader disc with surface covered by rubber  Wooden brush

PROCEDURE 1. Select the spot on the road to be tested, normally in the nearside wheel track. The surface of the pavement is cleaned from any sand or small stone by using the wooden brush. 2. Pour 30ml of sand into the measuring cylinder and pour on the road surface. 3. By using the spreader disk, spread the sand in a circular direction until the sand were spread evenly. 4. The diameter of the sand were measured and recorded in the table. 5. Take the diameter of the sand 3 different direction and take the average. 6. Repeat the step in 3 different pleace.

Result Location

Volume Of Sand, V (cm3)

Left

30.0

Centre

30.0

Right

30.0

Analysis Left 2

V=

πd h 4

h=

4V π d2

h=

4 (30) π 20.62

h=0.090 cm Centre 2

V=

πd h 4

h=

4V π d2

h=

4 (30) π 21.92

h=0.080 cm Right

Diameter, d (cm) 21.0 20.0 20.0 21.5 19.0 24.0 23.0 21.5 17.9 22.5 21.4 21.5

Average Diameter, d (cm)

Depth, h (cm)

20.6

0.090

21.9

0.080

20.8

0.088

2

V=

πd h 4

h=

4V π d2

h=

4 (30) π 20.82

h=0.088 cm