Sand Equivalent Test

What Is Sand Equivalent?

The sand equivalent test is a fast subject test to show the relative proportions of excellent dust or clay-like materials in nice combination (or granular soils). The term “sand equivalent” expresses the idea that most pleasant aggregates are combos of proper coarse debris (e.g. sand) and normally undesirable clay or plastic fines and dirt (ASTM).These materials can coat combination debris and prevent right asphalt binder-combination bonding. In the sand equivalent test, a sample of combination passing the No. 4 (4.seventy five mm) sieve and a small quantity of flocculating answer are poured right into a graduated cylinder. The pattern is then irrigated with extra flocculating solution forcing the clay-like fabric into suspension above the sand. After a prescribed sedimentation period, the peak of flocculated clay and height of sand are decided and the sand equal is expressed as a ratio of the height of sand over the height of clay. Higher sand equivalent values indicate “cleaner” (less first-rate dirt or clay-like materials) combination.

Apparatus:

Graduated cylinder = Inside diameter = 1.25-in (31.8-mm), Height = 17-in (432-mm)

Graduated up = 15 in (381 mm), Intervals = 0.1 in. (2.5 mm), starting at the base.

Rubber stopper = is used to fit the mouth of the graduated cylinder.

Agitator tube = brass, stainless steel, or copper; 20 in. (508 mm) long

Weighted foot assembly  = consisting of a metal rod connected to a foot with a flat, smooth surface on the lower end and a weight on the upper cease to offer the whole assembly a weight

Assembly with sand reading indicator = sand studying indicator attached on the rod 10 in, above the bottom of the foot.

Assembly without a sand analyzing indicator = the foot has three small screws to middle it loosely within the cylinder. A bored cap fits loosely across the rod at the pinnacle of the cylinder to center the weighted foot assembly inside the cylinder. The weight of this cover is not part of the total weight of the assembly.

Glass bottle = 1 gal (3.79 L)

Tubing = 4 ft (1.22 m) (1. 22 m) long, plastic or rubbers, with pinch clamp to attach the open give up of the agitator tube with the siphon assembly.

Standard U.S. Sieve =  No # 4 (e.g. 4.75 mm), meeting the requirements

Measuring CAN = 85 mL (3 fl. oz.)

Wide mouth funnel and Stopwatch, watch

Glass cylinder = 100 mL

Drying oven =  capable of maintaining 60 ± 3°C and 110 ± 5°C

Motor-driven mechanical sand equivalent shaker, Straight edge or spatula.

Splitter or quartering device

Procedure Of Sand Equivalent:

Sand Equivalent Test Equipment

When we start to examine the sand equivalent test for mixture used for bituminous materials, including hot blend asphalt, hot-blend cold-laid, and others micro surfacing. Dry the test sample in an Oven with steady weight at 110 ± 5 °C. Oven-dry pattern of limestone rock asphalt aggregates at 60 ± 3 °C. Tests on damp samples will typically give decrease values than assessments on oven-dried samples. It is permissible now not to dry the pattern to store time, but if the test values are close to or underneath the required minimal, then retest the sample inside the oven-dry condition. After drying in Oven then cast off sample from oven and allows it to cool to room temperature. Using the No. 4 (4.75 mm) sieve, separate the sample into portions, breaking apart lumps that encompass particles obviously finer that the No. 4 (4.75 mm) sieve.

Graduated Cylinder With Sample

When we start to examine the sand equivalent test for mixture used for bituminous materials, including hot blend asphalt, hot-blend cold-laid, and others micro surfacing. Dry the test sample in an Oven with steady weight at 110 ± 5 °C. Oven-dry pattern of limestone rock asphalt aggregates at 60 ± 3 °C. Tests on damp samples will typically give decrease values than assessments on oven-dried samples. It is permissible now not to dry the pattern to store time, but if the test values are close to or underneath the required minimal, then retest the sample inside the oven-dry condition. After drying in Oven then cast off sample from oven and allows it to cool to room temperature. Using the No. 4 (4.75 mm) sieve, separate the sample into portions, breaking apart lumps that encompass particles obviously finer that the No. 4 (4.75 mm) sieve.

Secure the sand equivalent take a look at pattern from the element passing the No. 4 (4.75 mm) sieve by cautiously reducing the amount of cloth to laboratory test size.

Split or area the material to attain a minimum 500-g pattern, to make certain consultant samples when running with a fabric that is predominantly coarse No. 4 (4.75 mm) to No. 8 (2.36 mm), separate the sample into sizes No. 4 (4.75 mm) to No. 8 (2.36 mm) and minus No. 8 (2.36 mm), after which recombine the cloth in proper proportions to provide a uniform sample. Strike off the extra cloth the usage of a straight aspect or spatula. Do now not compact the sample prior to putting it off.

Performing the Sand Equivalent Test:

The sample is placed in the measuring CAN then transfer the sample into the plastic cylinder by using the small funnel.

Siphon 4 (0.1 in) is used to transfer liquid of calcium chloride solution into the plastic cylinder. Check the agitator tube to be certain that the solution flows freely. Then stopper the cylinder. After this process keep the cylinder with whole contents in undisturbed place, free of any vibration, for approximately 10 minutes. 

Mechanical shaker: Set the timer and shake for 45 seconds.

Manual shaker:  Place the cylinder in a manual shaker and shake for 100 cycles.

Hand:  Shake the cylinder by hand in a horizontal linear motion for 96 cycles, and remove the stopper, to wash the wall of cylinder into the mixture, using a minimum amount of solution. Replace stopper in the end of cylinder. Wash down the cylinder wall with the solution.

Continue smoothly jabbing the agitator tube up and down with a mild twisting motion at the same time as slowly rotating the cylinder in a vertical role to flush the fine clay-like material into suspension above the coarse sand Continue the operation till the cylinder is crammed to the 15 in. (381 mm) mark.

Slowly remove the agitator tube without shutting off the flow, so the level of the liquid is maintained at 15 in. (381 mm).

Regulate the glide of the answer and regulate the extent of way to 15 in.when the agitator tube is absolutely withdrawn. Allow the cylinder and contents to face undisturbed for 20 minutes. Start the timing straight away after the elimination of the agitator tube.

Settlement Of Sediments 

After the 20-minutes the sediments are settled down, read the extent of the pinnacle of the clay suspension and report the reading.

If there's no clean line of clay meniscus at the stop of the given time of sediments settling, maintain permitting the fabric to stand undisturbed until the division is clean.

Read and document the level of the clay layer and the total sedimentation time.

When using the weighted foot assembly with sand analyzing indicator, gently lower the foot meeting into the cylinder until it comes to relaxation at the sand. Very lightly tilt the assembly until the indicator touches the commencement marks at the cylinder. Tilt meeting lower back to vertical before taking analyzing. Read the extent indicated with the aid of the pinnacle fringe of the indicator and subtract 10 in. (254 mm). Record this reading because the sand analyzing.

Calculation Of Sand Equivalent Test:

To calculate the values of sand equivalent test is closely by 0.1 inch

Formula Of SE:

                                SE    =    Sand / Clay  *  100

For Example,

                     SE    =     3.1 / 6.9  *  100       =       44.9

It can be written as 45.