Sand Equivalent Value Test
The purpose of the sand equivalent value test is to ascertain the percentage of unwanted particles in the aggregate fraction utilized in the manufacturing of concrete mixtures of Portland cement. The method is also suitable for ascertaining the related amount of harmful clay like materials of fine dust in the soil.
Equipment And Materials
The test kit for Sand Equivalent consists of the following –
- Graduated plastic cylinder
- Rubber stopper
- Irrigation tube
- Mechanical sand equivalent shaker
- Stock calcium chloride solution
- Four measuring tins having a diameter
- Se-Test measuring diameter approximately 57 mm (2. inches) and a capacity of (110 ml) 85%/5 ml
- 75-mm (No. 4) sieve
- Fine aggregate
- 78-liter (1 gallon) bottle
Procedure of the Test
- Have a sample of the aggregate passing the No. 4 (4.75 mm) sieve. oven dried and room temperature condition, before testing. splitting approximately 1500 grams.
- Tap calcium chloride 4.0 inches (101.6 mm) of solution into a plastic cylinder. Se-Test pour one of the prepared specimens into the plastic cylinder using the funnel to avoid spillage and bottom of the cylinder sharply by hand to release any air bubbles.
- Se-Test stopper on the cylinder and vigorously shake it manually to loosen the material And Place the cylinder in the mechanical sand equivalent shaker, set the timer, and allow the machine to run for 45 seconds.
- sample of the aggregate passing continue this irrigation process until the cylinder is filled to the 381-mm (15-inch) mark.
- Se-Test India irrigator slowly without shutting off the flow so that the liquid level is maintained at about 381 mm (15 inches) while the irrigator is being withdrawn. Sand Equivalent Value Test Regulate the flow just before the irrigation is entirely withdrawn and adjust the final level to 381 mm (15 inches).
- Now make sure to pour sample of the test into the cylinder from the from the measuring tin using a funnel Tap
- Allow the wet sample to sit for approx. 10 – 12 minutes.
- Se-Test supplied through the siphon assembly to a 3.78-liter (1 gallon) bottle of working calcium chloride solution placed on a shelf about 1 meter (3 feet ± 1 inch) above the work surface. Allow the cylinder to now stand undisturbed for 20 minutes and start the timing immediately after withdrawing the irrigator tube, at the end of the 20-minute sedimentation, read and record the top of the clay suspension. This is referred to as the clay reading. If no clear line of demarcation has formed at the top of the 20-minute amount, allow the cylinder to stand undisturbed till a clay reading may be obtained.
- Shake the sample through one of the following methods, i.e. via hand, mechanical shaker or manually.
- Irrigate the sample and place an irrigator tube into the sample and use the irrigation to wash the sample off the cylinder walls as the tube is lowered.
- Heighten the irrigation tube out of the cylinder to allow the liquid to stay at 381 mm mark
- Keep the cylinder with sample undisturbed for 25 minutes
- Immediately read and record the level of the top of the clay suspension and the total suspension time. If the total sedimentation time exceeds 30 minutes, rerun the test on the other prepared samples of the same material. Read and record the clay column height of the specimen requiring the shortest geological phenomenon amount solely.
- Se-Test clay reading has been taken, place the weighted foot assembly into the cylinder and lower it gently until it comes to rest on the top of the sand. Be careful to not hit the mouth of the cylinder with the weighted foot assembly. Tip the assembly toward the graduations on the cylinder till the indicator touches the within wall of the cylinder. Subtract 25.4 cm (10 in.) from the level indicated by the extreme top edge of the indicator and record this as the sand reading. Please don ‘t apply pressure to the assembly at any timed
- Now lastly, record the level at the peak of the clay stay.
Sand Equivalent Value Test Calculation
Se-Test Sand Equivalent Value result always carrying the sand equivalent (SE) up to the next higher whole number (do not use any decimals). If more than one Se-test India is made, take the average of each whole number value for each test specimen to the next higher whole number. Use 2.5 mm (0.1 in.) as the smallest unit for the readings and always use the higher graduation if the readings fall between one-tenth inch marks. Calculate the sand equivalent to the nearest 0.1% using the Sand Equivalent consists following formula:
SE= (Sand Reading/Clay Reading)*100%
Cleaner aggregates will have a higher SE value. Specifications typically need a minimum SE on the order of twenty five to thirty fifth.