AASHTO T290-95 pdf free download

AASHTO T290-95 pdf free download.Determining Water- Soluble Sulfate lon Content in Soil.
SCOPE
This method covers the dry preparation of soil and soil-aggregate samples, as received from the field, for use in determining the sulfate ion content in soils.
4.2. The following applies to all specified limits in this standard: For the purpose of determining conformance with these specifications, an observed value or calculated value shall be rounded ofT “to the nearest unit” in the last right-hand place of figures used in expressing the limiting value, in accordance with ASTM E29.
APPARATUS
The balance shall have sufficient capacity, he readable to 0.1 percent of the sample mass or better, and conform to the requirements of M 231.
5.2. Drying Apparatus—Any suitable device capable of drying samples at a temperature not exceeding
60°C (140°F).
5.3. Sieves—A series of sieves of the following sizes: 6.3 mm (1/4 in.), 4.75 mm (No. 4), 2.00 mm (No. 10), and a pan. The sieve shall conform to M 92, Wire-Cloth Sieves for Testing Purposes (Note 1).
Note 1—The sieve sizes that have an opening size of 6.3 mm (1/4 in.) or larger shall conform to the requirements specified in M 92, excluding Column No. 7. This exclusion permits the use of heavier screens in nonstandard frames that are larger than the 203.2-mm (8-in.) round frames.
5.4. Pulverizing Apparatus—Either a mortar and rubber-covered pestle or any device suitable for breaking up the aggregations of soil particles without reducing the size of the individual grains (Note 2).
Note 2—Other types of apparatus are satisfactory if the aggregations of soil particles are broken up without reducing the size of the individual grains.
5.5. Sample Splitter—A suitable riffle sampler or sample splitter for proportional splitting of the sample and capable of obtaining representative portions of the sample without appreciable loss of lines. The width of the container used to feed the riffle sampler splitter should be equal to the total combined width of the riffle chutes. Proportional splitting of the sample on a canvas cloth is also permitted.
7.1. The sample as received from the field may be dried in air or a drying apparatus not exceeding
60°C (140°F) prior to sample selection (Note 3). A representative test sample of the amount required to perform the tests shall then be obtained with the sampler, or by splitting or quartering. The aggregations of soil particles shall then be broken up in the pulverizing apparatus in such a way as to avoid reducing the natural size of the individual particles.
Note 3—Samples dried in an oven or other drying apparatus at a temperature not exceeding 60°C (140°F) are considered to be air dried.
7.2. The portion of the sample selected for sulfate testing shall be separated into fractions by one of the following methods:
7.2.1. Alternate Method Using 2.00-mm (No. 10) Sieve—The dried sample shall be separated into two fractions using a 2.00-mm sieve. The traction retained on the sieve shall be ground with the pulverizing apparatus until the aggregation of soil particles is separated into individual grains. The ground soil shall then he separated into two fractions using the 2.00-mm sieve.AASHTO T290-95 pdf download.