Category:1124 Sodium Chloride

This article establishes procedures for inspecting and sampling sodium chloride (rock salt) for use as deicing material. The requirements are set forth in the bid request issued by MoDOT.

Sodium chloride furnished shall arrive at destination in a free-flowing and usable condition and be free from objectionable material.

1124.1 Apparatus

Sample containers for submitting samples to the Laboratory shall be one-quart (1 liter) friction top cans. All containers and equipment shall be clean, dry and free of all contaminants.

1124.2 Procedure

1124.2.1 Inspection

The first shipment per supplier per district on a purchase order shall be sampled and the gradation determined in accordance with 1001.4.1 Sieve Analysis. If the gradation complies with the requirements of the specifications, a sample shall be submitted to the Laboratory for chemical analysis.

If the sample fails to meet gradation requirements, two additional samples shall be obtained and tested. Both of the additional samples must meet gradation requirements or the lot represented by the samples will be rejected.

Additional shipments shall be sampled and tested for gradation at the minimum rate of 1 per 1000 tons (900 Mg) per supplier per district. Samples for chloride content shall be submitted to the Laboratory at the rate of 1 per 5000 tons (4500 Mg) per supplier per district.

1124.2.2 Sampling

A composite sample of approximately 30 pounds (12 kg) shall be taken from a minimum of six locations of the shipment. Each location sampled shall have the upper 3 in. (75 mm) scraped aside and approximately a 5 lb. (2 kg) sample taken by means of a sample thief or by other suitable means. All samples shall be combined and split down by means of a standard aggregate splitter to obtain approximately 1 1/2 kg for field gradation and 1 quart (1 liter) for laboratory analysis.

The sample to be submitted to the Laboratory shall consist of approximately one quart (1 liter) of material in a friction top can.

1124.3 Report

Sodium chloride sampled and submitted to the Laboratory will be reported in accordance with 1124.4 Laboratory Testing Guidelines. Form T-634 shall be used for field reporting of sodium chloride. Invoice number or other identification as well as quantities, are to be shown. Loads that are not tested may be accepted on the basis of visual inspection at the discretion of the district Operations Engineer. All field reports shall include the last Laboratory number under which the chemical composition was tested and accepted. The report is to indicate acceptance, or rejection. Appropriate remarks, as described in The Rounding Off Method, are to be included in the report to clarify conditions of acceptance or rejection.

All shipments are to be field reported by the district.

1124.4 Laboratory Testing Guidelines

To establish procedures for Laboratory testing and reporting samples of sodium chloride for use as a deicer. The requirements are set forth in the bid request issued by MoDOT.

1124.4.1 Procedure

Chemical analysis of sodium chloride shall be conducted in accordance with 106.7.32 TM-32, Determination of Purity of Sodium Chloride. Original test data and calculations shall be recorded in Laboratory workbooks. Test results and field gradation shall then be recorded through SiteManager.

1124.4.2 Sample Record

The sample record shall be completed in SiteManager, as described in Automation Section 3510, and shall indicate acceptance, qualified acceptance, or rejection. Appropriate remarks, as described in 106.9 Reporting Test Results, are to be included in the remarks to clarify conditions of acceptance or rejection. Test results shall be reported on the appropriate templates under the Tests tab.