Control of materials involves TxDOT field, district, Materials and Tests Division (MTD) central laboratories, and commercial and manufacturer’s laboratories. Post the District Sourcing Letter (DSL), which lists material suppliers, as soon as possible so that proper arrangements can be made for sampling and testing of the various materials. Instruct the Contractor to order materials sufficiently in advance of related work to allow time for sampling and testing. In addition, instruct the Contractor to identify the project and the contract item number on all materials orders.

Accept only those materials that comply with the contract requirements. Maintain records of the test results that substantiate acceptance or rejection of the materials. Record both failing and passing tests with documentation of the disposition of the failing material (reworked, retested, disposed of, etc.)

Contract specifications identify which tests are used for each material. The sampling and control of materials are as outlined in the appropriate testing procedures and the (the Guide Schedule). Apply tolerances specified in the contract in determining acceptance of the work.

Sample materials for testing at the locations and frequencies shown in the Guide Schedule. The test procedures do not generally specify sampling points. Establish locations to receive the samples when there are no established sites. Notify the Contractor of the sampling points as soon as possible to provide opportunity to make corrections when the materials do not meet the contract requirements. Determine if stockpiled materials are acceptable prior to payment as Material on Hand (MOH).

Article 6.4

"Sampling, Testing and Inspection"

, of the states:

“All materials used are subject to inspection or testing at any time during preparation or use. Material which has been tested and approved at a supply source or staging area may be inspected or tested before or during incorporation into the work and rejected if it does not meet Contract requirements. Copies of test results are available upon request. Do not use material that, after approval, becomes unfit for use.”

Ensure that the method and location of materials sampling is consistent and uniform. Retest previously accepted materials if the material shows visible changes, does not conform to specifications, or if further testing is required by the contract or Guide Schedule. The contains additional information on sampling and testing responsibilities.