A02 Performance Work Statement - Laboratory Testing of Aggregate Samples V1.pdf

PERFORMANCE WORK STATEMENT

Contract Description: Laboratory Testing of Aggregate Samples

Background:

The US Army Engineer Research and Development Center (ERDC) has been conducting research on transportation infrastructure to support the United States Department of Defense (DoD) for many years.

The ERDC performs research and development of materials and specifications for the design, construction, evaluation, and analysis of airfield pavement systems. The Airfields and Pavements Branch (APB) has been tasked to investigate the influence of mineral aggregates in the properties of asphalt concrete materials to improve the performance of asphalt pavements. As part of this research, USACE standardized laboratory test methods have been conducted on a representative number of aggregate sources and types. To complement the ongoing research, alternative laboratory test protocols must be performed to characterize the mineral aggregates considering other forms of distresses such as durability, weathering, strength, and crushability.

Objectives:

The overall objective of this effort is to assess alternative properties of mineral aggregates that are commonly used to produce asphalt concrete material for airfield paving projects. The assessment of mineral aggregates will be carried out by performing various advanced laboratory tests to evaluate durability, weathering, strength, and crushability. Results collected through this service contract and ongoing research at ERDC will be used collectively to inform recommendations regarding specification requirements for the selection and use of mineral aggregates in asphalt concrete materials.

Technical Requirements and Services:

The laboratory that conducts the testing should be certified by the U.S. Army Corps of Engineers Materials Test Center. The laboratory samples to be tested are sensitive to damage and must be hand delivered so the vendor should be within a 2-hr. driving time of the ERDC Vicksburg campus to minimize driving time and eliminate TDY costs.

The available aggregate material has been processed (i.e., washed, dried, and separated into individual sizes) for further laboratory testing. Aggregate samples, as required by each test method, will be delivered to the vendor for testing. The POC shall be made available to answer any questions regarding test set up and procedures.

Table 1 summarizes the number of test methods and aggregate samples that must be tested under this service contract. The test methods shall follow standardized specifications (e.g., ASTM, AASTHO, etc.)

unless noted in the description of the test methods provided next.

Test Method 1: Sulfate Soundness Test. This test method must be performed using the two solutions, magnesium sulfate and sodium sulfate. The aggregate sample will consist of 300 g of aggregates passing 3/8 in. sieve and retained on No. 4 in. One test sample shall be tested per aggregate type and solution.

Test Method 2: Coarse Aggregate Specific Gravity. This test method shall be performed as outlined in the ASTM standard. The aggregate sample will consist of 2000 g of aggregates passing 1/2 in. sieve and retained on 3/8 in. One test sample shall be tested per aggregate type.

Test Method 3: Methylene Blue Test. This test method shall be performed as outlined in the ASTM standard. No modifications will be requested. One test sample shall be tested per aggregate type.

Test Method 4: Uncompacted Voids in Coarse Aggregate. This test method shall be performed as outlined in the ASTM standard. No modifications will be requested. The test will be conducted using (Method B for an individual size fraction consisting of 1/2 in. to 3/8 in. aggregate size. Three data points from a test sample shall be collected per aggregate type.

Test Method 5: Compacted Voids in Coarse Aggregate. This test method shall be performed using the measure specified in AASHTO T 326. The aggregate sample shall be compacted in three layers by applying 25 blows per layer. Three data points from a test sample shall be tested per aggregate type.

Test Method 6: Aggregate Durability Index. This test method shall be performed as outlined in the ASTM standard. No modifications will be requested. Three test sample shall be tested per aggregate type.

Test Method 7: Modified Slake Durability. This test method shall be performed using the equipment specified in the ASTM standard. Instead of water, use a magnesium sulfate solution. The aggregate samples size will be 300 g of material passing 3/8 in. and retained on No. 4 in. sieve. The testing time shall consist of 16 hrs. in the apparatus (the material is submerged and rotating). After each cycle the material shall be washed and dried. The test shall consist of 3 consecutive cycles. Mass loss must be recorded after each cycle.

Test Method 8: Aggregate Impact Value. This test method shall be performed as outlined in the BS 812- 112 standard. The crushed material should be sieved through 3/8 in., No. 4, and No 8 sieves, and the retained weights must be recorded including the amount of material passing No. 8 sieve. Three test samples shall be tested per aggregate type at dry and wet condition.

Test Method 9: Aggregate Crushing Value. This test method shall be performed as outlined in the BS 812-112 standard. The crushed material shall be sieved through 3/8 in., No. 4, and No 8 sieves, and the retained weights must be recorded including the amount of material passing No. 8 sieve. Three test samples shall be tested per aggregate type.

Table 1. List of tests to be conducted.

Test No. Test Description Test Standard Aggregate

Quantity 1 Sulfate Soundness Test ASTM C88 15 2 Coarse Aggregate Specific Gravity ASTM C127 15 3 Methylene Blue Test ASTM C1777 25 4 Uncompacted Voids in Coarse Aggregate AASHTO T 326 10 5 Compacted Voids in Coarse Aggregate AASHTO T 326 (Modified) 10 6 Aggregate Durability Index ASTM D3744 25 7 Modified Slake Durability ASTM D4644 25 8 Aggregate Impact Value BS 812-112 25 9 Aggregate Crushing Value BS 812-112 10

Reporting and Products:

Results shall be provided to the POC via email. Also, the vendor shall make sure the raw data is properly stored and delivered to the POC.

The vendor shall take photos of testing processes and the condition of the samples before and after the tests.

General: The POC will deliver the aggregate samples to the vendor.

Delivery Required Start Date: Within one month after contract is awarded.

Required Completion Date: Six months after aggregate samples are delivered.

Total Project Time: Maximum eight months after contract is awarded.