Hot-Mix Asphalt Surge Silo or Storage System Approval Procedure

Transcription

1 APPENDIX G Hot-Mix Asphalt Surge Silo or Storage System Approval Procedure This Appendix provides the Department procedures for the evaluation and approval of an HMA producer s silo/surge storage system for storage time beyond the initial 8-hour time limit. The HMA producer must contact and notify the appropriate DMM/DME to initiate this approval procedure. The collection of the required samples is to occur under the direction of the appropriate DMM/DME. The DMM/DME, or their representative, may elect to be present during collection of the required samples. The following data and samples are to be collected and submitted to the Bituminous Laboratory of the Materials and Testing Division (MTD) located at DGS Annex Complex, 81 Lab Lane, Harrisburg, PA : 1. Bituminous concrete job-mix formula should be established and be reported for the mix to be stored in the storage system. This will include gradation, percent PG-Binder content, all mix components and proportions, and all material suppliers. 2. Obtain a 1 L (1 quart) sample of PG-Binder from the sample location indicated in the QC Plan in accordance with AASHTO T 40. Immediately after filling and sealing the sample container, properly identify the sample container including the Name of the PG-Binder Supplier, Batch Number, and Tank number. 3. Obtain and submit samples of RAP, RAS or any other modifier or additive included in the mix. Contact the MTD, Bituminous Studies Materials Manager, for the proper sample quantities to be collected for each of these materials. 4. After bituminous mixture has been discharged from the HMA plant, but before it is fed into the storage system, collect samples of the mixture in duplicate (0 hour interval). 5. After bituminous mixture has been fed into the storage system, collect samples of the mixture in duplicate after 24 hour and 48 hour time intervals of storage in the storage system. Report the time of sampling and temperature of the mixture discharged from the storage system for all the specified sampling operations on Form G1. Also, report the time and temperature of the mixture feeding into the storage system (just before) at the belt discharge point. For each discharge after a specified storage period, duplicate samples are required. Completely fill two 4 L (1 gallon) metal cans with Hot-Mix Asphalt (HMA). The G - 1 Change 4

2 samples should be chilled immediately at 0 C (32 F) or lower. Place the sample in the sample can; cap the can immediately with a lid that has a pinhole in it. When the pressure build-up ceases, solder (or plug) the pinhole. Keep the sample can air-tight during delivery to the MTD. Maintain the samples at 0 C (32 F) or lower until testing is started. Sample cans should be properly identified including the time periods of storage in the storage system. G - 2 Change 4

3 SUMMARY OF REQUIRED SAMPLES AND DOCUMENTS 1. Sample of PG-Binder 1 L (1-quart) can 2. Samples of Recycled Material and/or additives. Contact Bituminous Studies 3. Samples of bituminous concrete: 0 hours storage time Two 4 L (1 gallon) cans 24 hours storage time Two 4 L (1 gallon) cans 48 hours storage time Two 4 L (1 gallon) cans TOTAL Six 4 L (1 gallon) cans 4. Copy of Job Mix Formula (TR 448 Completed, Reviewed and Signed) 5. Form G1 completed 6. Form G2 completed 7. Sample Identification Form TR-447 completed G - 3

4 FORM G1 HMA SURGE SILO/STORAGE SYSTEM EVALUATION - FIELD DATA Temperature of Mix (plant discharge) Temperature of Mix (before discharge into storage system) Time First Batch put in storage system Producer Location of Plant Type of Mix (Enclose Job-Mix Formula) Sample ID No. Age of Mix (hrs. since Mixing) Time of Discharge Temperature of discharged mix ( F) Remarks (Indicate if any problem encountered in discharge)

5 FORM G2 Details of Surge Silo/Storage Facilities 1. Location 2. Name of Manufacturer 3. Capacity (tons), diameter, height, etc. 4. Is it a batcher loaded silo or continuous loaded silo? 5. Type of Conveyer from plant to the silo; is it covered? 6. Is there any rotary distributor at the top of silo? 7. Type of heating arrangement around the silo (electric, oil) 8. If oil, what temperature is maintained? 9. If electric, is there any air gap between the elements and silo walls? 10. Atmosphere in the silo (air, Nitrogen, other inert gas)? 11. Does the silo have an inverted cone at bottom? 12. Type of door at the bottom for discharge? 13. Type of cover on the top of silo? 14. Any difficulty experienced in obtaining the mixture? 15. Source of Asphalt Cement G - 5 Change 2

6 [This page intentionally left blank.] G - 6 Change 2