1. Macro-Texture Measurements and the Performance of Chip Seals Jose Weissmann Mariano Miguel Martino

2. Objective Evaluation Criteria and Main Deliverables for Project Major distresses Flushing and Raveling Major distresses Flushing and Raveling What to measure? What to measure? How to measure? How to measure?

3. Major Tasks Develop a scanning laser based sealcoat evaluation method Develop a scanning laser based sealcoat evaluation method Develop a point laser based sealcoat evaluation method Develop a point laser based sealcoat evaluation method Develop criteria to measure sealcoat performance Develop criteria to measure sealcoat performance

4. Why are we concerned with Flushing and Raveling??

5. Macro and Micro Texture

6. Outflow Meter Circular Texture Meter (CTM) Tools to Measure Macrotexture Both ASTM Specs

7. Outflow Meter Measurement: Time for water to flow Units: seconds

8. CTM Measurement: Mean Profile Depth (MPD) Units: mm CTM Raw data

9. Macro and Micro Texture FM 1283 FM 1376

10. Data Collection

11. Factorial SH127 71 Roadway Sections

12. SH 132 between Lytle and Devine Excessive bleeding on both directions.

13. Outflow Meter Measurements SH 132 between Lytle and Devine

14. Database Contains Measurements, Photos & Location

15. Outflow Meter and CTM Correlation

16. Seal Coat Performance Cumulative Vehicles = 365 x ADT x Age

17. Failure:MPD and Crashes Rate of accidents/VMT 0.5 mm MTD

18. Failure Criteria Outflow Outflow of 14 seconds

19. Failure Criteria Performance For a road with 5,000 ADT Failure (MPD < 0.5mm) will happen at around 8 years

20. Conclusions Seal Coats that failed have an outflow reading greater than 14 sec (MPD<0.5mm) Seal Coats that failed have an outflow reading greater than 14 sec (MPD<0.5mm) The Outflow meter (inexpensive and portable) does a good job estimating MPD. The Outflow meter (inexpensive and portable) does a good job estimating MPD. New seal coats have excellent MPD and DFT readings, Outflow readings are zero. New seal coats have excellent MPD and DFT readings, Outflow readings are zero. Failure of roads with ADT of 5,000 is consistent with current TxDOT seal coat decisions. Failure of roads with ADT of 5,000 is consistent with current TxDOT seal coat decisions. Research results indicate the need to monitor traffic accurately to develop better performance curves for Seal Coats. Research results indicate the need to monitor traffic accurately to develop better performance curves for Seal Coats.

21. Obrigado!