PERFORMANCE CRITERIA

Transcription

1 NEW TEST METHODS FOR PERFORMANCE CRITERIA ANNUAL CONCRETE PAVING WORKSHOP March 9, 2017 BY: WILLY MORRISON MANAGER, CONCRETE MATERIALS LABORATORY, AMERICAN ENGINEERING TESTING 2016 American Enginee

2 OUTLINE New Testing Methods for Use in Paving AASHTO TP118 SAM Meter BOX Test Vibrating Kelly Ball Test

3 MNDOT TESTING Paving Site Visits: 20 Test Number of Tests Degree of Difficulty Observations SAM 40 (field) 100+ (lab) Medium Box Test 10 Easy VKelly 12 Easy Need trained technicians that have practiced! Takes longer than a pressure air test (3 minutes for air and for SAM 10 minutes. Bucket and digital dial must be kept clean. Must have the correct VPM vibrator. Need power or batteries. Must have the correct VPM vibrator (8000). Need power or batteries American Enginee

4 AASHTO TP118 - SAM METER

5 ACI REFERENCE The American Concrete Institute (ACI) recommends an average air content of 5 to 6% (± 1.5%) for exterior concrete with 3/4" nominal sized aggregate in moderate to severe service conditions (from ACI 201.2R-08). Additionally, ACI recommends a specific surface value of greater than 600 and a spacing factor <0.008" in order for concrete to be considered freeze thaw durable (from ACI 212.3R-10) American Enginee

6 SAM TEST RESULTS Ley

7 SAM GRAPH Ley

8 SAM GRAPH Ley

9 SAM TEST VIDEO

10 BOX TEST PAVEMENT EDGE

11 BOX TEST The Box Test A workability test for slip formed pavements. It evaluates the ability of a mixture to be consolidated and subsequently hold an edge. If the mixture does not perform well, water reducer can be added until it passes This provides a useful way to compare the performance of slip formed paving mixtures American Enginee

12 BOX TEST PAVEMENT CONCRETE The box test is a simple test that examines: Response to vibration Filling ability of the paste Ability of the slip form pavement to hold an edge cohesiveness 2016 American Enginee

13 BOX TEST VIDEO

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15 BOX TEST The slump test cannot tell us this information! Interesting fact: The origin of the word slump (1700 s) is Norwegian and originally meant to fall into a bog! 2016 American Enginee

16 VIBRATING KELLY BALL Workability test method considers the rate of movement under vibration as well as the initial yield stress.

17 OLD TEST WITH A FACELIFT The test was formerly standardized in ASTM C360-92, Standard Test Method for Ball Penetration in Freshly Mixed Hydraulic Cement Concrete (1992). However, it was discontinued in 1999 due to lack of use and never been widely used outside the United States American Enginee

18 VKELLY Concrete Pavement Mixture Design and Analysis (MDA): Development and Evaluation of Vibrating Kelly Ball Test (VKellyTest) for the Workability of Concrete Peter Taylor Iowa State University, XuhaoWang Iowa State University, i wangxh@liastate.edu t XinWang Iowa State t University, it xin@liastate.edu t 2016 American Enginee

19 VKELLY The VKelly test method appears to be suitable for assessing a mixture's response to vibration (workability). The VKelly test can report both static and dynamic characteristics while simulating the effect of vibration from paving. Multiple-operator variability for the VKelly test appears to be up to 8.3%. The VKelly test can be operated in the field, but the intended use is mostly in the laboratory to help design mixtures that perform as required. Based on the data collected to date, a VKelly Index in the range of0.8 to 1.2 in.i- Vs seems to indicate a mixture that is likely to be suitable for slipforming American Enginee

20 VIBRATING KELLY BALL VIDEO

21 QUESTIONS?