The Latest Technologies For Concrete Pavements

Transcription

1 The Latest Technologies For Concrete Pavements 1

2 The Latest Technologies For Concrete Pavements 2 Sharper Image

3 Gizmos, Gadgets and Widgets Design Materials and Mixture Construction Tests Specifications Maintenance Are we there yet?

4 Sustainability Design MIT and others developing LCA and LCCA tools Guidance coming from FHWA

5 Design Thickness models ACPA

6 Design Thickness models ACPA

7 Overlays New Manual! Design

8 SCMs Materials and Mixture Some are reporting difficulties getting fly ash Industry reports that supply is plentiful Transportation is not EPA says fly ash non-hazardous Looking at digging up landfills ACAA

9 Materials and Mixture SCMs Ternary mixtures work! Starting to look at/for alternative materials

10 Resistance to Chemical Deicers Prescriptive Air content Maximum w/cm 0.40 to 0.42 Use SCMs How much of what? Performance Low temperature DSC Weiss

11 Materials and Mixture Interground Limestone Reduced CO 2 footprint with no reduction in performance Synergy between limestone and Class C Fly Ash can increase performance Cost Thomas

12 Durable Aggregate D-Cracking Pre-qualification using ASTM C666/C1646, Iowa pore index New methods being developed ASR resistance / mitigation AASHTO PP 65

13 Fibers Materials and Mixture Can help control crack widths Need high stiffness And enough fiber Good for thin overlays Roesler

14 TiO2 Materials and Mixture Smog eating concrete Alleman

15 Materials and Mixture Internal Curing Lightweight fine aggregate provides water for hydration Throughout the system Without affecting w/cm

16 Materials and Mixture Internal Curing Reduces shrinkage = less warping Improves permeability Can we make bigger panels in thin overlays?

17 Materials and Mixture Geotextile interlayers No stripping Simpler to install Provide drainage

18 Materials and Mixture Repair systems Aiming for low shrinkage (SRA admixtures) High bond (polymers) Low permeability (admixtures) Strong enough (and how much is that?) Rapid set?

19 Materials and Mixture Alternative dowels Fiber Stainless Coated Hollow Olson

20 Materials Curing Keep it wet, keep it warm: for durability Poly-alpha-methylstyrene is worth the premium Lithium silicate reported to reduce cracking FiberCure

21 Materials Penetrating Sealants Reduce permeability

22 Materials and Mixture WSJ Ice Free Surfaces Heat Hydrophobic (non-stick) Phase change Young

23 Materials Turn CO 2 into Nanotubes Alleman

24 Materials and Mixture Pushing the CRCP envelope 18,000-psi, 2 -thick Lots of steel and steel fibers

25 Materials and Mixture Pushing the CRCP envelope 18,000-psi, 2 -thick Lots of steel and steel fibers

26 Performance Engineered Mixtures Proportioning ACI 211 last revised in 1991 Before water reducers and SCMs Focused on structural concrete Not bad, but

27 Performance Engineered Mixtures Proportioning

28 Performance Engineered Mixtures Two aggregate gradings: Same performance with 100 pcy less cement

29 Performance Engineered Mixtures New Guide Specification Prescriptive or Performance Reporting QC Property Affected by Adequate Strength Crack free, stable F-T Durability Resistance to Chemical Deicers Durable Aggregate Impermeable Workable Cementitious type and content, w/cm Paste content Air-void system, w/cm SCM type and content, w/cm Minerology SCM type and content, w/cm Aggregate gradation, paste content

30 Construction Foundations Intelligent Compaction White

31 Construction Real Time Smoothness Allows contractor to learn and control critical activities

32 3-D Modeling Construction Pope

33 Construction Lidar Mobile Survey Records Data for modelling Bruno

34 Stringless Construction More room to work

35 Construction Construction under traffic Keep things moving vs longer schedule

36 Zero clearance Construction

37 Construction Bigger, smarter, more agile machines

38 Construction QA Saves money and heartburn Defines risk and responsibility

39 Tests Test Methods Do we know what s in there?

40 Tests Test Methods VKelly workability response to vibration

41 Tests Test Methods The Box workability response to vibration Edge slump vs honeycomb Ley

42 Tests Test Methods Calorimetry tells us about the chemistry of the system (Uniformity) Hydration Profile Sample "5P" Sample "5C" Sample "5F" Sample "5S" 9.00 J/gh :00:00 6:00:00 12:00:00 18:00:00 24:00:00 Time of Hydration (hrs)

43 Tests Test Methods Unit weight something is wrong

44 Test Methods Tests Super Air Meter (SAM) Air void system in fresh concrete Ley

45 Test Methods Tests SAM Ley

46 Test Methods Tests Ultrasonic Pulse Velocity (UPV) Setting

47 Test Methods Tests Ultrasonic Pulse Velocity (UPV) Setting and therefore sawing time

48 Tests Test Methods Maturity strength development up to 24 hours

49 Test Methods Tests Resistivity Potential Durability Formation factor Design & Control, 1929

50 Test Methods Sensors Movement Temperature Moisture Chemicals Ceylan Slowik

51 Test Methods Sensors MIT Scan-2 MIT Scan-T2

52 Test Methods Sensors MIRA GPR

53 Maintenance Recycling Black and white Into the base As concrete aggregate Process it on site Know why it failed the first time Re-use the investment already made Reduce environmental impact Reduce disposal

54 Maintenance Grinding Restore smoothness Restore friction Extend the life of the investment Make it quieter

55 Maintenance Training New Manual Workshops

56 Needs We still have Mixture ingredient measurement Shrinkage control Aggregate evaluation The ideal salt

57 Needs We Still Have Fundamental questions Does it work? How do we get it into specs? Is it worth the investment?

58 Needs We still have Education On a 5 Screen

59 Closing New toys can help us continue to make bigger, better, brighter, greener pavements