from… maintenance technical advisory guide (mtag) chapter 8 full depth concrete repair

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From… Maintenance Technical Advisory Guide (MTAG) Chapter 8 Full Depth Concrete Repair

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Page 1: From… Maintenance Technical Advisory Guide (MTAG) Chapter 8 Full Depth Concrete Repair

From… Maintenance Technical

Advisory Guide (MTAG)

Chapter 8Full Depth Concrete Repair

Page 2: From… Maintenance Technical Advisory Guide (MTAG) Chapter 8 Full Depth Concrete Repair

Learning Objectives

1. List benefits of full-depth repairs2. Describe primary design considerations3. List available types of repair materials4. Describe the recommended construction

procedure5. List important quality control activities6. Describe potential construction and

performance problems7. Identify troubleshooting solutions

Page 3: From… Maintenance Technical Advisory Guide (MTAG) Chapter 8 Full Depth Concrete Repair

Introduction Design considerations Construction Quality control Troubleshooting

Presentation Outline

Page 4: From… Maintenance Technical Advisory Guide (MTAG) Chapter 8 Full Depth Concrete Repair

Cast-in-place concrete repairs that extend the full-depth of the existing slab

Definition

Purpose• Repair localized distress

• Preparation for an overlay

Introduction

Page 5: From… Maintenance Technical Advisory Guide (MTAG) Chapter 8 Full Depth Concrete Repair

Transverse cracking (M, H) Longitudinal cracking (M, H) Corner breaks (L, M, H) Spalling (M, H) Blowup (L, M, H) D-cracking (M, H) Deterioration of existing repairs (M, H)

Candidate Distresses

Page 6: From… Maintenance Technical Advisory Guide (MTAG) Chapter 8 Full Depth Concrete Repair

Benefits

Restored rideability Restored structural integrity Prevents further deterioration

Page 7: From… Maintenance Technical Advisory Guide (MTAG) Chapter 8 Full Depth Concrete Repair

Limitations

Does not address structural inadequacy Not a long-term solution for material-

related distresses Widespread deterioration Cost considerations

Page 8: From… Maintenance Technical Advisory Guide (MTAG) Chapter 8 Full Depth Concrete Repair

Design, Materials & Specifications

From… Maintenance Technical

Advisory Guide (MTAG)

Module 8-1

Page 9: From… Maintenance Technical Advisory Guide (MTAG) Chapter 8 Full Depth Concrete Repair

Introduction Design considerations Construction Quality control Troubleshooting

Presentation Outline

Page 10: From… Maintenance Technical Advisory Guide (MTAG) Chapter 8 Full Depth Concrete Repair

Design Considerations

Selecting repair boundaries Load transfer design Selection of repair materials Curing Opening to traffic

Page 11: From… Maintenance Technical Advisory Guide (MTAG) Chapter 8 Full Depth Concrete Repair

Actual deterioration at bottom of slab

Visual deterioration of surface

Dowel bar

ExistingJoint

Selecting Repair BoundariesExtent of Deterioration at Joint

Page 12: From… Maintenance Technical Advisory Guide (MTAG) Chapter 8 Full Depth Concrete Repair

Selecting Repair BoundariesRepair Dimensions

Minimum dimensions• Use lane-width repairs

• Length > 1.8 m (6 ft)

Long repairs (>3.7 m [12 ft] long)• Provide reinforcement, or

• Provide intermediate doweled joint

Page 13: From… Maintenance Technical Advisory Guide (MTAG) Chapter 8 Full Depth Concrete Repair

Some typical distress conditions noted withL = low M = medium H = high

M-H L L M-H L M M

No repair required

Selecting Repair BoundariesRepair Recommendations (JPCP)

d = 1.8 m (6 ft) minimum

d d dd dReplace entireslab-outer lane

d

Page 14: From… Maintenance Technical Advisory Guide (MTAG) Chapter 8 Full Depth Concrete Repair

No repair required dReplace entire

slab-outer lanedd ddd

d = 1.8 m (6 ft) minimum

LL

L

M

L

HL

HLM-H

L

H

L

L L

L L L LL

M

L

M

L

L

Some typical distress conditions noted withL = low M = medium H = high

Selecting Repair BoundariesRepair Recommendations (JRCP)

Page 15: From… Maintenance Technical Advisory Guide (MTAG) Chapter 8 Full Depth Concrete Repair

Adjacent lanes can be repaired independently• Matching joints is not essential

• Avoid small offsets

If blowups in adjacent lane• Delay until cooler weather

• Cut pressure relief joints

Selecting Repair BoundariesMulti-Lane Considerations

Page 16: From… Maintenance Technical Advisory Guide (MTAG) Chapter 8 Full Depth Concrete Repair

Smoothdowels38 mm (1.5 in) dia.

3.7 m(12 ft)

0.6 m(2 ft)

0.3 m (1 ft) typical

Smooth dowelsor deformed rebars

1.8 m (6 ft) minimum

Mid-depth slabTraffic Direction

Load Transfer DesignRecommendations

Page 17: From… Maintenance Technical Advisory Guide (MTAG) Chapter 8 Full Depth Concrete Repair

Load Transfer DesignDowel Bars

Page 18: From… Maintenance Technical Advisory Guide (MTAG) Chapter 8 Full Depth Concrete Repair

Load Transfer DesignTie Bars

Page 19: From… Maintenance Technical Advisory Guide (MTAG) Chapter 8 Full Depth Concrete Repair

PCC mixes Rapid set cement (RSC) Regulated set portland cement (RSPC) Proprietary materials

Repair MaterialsRecommendations

Page 20: From… Maintenance Technical Advisory Guide (MTAG) Chapter 8 Full Depth Concrete Repair

Curing

Curing compound Insulation blankets HIPERPAV software

Page 21: From… Maintenance Technical Advisory Guide (MTAG) Chapter 8 Full Depth Concrete Repair

Opening to Traffic

Opening criteria

• Minimum strength

• Minimum time

Typical strength

• 13.8 MPa (2,000 psi) compressive

• 2.1 MPa (300 psi) center-point

• 1.7 MPa (250 psi) third-point

Page 22: From… Maintenance Technical Advisory Guide (MTAG) Chapter 8 Full Depth Concrete Repair

Typical Item CodesItem Code Description

120090 Construction area signs

120100 Traffic control system

128650 Portable changeable message sign

150846 Remove concrete pavement

150306 Repair spalled concrete

156515 Repair spalled and unsound surface area

401108 Replace concrete pavement (rapid strength concrete

406100 Dowel bar retrofit

413101 Repair corner breaks

413111 Repair spalled joint

413114 Replace joint seal (existing concrete pavement)

413115 Seal joint (existing concrete pavement)

420201 Grind existing concrete pavement

511040 Concrete surface finish

511055 Concrete surface texture

515028 Repair spalled surface area

http://i80.dot.ca.gov/hq/esc/oe/awards/#item_code

Page 23: From… Maintenance Technical Advisory Guide (MTAG) Chapter 8 Full Depth Concrete Repair

Construction and Inspection

From… Maintenance Technical

Advisory Guide (MTAG)

Module 8-2

Page 24: From… Maintenance Technical Advisory Guide (MTAG) Chapter 8 Full Depth Concrete Repair

Introduction Design considerations Construction Quality control Troubleshooting

Presentation Outline

Page 25: From… Maintenance Technical Advisory Guide (MTAG) Chapter 8 Full Depth Concrete Repair

1. Concrete sawing

2. Concrete removal

3. Repair area preparation

4. Load transfer provision

5. Material placement

6. Curing

7. Joint sealing

Construction Procedure

Page 26: From… Maintenance Technical Advisory Guide (MTAG) Chapter 8 Full Depth Concrete Repair

Full-depth, diamond-bladed sawing Pressure relief cuts on hot days Limit traffic loading on sawed pavement

to avoid pumping If asphalt shoulder present, remove

150 mm (6 in) for form space

Concrete SawingConsiderations

Page 27: From… Maintenance Technical Advisory Guide (MTAG) Chapter 8 Full Depth Concrete Repair

Concrete SawingExample Sawcut

Page 28: From… Maintenance Technical Advisory Guide (MTAG) Chapter 8 Full Depth Concrete Repair

Advantages• Efficient breakup of concrete

• Rapid removal of concrete onto trucks

Disadvantages• Greatly disturbs subbase

• Potential to damage slab

Concrete RemovalBreakup and Cleanout Method

Page 29: From… Maintenance Technical Advisory Guide (MTAG) Chapter 8 Full Depth Concrete Repair

Concrete RemovalConcrete Breakup

Page 30: From… Maintenance Technical Advisory Guide (MTAG) Chapter 8 Full Depth Concrete Repair

Concrete RemovalRemoval with a Backhoe

Page 31: From… Maintenance Technical Advisory Guide (MTAG) Chapter 8 Full Depth Concrete Repair

Advantages• Does not disturb subbase

• More rapid material removal

Disadvantages• Disposal of large concrete pieces

• Process requires lifting pins and heavy lifting equipment

Concrete RemovalLiftout Method

Page 32: From… Maintenance Technical Advisory Guide (MTAG) Chapter 8 Full Depth Concrete Repair

Concrete RemovalPlacement of Lifting Pins

Page 33: From… Maintenance Technical Advisory Guide (MTAG) Chapter 8 Full Depth Concrete Repair

Concrete RemovalLifting of Slab Pieces

Page 34: From… Maintenance Technical Advisory Guide (MTAG) Chapter 8 Full Depth Concrete Repair

Concrete RemovalDisposal of Slab Pieces

Page 35: From… Maintenance Technical Advisory Guide (MTAG) Chapter 8 Full Depth Concrete Repair

Repair Area Preparation

Page 36: From… Maintenance Technical Advisory Guide (MTAG) Chapter 8 Full Depth Concrete Repair

Dowel holes drilled on 305 mm (12 in) centers at mid-depth

Dowel holes drilled slightly larger than dowel diameter

Smooth steel dowel bars or deformed tie bars can be used

Load Transfer ProvisionDrilling Recommendations

Page 37: From… Maintenance Technical Advisory Guide (MTAG) Chapter 8 Full Depth Concrete Repair

Load Transfer ProvisionGang Drill

Page 38: From… Maintenance Technical Advisory Guide (MTAG) Chapter 8 Full Depth Concrete Repair

Load Transfer ProvisionDowel-Bar Placement

Blow debris and dust from holes Place grout or epoxy in holes Insert dowel into hole with slight twisting

motion Install grout retention disks Grease protruding dowel ends

Page 39: From… Maintenance Technical Advisory Guide (MTAG) Chapter 8 Full Depth Concrete Repair

Load Transfer ProvisionCleaning Holes

Page 40: From… Maintenance Technical Advisory Guide (MTAG) Chapter 8 Full Depth Concrete Repair

Load Transfer ProvisionInjecting Grout (or Epoxy)

Page 41: From… Maintenance Technical Advisory Guide (MTAG) Chapter 8 Full Depth Concrete Repair

Load Transfer ProvisionDowel-Bar Placement

Page 42: From… Maintenance Technical Advisory Guide (MTAG) Chapter 8 Full Depth Concrete Repair

Subbase

Repair area

Anchoring materialGrout-retentiondisk (optional)

Hole dia. = d+a

Existing slab

a = 2 mm (1/8 in) for epoxy a = 6 mm (1/4 in) for cement grout

d = dowel diameter

Subgrade Soil

Load Transfer ProvisionDowel-Bar Placement

Page 43: From… Maintenance Technical Advisory Guide (MTAG) Chapter 8 Full Depth Concrete Repair

Load Transfer ProvisionArea Prepared with Dowels in Place

Page 44: From… Maintenance Technical Advisory Guide (MTAG) Chapter 8 Full Depth Concrete Repair

Material Placement

Consolidation and level finish are critical Vibrate along edges of repair Avoid addition of extra water Texture surface to match existing

pavement

Page 45: From… Maintenance Technical Advisory Guide (MTAG) Chapter 8 Full Depth Concrete Repair

Material Placement

Page 46: From… Maintenance Technical Advisory Guide (MTAG) Chapter 8 Full Depth Concrete Repair

Material PlacementScreeding

Page 47: From… Maintenance Technical Advisory Guide (MTAG) Chapter 8 Full Depth Concrete Repair

Material PlacementFinishing

Page 48: From… Maintenance Technical Advisory Guide (MTAG) Chapter 8 Full Depth Concrete Repair

Material PlacementTexturing

Page 49: From… Maintenance Technical Advisory Guide (MTAG) Chapter 8 Full Depth Concrete Repair

CuringApplication of Curing Compound

Page 50: From… Maintenance Technical Advisory Guide (MTAG) Chapter 8 Full Depth Concrete Repair

Saw and seal as soon as possible after placement

Follow the procedures described in Module 3-1

Joint Sealing

Page 51: From… Maintenance Technical Advisory Guide (MTAG) Chapter 8 Full Depth Concrete Repair

Construction Process Review

Page 52: From… Maintenance Technical Advisory Guide (MTAG) Chapter 8 Full Depth Concrete Repair

Special CRCP Considerations

Page 53: From… Maintenance Technical Advisory Guide (MTAG) Chapter 8 Full Depth Concrete Repair

CRCP PavementsCandidate Distresses

Punchouts (L, M, H) Deteriorated transverse cracks (M, H) Longitudinal cracking (M, H) Blowup (L, M, H) D-cracking (M, H) Deterioration of or near repair (M, H)

Page 54: From… Maintenance Technical Advisory Guide (MTAG) Chapter 8 Full Depth Concrete Repair

H H

H H Mb a b

Replace as a single area

b a bb a bb a b> 1.8 m

a > 1.8 m (6 ft) tied steel

b > 46 cm (18 in)

a > 1.2 m (4 ft) welded or mechanical connection

CRCP PavementsRepair Recommendations

Page 55: From… Maintenance Technical Advisory Guide (MTAG) Chapter 8 Full Depth Concrete Repair

1.2 m (4 ft) - welded or 1.8 m (6 ft) tied minimum

Full-depth cutPartial-depth cut

Failure

A

Partial-depth cut

CRCP PavementsSawcut Locations

A = 200 mm (8 in) minimum – welded; 610 mm (24 in) minimum – tiedB = 810 mm (32 in) minimum – welded; 610 mm (24 in) minimum – tied

B A

Page 56: From… Maintenance Technical Advisory Guide (MTAG) Chapter 8 Full Depth Concrete Repair

CRCP PavementsRestoring Continuity of Reinforcing Steel

Page 57: From… Maintenance Technical Advisory Guide (MTAG) Chapter 8 Full Depth Concrete Repair

Introduction Design considerations Construction Quality control Troubleshooting

Presentation Outline

Page 58: From… Maintenance Technical Advisory Guide (MTAG) Chapter 8 Full Depth Concrete Repair

Similar to conventional PCC paving Verify repair boundaries Monitor to ensure no damage to

surrounding concrete Project inspection Proper curing techniques

Quality Control

Page 59: From… Maintenance Technical Advisory Guide (MTAG) Chapter 8 Full Depth Concrete Repair

Project Checklist

Preliminary Responsibilities • Document Review

• Project Review Materials Checks

• Concrete patch material

• Load tranfer devices

• Other materials

• General

Page 60: From… Maintenance Technical Advisory Guide (MTAG) Chapter 8 Full Depth Concrete Repair

Project Checklist

Equipment Inspections • Concrete Removal Equipment

• Patch Area Cleaning Equipment

• Testing Equipment

• Placing and Finishing Equipment Others

• Weather Requirements

• Traffic Control

Page 61: From… Maintenance Technical Advisory Guide (MTAG) Chapter 8 Full Depth Concrete Repair

Project Checklist

Project Inspection Responsibilities

• Concrete removal and cleanup

• Patch preparation

• Placing, finishing, and curing concrete

• Resealing joints and cracks

Cleanup Responsibilities

Page 62: From… Maintenance Technical Advisory Guide (MTAG) Chapter 8 Full Depth Concrete Repair

Introduction Design considerations Construction Quality control Troubleshooting

Presentation Outline

Page 63: From… Maintenance Technical Advisory Guide (MTAG) Chapter 8 Full Depth Concrete Repair

Troubleshooting

Construction and performance problems Approach:

IdentifyProblem

DetermineCause

IdentifySolution

Page 64: From… Maintenance Technical Advisory Guide (MTAG) Chapter 8 Full Depth Concrete Repair

What is wrong here?

Page 65: From… Maintenance Technical Advisory Guide (MTAG) Chapter 8 Full Depth Concrete Repair

Selecting Repair BoundariesWhat is wrong here?

Page 66: From… Maintenance Technical Advisory Guide (MTAG) Chapter 8 Full Depth Concrete Repair

Selecting Repair BoundariesWhat is wrong here?

Page 67: From… Maintenance Technical Advisory Guide (MTAG) Chapter 8 Full Depth Concrete Repair

Selecting Repair BoundariesWhat is wrong here?

Page 68: From… Maintenance Technical Advisory Guide (MTAG) Chapter 8 Full Depth Concrete Repair

Problem:

Longitudinal cracking in the patch

Potential causes?

TroubleshootingPossible Performance Problems

Page 69: From… Maintenance Technical Advisory Guide (MTAG) Chapter 8 Full Depth Concrete Repair

Problem:

Transverse cracking in the patch

Potential causes?

TroubleshootingPossible Performance Problems

Page 70: From… Maintenance Technical Advisory Guide (MTAG) Chapter 8 Full Depth Concrete Repair

Problem:

Surface scaling

Potential causes?

TroubleshootingPossible Performance Problems

Page 71: From… Maintenance Technical Advisory Guide (MTAG) Chapter 8 Full Depth Concrete Repair

Problem:Spalling in patch at the transverse or longitudinal joint

Potential causes?

TroubleshootingPossible Performance Problems

Page 72: From… Maintenance Technical Advisory Guide (MTAG) Chapter 8 Full Depth Concrete Repair

Problem:

Deterioration adjacent to the patch

Potential causes?

TroubleshootingPossible Performance Problems

Page 73: From… Maintenance Technical Advisory Guide (MTAG) Chapter 8 Full Depth Concrete Repair

Problem:

Settlement of the patch Potential causes?

TroubleshootingPossible Performance Problems

Page 74: From… Maintenance Technical Advisory Guide (MTAG) Chapter 8 Full Depth Concrete Repair

Troubleshooting Guide – Causes and Solutions

Undercut spalling Saw binds Adjacent slab damage Slab disintegration Patch filled with water Grout flow out of dowel holes Misaligned dowels

Page 75: From… Maintenance Technical Advisory Guide (MTAG) Chapter 8 Full Depth Concrete Repair

Introduction Design considerations Construction Quality control Troubleshooting

Presentation Outline

Page 76: From… Maintenance Technical Advisory Guide (MTAG) Chapter 8 Full Depth Concrete Repair

Learning Objectives

1. List benefits of full-depth repairs2. Describe the primary full-depth repair design

considerations3. List available types of repair materials4. Describe the recommended construction

procedure5. List important quality control activities6. Describe potential construction and

performance problems7. Identify troubleshooting solutions