Chapter 8 full depth concrete repair
Download
1 / 76

From... Maintenance Technical - PowerPoint PPT Presentation


  • 199 Views
  • Updated On :

Chapter 8 Full Depth Concrete Repair. From… Maintenance Technical Advisory Guide (MTAG). Learning Objectives. List benefits of full-depth repairs Describe primary design considerations List available types of repair materials Describe the recommended construction procedure

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'From... Maintenance Technical' - medwin


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
Chapter 8 full depth concrete repair l.jpg

Chapter 8Full Depth Concrete Repair

From… Maintenance Technical

Advisory Guide (MTAG)


Learning objectives l.jpg
Learning Objectives

  • List benefits of full-depth repairs

  • Describe primary design considerations

  • List available types of repair materials

  • Describe the recommended construction procedure

  • List important quality control activities

  • Describe potential construction and performance problems

  • Identify troubleshooting solutions


Presentation outline l.jpg
Presentation Outline

  • Introduction

  • Design considerations

  • Construction

  • Quality control

  • Troubleshooting


Introduction l.jpg
Introduction

  • Definition

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

  • Purpose

    • Repair localized distress

    • Preparation for an overlay


Candidate distresses l.jpg
Candidate Distresses

  • 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)


Benefits l.jpg
Benefits

  • Restored rideability

  • Restored structural integrity

  • Prevents further deterioration


Limitations l.jpg
Limitations

  • Does not address structural inadequacy

  • Not a long-term solution for material-related distresses

  • Widespread deterioration

  • Cost considerations


Design materials specifications l.jpg

Module 8-1

Design, Materials & Specifications

From… Maintenance Technical

Advisory Guide (MTAG)


Presentation outline9 l.jpg
Presentation Outline

  • Introduction

  • Design considerations

  • Construction

  • Quality control

  • Troubleshooting


Design considerations l.jpg
Design Considerations

  • Selecting repair boundaries

  • Load transfer design

  • Selection of repair materials

  • Curing

  • Opening to traffic


Selecting repair boundaries extent of deterioration at joint l.jpg
Selecting Repair BoundariesExtent of Deterioration at Joint

Visual deterioration of surface

Existing

Joint

Dowel bar

Actual deterioration at bottom of slab


Selecting repair boundaries repair dimensions l.jpg
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


Selecting repair boundaries repair recommendations jpcp l.jpg

Some typical distress conditions noted with

L = low M = medium H = high

M-H

L

L

M-H

L

M

M

d

d

d

d

d

d

No repair required

Replace entire

slab-outer lane

d = 1.8 m (6 ft) minimum

Selecting Repair BoundariesRepair Recommendations (JPCP)


Selecting repair boundaries repair recommendations jrcp l.jpg

L

L

L

H

L

L

L

L

L

L

L

L

M

L

L

M

L

L

H

L

M-H

L

L

H

M

Some typical distress conditions noted with

L = low M = medium H = high

d

d

d

d

Replace entire

slab-outer lane

d

d

d = 1.8 m (6 ft) minimum

Selecting Repair BoundariesRepair Recommendations (JRCP)

No repair

required


Selecting repair boundaries multi lane considerations l.jpg
Selecting Repair BoundariesMulti-Lane Considerations

  • 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


Load transfer design recommendations l.jpg
Load Transfer DesignRecommendations

Traffic Direction

Mid-depth slab

Smooth dowels

or deformed rebars

Smooth

dowels

38 mm

(1.5 in) dia.

0.6 m

(2 ft)

3.7 m

(12 ft)

0.3 m (1 ft) typical

1.8 m (6 ft) minimum




Repair materials recommendations l.jpg
Repair MaterialsRecommendations

  • PCC mixes

  • Rapid set cement (RSC)

  • Regulated set portland cement (RSPC)

  • Proprietary materials


Curing l.jpg
Curing

  • Curing compound

  • Insulation blankets

  • HIPERPAV software


Opening to traffic l.jpg
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


Typical item codes l.jpg
Typical Item Codes

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


Construction and inspection l.jpg

Module 8-2

Construction and Inspection

From… Maintenance Technical

Advisory Guide (MTAG)


Presentation outline24 l.jpg
Presentation Outline

  • Introduction

  • Design considerations

  • Construction

  • Quality control

  • Troubleshooting


Construction procedure l.jpg
Construction Procedure

  • Concrete sawing

  • Concrete removal

  • Repair area preparation

  • Load transfer provision

  • Material placement

  • Curing

  • Joint sealing


Concrete sawing considerations l.jpg
Concrete SawingConsiderations

  • 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 sawing example sawcut l.jpg
Concrete SawingExample Sawcut


Concrete removal breakup and cleanout method l.jpg
Concrete RemovalBreakup and Cleanout Method

  • Advantages

    • Efficient breakup of concrete

    • Rapid removal of concrete onto trucks

  • Disadvantages

    • Greatly disturbs subbase

    • Potential to damage slab


Concrete removal concrete breakup l.jpg
Concrete RemovalConcrete Breakup


Concrete removal removal with a backhoe l.jpg
Concrete RemovalRemoval with a Backhoe


Concrete removal liftout method l.jpg
Concrete RemovalLiftout Method

  • Advantages

    • Does not disturb subbase

    • More rapid material removal

  • Disadvantages

    • Disposal of large concrete pieces

    • Process requires lifting pins and heavy lifting equipment


Concrete removal placement of lifting pins l.jpg
Concrete RemovalPlacement of Lifting Pins


Concrete removal lifting of slab pieces l.jpg
Concrete RemovalLifting of Slab Pieces


Concrete removal disposal of slab pieces l.jpg
Concrete RemovalDisposal of Slab Pieces



Load transfer provision drilling recommendations l.jpg
Load Transfer ProvisionDrilling Recommendations

  • 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 provision dowel bar placement l.jpg
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



Load transfer provision injecting grout or epoxy l.jpg
Load Transfer ProvisionInjecting Grout (or Epoxy)


Load transfer provision dowel bar placement41 l.jpg
Load Transfer ProvisionDowel-Bar Placement


Load transfer provision dowel bar placement42 l.jpg
Load Transfer ProvisionDowel-Bar Placement

Existing slab

Grout-retention

disk (optional)

Anchoring material

Hole dia. = d+a

Repair area

d = dowel diameter

a = 2 mm (1/8 in) for epoxy

Subbase

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

Subgrade Soil


Load transfer provision area prepared with dowels in place l.jpg
Load Transfer ProvisionArea Prepared with Dowels in Place


Material placement l.jpg
Material Placement

  • Consolidation and level finish are critical

  • Vibrate along edges of repair

  • Avoid addition of extra water

  • Texture surface to match existing pavement






Curing application of curing compound l.jpg
CuringApplication of Curing Compound


Joint sealing l.jpg
Joint Sealing

  • Saw and seal as soon as possible after placement

  • Follow the procedures described in Module 3-1




Crcp pavements candidate distresses l.jpg
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)


Crcp pavements repair recommendations l.jpg
CRCP PavementsRepair Recommendations

H

H

H

M

H

b a b

Replace as a single area

> 1.8 m

b a b

b a b

b a b

a > 1.8 m (6 ft) tied steel

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

b > 46 cm (18 in)


Crcp pavements sawcut locations l.jpg
CRCP PavementsSawcut Locations

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

A

B

A

Failure

Partial-depth cut

Full-depth cut

Partial-depth cut

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

B = 810 mm (32 in) minimum–welded; 610 mm (24 in) minimum – tied


Crcp pavements restoring continuity of reinforcing steel l.jpg
CRCP PavementsRestoring Continuity of Reinforcing Steel


Presentation outline57 l.jpg
Presentation Outline

  • Introduction

  • Design considerations

  • Construction

  • Quality control

  • Troubleshooting


Quality control l.jpg
Quality Control

  • Similar to conventional PCC paving

  • Verify repair boundaries

  • Monitor to ensure no damage to surrounding concrete

  • Project inspection

  • Proper curing techniques


Project checklist l.jpg
Project Checklist

  • Preliminary Responsibilities

    • Document Review

    • Project Review

  • Materials Checks

    • Concrete patch material

    • Load tranfer devices

    • Other materials

    • General


Project checklist60 l.jpg
Project Checklist

  • Equipment Inspections

    • Concrete Removal Equipment

    • Patch Area Cleaning Equipment

    • Testing Equipment

    • Placing and Finishing Equipment

  • Others

    • Weather Requirements

    • Traffic Control


Project checklist61 l.jpg
Project Checklist

  • Project Inspection Responsibilities

    • Concrete removal and cleanup

    • Patch preparation

    • Placing, finishing, and curing concrete

    • Resealing joints and cracks

  • Cleanup Responsibilities


Presentation outline62 l.jpg
Presentation Outline

  • Introduction

  • Design considerations

  • Construction

  • Quality control

  • Troubleshooting


Troubleshooting l.jpg

Identify

Problem

Determine

Cause

Identify

Solution

Troubleshooting

  • Construction and performance problems

  • Approach:



Selecting repair boundaries what is wrong here l.jpg
Selecting Repair BoundariesWhat is wrong here?


Selecting repair boundaries what is wrong here66 l.jpg
Selecting Repair BoundariesWhat is wrong here?


Selecting repair boundaries what is wrong here67 l.jpg
Selecting Repair BoundariesWhat is wrong here?


Troubleshooting possible performance problems l.jpg
TroubleshootingPossible Performance Problems

  • Problem:

Longitudinal cracking in the patch

  • Potential causes?


Troubleshooting possible performance problems69 l.jpg
TroubleshootingPossible Performance Problems

  • Problem:

Transverse cracking in the patch

  • Potential causes?


Troubleshooting possible performance problems70 l.jpg
TroubleshootingPossible Performance Problems

  • Problem:

Surface scaling

  • Potential causes?


Troubleshooting possible performance problems71 l.jpg
TroubleshootingPossible Performance Problems

  • Problem:

Spalling in patch at the transverse or longitudinal joint

  • Potential causes?


Troubleshooting possible performance problems72 l.jpg
TroubleshootingPossible Performance Problems

  • Problem:

Deterioration adjacent to the patch

  • Potential causes?


Troubleshooting possible performance problems73 l.jpg
TroubleshootingPossible Performance Problems

  • Problem:

Settlement of the patch

  • Potential causes?


Troubleshooting guide causes and solutions l.jpg
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


Presentation outline75 l.jpg
Presentation Outline

  • Introduction

  • Design considerations

  • Construction

  • Quality control

  • Troubleshooting


Learning objectives76 l.jpg
Learning Objectives

  • List benefits of full-depth repairs

  • Describe the primary full-depth repair design considerations

  • List available types of repair materials

  • Describe the recommended construction procedure

  • List important quality control activities

  • Describe potential construction and performance problems

  • Identify troubleshooting solutions


ad