Guidebook for Road Construction and Maintenance Management

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IMPROVEMENT OF QUALITY MANAGEMENT FOR

HIGHWAY AND BRIDGE CONSTRUCTION AND

MAINTENANCE, PHASE II

GUIDEBOOK FOR

ROAD CONSTRUCTION AND

MAINTENANCE MANAGEMENT

2014

Department of Public Works and Highways


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IMPROVEMENT OF QUALITY MANAGEMENT FORHIGHWAY AND BRIDGE CONSTRUCTION AND

MAINTENANCE, PHASE II

GUIDEBOOK FOR ROAD CONSTRUCTION

AND MAINTENANCE MANAGEMENT

SECOND EDITION

SEPTEMBER 2014

DEPARTMENT OF PUBLIC WORKS AND HIGHWAYS

JAPAN INTERNATIONAL COOPERATION AGENCY


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Republic of the Philippines

DEPARTMENT OF PUBLIC WORKS AND HIGHWAYS

OFFICE OF THE SECRETARY

Manila


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Guidebook for Road Construction and Maintenance Management ii

TABLE OF CONTENTS

FOREWORD……………………………………………………………………… i

TABLE OF CONTENTS .................................................................................. ii

LIST OF TABLES ........................................................................................... vi

LIST OF FIGURES ......................................................................................... vii

ACKNOWLEDGMENT ................................................................................... xii

ACRONYMS ................................................................................................. xiii

Chapter 1 INTRODUCTION ....................................................................... 1- 11.1 Background .................................................................................................. 1- 1

1.2 Purpose ........................................................................................................ 1- 2

Chapter 2 SOIL CLASSIFICATION AND MODULUS .................................. 2- 1

2.1 Unified Soil Classification ............................................................................. 2- 1

2.2 Reference Data for Soil Classification .......................................................... 2- 2

2.3 Estimated Soil Modulus by N-value .............................................................. 2- 4

Chapter 3 ROAD DRAINAGE .................................................................... 3- 1

3.1 Design of Drainage ..................................................................................... 3- 1

3.1.1 Estimating Discharge .............................................................................. 3- 1

3.1.2 Capacity of Drainage .............................................................................. 3- 4

3.1.3 Specific Discharge Curve ........................................................................ 3- 5

3.2 Cross Drainage ............................................................................................ 3- 7

3.2.1 Installation of Cross Drainage ................................................................. 3- 7

3.2.2 Headwalls ............................................................................................... 3- 7

3.3 Underground Drainage ................................................................................. 3- 8

3.3.1 Function of Underground Drainage ......................................................... 3- 8

3.3.2 Typical Cross Section of Underground Drainage System ....................... 3- 9

3.3.3 Treatment of Seepage from Mountainous Slope .................................... 3- 9

3.3.4 Underground Drainage on Cut and Embankment Portions .................... 3-10

Chapter 4 PAVEMENT ............................................................................... 4- 1

4.1 Types of Pavement....................................................................................... 4- 1


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iii Guidebook for Road Construction and Maintenance Management

4.1.1 Rigid Pavement ....................................................................................... 4- 1

4.1.2 Flexible Pavement .................................................................................. 4- 2

4.2 Portland Cement Concrete Pavement .......................................................... 4- 2

4.2.1 Quality Control ........................................................................................ 4- 2

4.2.2 Design Mix and Trial Paving.................................................................... 4- 2

4.2.3 Admixture/Additive .................................................................................. 4- 3

4.2.4 Concrete Paving Activities ....................................................................... 4- 3

4.2.5 Types of Formworks ................................................................................ 4- 4

4.2.6 Weakened Plane Joint ............................................................................ 4- 4

4.2.7 Replacement of Deteriorated PCC Slabs ................................................ 4- 6

4.2.8 PCCP Widening ...................................................................................... 4- 7

4.2.9 Temperature Control ............................................................................... 4- 7

4.2.10 Surface Texturing .................................................................................... 4- 8

4.2.11 Subbase .................................................................................................. 4- 8

4.2.13 Asphalt Concrete Overlay on PCCP ....................................................... 4- 8

4.3 Introduction of Newly Approved Pavement Materials ................................... 4- 9

4.3.1 Instapave ................................................................................................ 4- 9

4.3.2 Pavement Dressing Conditioner ............................................................. 4- 9

4.3.3 Polymer Modified Bitumen ...................................................................... 4-10

4.3.4 Stone Mastic Asphalt .............................................................................. 4-10

Chapter 5 SLOPE PROTECTION WORKS ................................................ 5- 1

5.1 Appropriate Slope ......................................................................................... 5- 1

5.1.1 Cut Slope ................................................................................................ 5- 1

5.1.2 Embankment Slope ................................................................................. 5- 3

5.2 Slope Failure ................................................................................................ 5- 4

5.2.1 Soil Slope Collapse ................................................................................. 5- 4

5.2.2 Rock Slope Collapse ............................................................................... 5- 5

5.2.3 Landslide ................................................................................................. 5- 6

5.2.4 Road Slip ................................................................................................ 5- 7

5.2.5 Debris Flow ............................................................................................. 5- 9

5.3 Slope Failure Countermeasures ................................................................... 5-10

5.3.1 Soil Slope Failure Countermeasures ...................................................... 5-10

5.3.2 Rock Slope Failure Countermeasures .................................................... 5-11


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Guidebook for Road Construction and Maintenance Management iv

5.4 Slope Erosion Control .................................................................................. 5-11

5.4.1 Slope Drainage ....................................................................................... 5-12

5.4.2 Vegetation Works .................................................................................... 5-13

5.4.3 Coconet Bio-engineering ........................................................................ 5-16

5.5 Slope Protection Structures .......................................................................... 5-21

5.5.1 Retaining Walls ....................................................................................... 5-22

5.5.2 Grouted Riprap ....................................................................................... 5-23

5.5.3 Cribwall ................................................................................................... 5-24

5.5.4 Gabion Wall ............................................................................................ 5-26

5.5.5 Mechanically Stabilized Embankment Wall (MSE Wall) .......................... 5-27

5.6 Rock Slope Protection .................................................................................. 5-285.6.1 Cutting and Removal .............................................................................. 5-28

5.6.2 Shotcrete ................................................................................................ 5-28

5.6.3 Rocknet ................................................................................................... 5-29

5.6.4 Rock Catcher .......................................................................................... 5-30

5.6.5 Rock Shed .............................................................................................. 5-30

5.7 Countermeasures for Landslide ................................................................... 5-30

5.8 Provision of Underground Drainage Pipe thru Boring .................................. 5-30

5.9 Slope Stability Analysis ................................................................................ 5-32

Chapter 6 RIVER AND COASTAL EROSIONS .......................................... 6-1

6.1 River Erosion ................................................................................................ 6- 1

6.1.1 Examples of Road Damages caused by River Erosion .......................... 6- 2

6.1.2 Countermeasures for River Erosion ........................................................ 6- 2

6.2 Coastal Erosion ............................................................................................ 6-13

6.2.1 Case 1: Scouring of Foundation ............................................................. 6-13

6.2.2 Case 2: Washout of Backfill Materials ..................................................... 6-15

6.2.3 Case 3: Collapse of Mainbody ................................................................ 6-17

6.2.4 Countermeasures for Coastal Erosion .................................................... 6-18

Chapter 7 ROAD SAFETY ......................................................................... 7- 1

7.1 Road Signs ................................................................................................... 7- 1

7.1.1 Classifications ......................................................................................... 7- 1

7.1.2 Standard Application ............................................................................... 7- 3


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7.1.3 Design ..................................................................................................... 7- 4

7.2 Weighbridge Station ..................................................................................... 7- 4

7.3 Road Warning System .................................................................................. 7- 6

Chapter 8 MONITORING AND INVESTIGATION ........................................ 8- 1

8.1 Weather Monitoring ...................................................................................... 8- 1

8.1.1 Rain Gauges ........................................................................................... 8- 1

8.1.2 Weather Station ...................................................................................... 8- 2

8.2 Visual Inspection of Pavement ..................................................................... 8- 2

8.2.1 ROCOND ................................................................................................ 8- 2

8.2.2 Portable Falling Weight Deflectometer (FWD) ........................................ 8- 2

8.3 Slope Investigation ....................................................................................... 8- 8

8.3.1 Measurement .......................................................................................... 8- 8

8.3.2 Visual Slope Investigation ....................................................................... 8- 9

8.3.3 Digital Clinometer .................................................................................... 8-11

8.4 Slope Monitoring .......................................................................................... 8-16

8.4.1 Crack Monitoring ..................................................................................... 8-16

8.4.2 Wire Extension Meter .............................................................................. 8-16

8.5 Soil Investigations......................................................................................... 8-17

8.5.1 Boring and Core Sampling ...................................................................... 8-17

8.5.2 Sounding for Soil Strength Test ............................................................... 8-18

8.6 Ground Water Survey and Monitoring .......................................................... 8-21

8.6.1 Ground Water Logging ............................................................................ 8-21

8.6.2 Hand Held Water Quality Sensor ............................................................ 8-23

8.7 Strain Gauge with PVC Pipe ........................................................................ 8-24

8.7.1 Summary of Pipe Strain Gauge .............................................................. 8-24

8.7.2 Checklist for Installation of Pipe Strain Gauge ........................................ 8-24

8.7.3 Strain Gauges Monitoring ....................................................................... 8-24

8.7.4 Digital Strain Meter.................................................................................. 8-27


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vii Guidebook for Road Construction and Maintenance Management

LIST OF FIGURES

Figure 3.1 Rainfall Intensity Duration Frequency (RIDF) Curves Source:

328 Baguio Synoptic Station.............................................................. 3- 3Figure 3.2 Rainfall Intensity Duration Frequency (RIDF) Curves Source:

646 Mactan Synoptic Station ............................................................. 3- 3

Figure 3.3 Hydraulic Radius Formula ................................................................. 3- 5

Figure 3.4 Specific Discharge Curve (Luzon) ..................................................... 3- 6

Figure 3.5 Specific Discharge Curve (Visayas) .................................................. 3- 6

Figure 3.6 Specific Discharge Curve (Mindanao) ............................................... 3- 6

Figure 3.7 Typical Inlet and Outlet Headwalls ..................................................... 3- 7

Figure 3.8 Structure of Headwall ........................................................................ 3- 8

Figure 3.9 Relation of Water Content and CBR .................................................. 3- 8

Figure 3.10 Typical Underground Drainage for a 2-lane Road ............................. 3- 9

Figure 3.11 Typical Underground Drainage for a 4-lane Road ............................. 3- 9

Figure 3.12 Typical Underground Road Drainage for Mountainous Terrain .......... 3- 9

Figure 3.13 Treatment of Seepage from Mountainous Slope ............................... 3- 10

Figure 3.14 Underground Drainages on Cut and Embankment Sections ............. 3- 10

Figure 4.1 Conceptual Figure Showing Load Distribution

for Rigid and Flexible Pavements ...................................................... 4- 1

Figure 4.2 Flowchart for Preparatory Work for Concrete Paving ........................ 4- 2

Figure 4.3 Concrete Paving Activities ................................................................. 4- 3

Figure 4.4 Paving Works .................................................................................... 4- 4

Figure 4.5 PCCP Joints and Load Transfer Device ............................................ 4- 5

Figure 4.6 Deteriorated PCCP ............................................................................ 4- 6

Figure 4.7 PCCP Widening ................................................................................. 4- 7

Figure 4.8 PCCP Widening Work ....................................................................... 4- 7

Figure 4.9 Thermometer ..................................................................................... 4- 7

Figure 4.10 Texturing of the Surface ..................................................................... 4- 8Figure 4.11 Laying of Base Materials by Means of Road Grader and Paver ........ 4- 8

Figure 5.1 Geology and Slope Gradient ............................................................. 5- 3

Figure 5.2 Typical Soil Slope Collapse ............................................................... 5- 5

Figure 5.3 Typical Rock Slope Collapse ............................................................. 5- 5

Figure 5.4 Typical Landslide ............................................................................... 5- 6

Figure 5.5 Road Slip ........................................................................................... 5- 7

Figure 5.6 Typical Road Slip ............................................................................... 5- 7

Figure 5.7 Stages of Road Slip ........................................................................... 5- 7


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Guidebook for Road Construction and Maintenance Management viii

Figure 5.8 Landslide Caused by Water Infiltration from Road ............................ 5- 8

Figure 5.9 Road Slip due to Slope Erosion ......................................................... 5- 8

Figure 5.10 Surface Flow Concentrations ............................................................ 5- 9

Figure 5.11 Road Slip caused by Leakage from Pipe Culvert .............................. 5- 9Figure 5.12 Typical Debris Flow ........................................................................... 5-10

Figure 5.13 Selections of Soil Slope Failure Countermeasures ........................... 5-10

Figure 5.14 Selections of Rock Slope Failure Countermeasures ......................... 5-11

Figure 5.15 Relation between Slope and Rainfall ................................................. 5-11

Figure 5.16 Erosion on Cut Slope......................................................................... 5-12

Figure 5.17 Relations between Content Ratio of Fines

and Natural Water Content ................................................................ 5-12

Figure 5.18 Surface Water Overtopping Slope Drainage ..................................... 5-13

Figure 5.19 Inappropriate Vegetation Work .......................................................... 5-14

Figure 5.20 Wicker Works as Vegetation Base .................................................... 5-14

Figure 5.21 Vetiver Grass ..................................................................................... 5-15

Figure 5.22 Sketch of slope to be protected with Vetiver Grass ........................... 5-15

Figure 5.23 Coconet (CGN 700) ........................................................................... 5-17

Figure 5.24 Cocolog/Fascine (CGR 200) ............................................................. 5-17

Figure 5.25 Stakes ............................................................................................... 5-17

Figure 5.26 Coco Coir Peat .................................................................................. 5-18

Figure 5.27 Ropes ................................................................................................ 5-18

Figure 5.28 Typical Cross Sections for Bio-Engineering Works ........................... 5-19

Figure 5.29 Site Preparation ................................................................................. 5-20

Figure 5.30 Laying of Nets.................................................................................... 5-20

Figure 5.31 Anchoring .......................................................................................... 5-21

Figure 5.32 Sewing ............................................................................................... 5-21

Figure 5.33 Hydroseeding .................................................................................... 5-21

Figure 5.34 Gravity Type (Rock Catcher Retaining Wall) ..................................... 5-22

Figure 5.35 Leaning Type Retaining Wall ............................................................. 5-22Figure 5.36 Construction steps for Stone Masonry .............................................. 5-23

Figure 5.37 Construction steps for Grouted Riprap .............................................. 5-23

Figure 5.38 Grouted Riprap .................................................................................. 5-24

Figure 5.39 Stone Masonry Cribwall ..................................................................... 5-25

Figure 5.40 Reinforced Concrete Crib and Pitching Wall ..................................... 5-25

Figure 5.41 Reinforced Concrete Frame with Vegetation Works .......................... 5-26

Figure 5.42 Gabion Wall ....................................................................................... 5-26

Figure 5.43 Constructed Gabion Wall at a Location with Seepage ...................... 5-27


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Figure 5.44 Mechanically Stabilized Embankment by means of Geotextile fabrics 5-27

Figure 5.45 Mechanically Stabilized Embankment Wall (Terree Armee Wall) ....... 5-27

Figure 5.46 Relation between Rock Slope Height and Height of Bounce of Stone 5-28

Figure 5.47 Cutting and Removal of Unstable Rock Slope ................................... 5-28Figure 5.48 Shotcrete ........................................................................................... 5-29

Figure 5.49 Rocknet ............................................................................................. 5-29

Figure 5.50 Rock Catcher ..................................................................................... 5-30

Figure 5.51 Rock Shed ......................................................................................... 5-30

Figure 5.52 Rainfall and Groundwater Level ........................................................ 5-31

Figure 5.53 Typical Underground Drainage Pipe Installations .............................. 5-31

Figure 5.52 Fellenius Method ............................................................................... 5-32

Figure 6.1 Degradation due to Riverbed Erosion ................................................ 6- 1

Figure 6.2 Riverbank Erosion at Bend ................................................................ 6- 2

Figure 6.3 Riverbank Erosion caused by Overflow ............................................. 6- 2

Figure 6.4 Riverbed Erosion ............................................................................... 6- 2

Figure 6.5 Selection of River Erosion Countermeasures Flowchart ................... 6- 3

Figure 6.6 Types of Revetment Works ................................................................ 6- 4

Figure 6.7 Design Procedure for River Revetment Work .................................... 6- 5

Figure 6.8 Typical Cross Section of Revetment Works ....................................... 6- 5

Figure 6.9 Laying of Concrete Blocks on River Slope ........................................ 6- 6

Figure 6.10 Sample Arrangement of Groundsills .................................................. 6- 7

Figure 6.11 Typical section of Groundsill .............................................................. 6- 7

Figure 6.12 Design Procedure for Groundsill ........................................................ 6- 8

Figure 6.13 Arrangement of Groundsills Relative to the Direction of Flow ........... 6- 9

Figure 6.14 Details of Groundsill ........................................................................... 6- 9

Figure 6.15 Typical Section of Groundsill ............................................................. 6-10

Figure 6.16 Rechanneling Concept for Riverbank and Riverbed Protections ....... 6-11

Figure 6.17 Type of Spur Dike .............................................................................. 6-11

Figure 6.18 Typical Cross Sections of Spur Dike .................................................. 6-12Figure 6.19 Examples of Road Damages caused by Coastal Erosion ................. 6-13

Figure 6.20 Collapse of Coastal Revetment due to Scouring of Foundation Bed . 6-14

Figure 6.21 Conceptual Diagram of Scouring of Foundation Bed ........................ 6-14

Figure 6.22 Collapse of Coastal Revetment ......................................................... 6-15

Figure 6.23 Collapse of Coastal Revetment due to Washout of Backfill Materials 6-16

Figure 6.24 Washout of Backfill Material............................................................... 6-16

Figure 6.25 Collapse of Coastal Revetment due to Washed out Backfill Material 6-16

Figure 6.26 Collapse of Coastal Revetment due to Overtopping .......................... 6-17


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Figure 6.27 Levels of Erosion of Grouted Riprap Surface .................................... 6-17

Figure 6.28 Collapsed Revetment due to Progression of Cracks ......................... 6-18

Figure 6.29 Conceptual Design of Coastal Slope Revetment .............................. 6-19

Figure 6.30 Selection of Countermeasures against Coastal Erosion ................... 6-20Figure 6.31 Typical Foundation Water Cut-off Wall .............................................. 6-21

Figure 6.32 Considerations for Coastal Revetment Design .................................. 6-22

Figure 7.1 Regulatory Signs (Type R) ................................................................ 7- 2

Figure 7.2 Warning Signs (Type W) .................................................................... 7- 2

Figure 7.3 Guide or Informative Signs (Type G) ................................................. 7- 2

Figure 7.4 Instructional Signs (Type S) ............................................................... 7- 3

Figure 7.5 Hazard Markers (Type HM) ............................................................... 7- 3

Figure 7.6 Weighbridge Stations ........................................................................ 7- 4

Figure 7.7 Road Status and Information System ................................................ 7- 6

Figure 8.1 Manual Data Collection from a Standard Rain Gauge....................... 8- 1

Figure 8.2 Standard Rain Gauge ........................................................................ 8- 1

Figure 8.3 Weighing Precipitation Rain Gauge ................................................... 8- 1

Figure 8.4 Weather Station ................................................................................. 8- 2

Figure 8.5 Setting up of FWD ............................................................................. 8- 3

Figure 8.6 The Drop Rig ..................................................................................... 8- 3

Figure 8.7 The Mainbody and Display Instrument .............................................. 8- 3

Figure 8.8 Measure Display of Portable FWD .................................................... 8- 4

Figure 8.9 Estimated Engineering Property ........................................................ 8- 6

Figure 8.10 Example of Analysis Sheet for Portable FWD ................................... 8- 7

Figure 8.11 Rough Determination of Slope Height and Angle .............................. 8- 8

Figure 8.12 Road Slope Survey by Digital Distance Meter ................................... 8- 8

Figure 8.13 Digital Distance Meter ....................................................................... 8- 8

Figure 8.14 Visual Slope Investigation (1/2) ......................................................... 8- 9

Figure 8.15 Visual Slope Investigation (2/2) ......................................................... 8- 9

Figure 8.16 Block Diagram of Complex Earth Slide/Earth Flow ........................... 8-10Figure 8.17 Typical Configuration and Phenomena of Earth Slide ....................... 8-10

Figure 8.18 Important Locations for Slope Investigation on Cut Slope ................. 8-10

Figure 8.19 Strike and Dig .................................................................................... 8-11

Figure 8.20 Clinometer ......................................................................................... 8-11

Figure 8.21 Parts of Digital Clinometer ................................................................. 8-12

Figure 8.22 Usage of Digital Clinometer ............................................................... 8-12

Figure 8.23 Crack Displacement Measurement ................................................... 8-16

Figure 8.24 Wire Extension Meter ........................................................................ 8-16


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Figure 8.25 Sample Core Boring at Landslide Portion .......................................... 8-17

Figure 8.26 Sample Core Boring at Soft Rock Slide ............................................. 8-17

Figure 8.28 Schematic Diagram of Standard Penetration Test ............................. 8-18

Figure 8.29 Dynamic Cone Penetrometer (Dual Mass Type) ............................... 8-18Figure 8.30 Operation of DCP .............................................................................. 8-19

Figure 8.31 Simplified Dynamic Cone Penetrometer ............................................ 8-19

Figure 8.32 Friction Loss on Simplified Dynamic Cone Penetrometer Test .......... 8-20

Figure 8.33 Simplified Dynamic Cone Penetrometer (Sample Output) ................ 8-21

Figure 8.34 Schematic Diagram of Groundwater Logging .................................... 8-22

Figure 8.35 Sample Graph of Groundwater Logging ............................................ 8-22

Figure 8.36 Pipe Strain Gauge ............................................................................. 8-24

Figure 8.37 Sample Pipe Strain Gauge Monitoring .............................................. 8-25

Figure 8.38 Monitoring of Pipe Strain Gauge (Sample Output) ............................ 8-26

Figure 8.40 Monitoring of Pipe Strain Gauge (Sample Profile) ............................. 8-27

Figure 8.42 Connection with Half Bridge Type ...................................................... 8-29

Figure 8.41 Strain Gauges with PVC Pipe ............................................................ 8-29


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Guidebook for Road Construction and Maintenance Management xii

ACKNOWLEDGEMENT

In behalf of the CWG on Road Manuals Improvement, the Group Leader acknowledges the

TWG members and the regional project managers of pilot regions for their patience,

guidance, words of encouragement and useful critiques which really helped us a lot in

accomplishing this undertaking.

TWG Members:

Dr. Judy F. SESE, Chairperson, OIC-Director, Bureau of Research and Standards

Ms. Carolina S. CANUEL, Fmr. Vice Chairperson, Fmr. Div. Chief, DPD, P/S

Mr. Adriano M. DOROY, Asst. Director, Bureau of Design

Mr. Aristarco M. DOROY, OIC-Asst. Director, Bureau of Construction

Ms. Edna F. MEÑEZ, OIC-DE, Negros Occidental 4th DEO, DPWH-Region VII

Mr. Felipe S. RAMOS, Fmr. Chief, Technical Services and Evaluation Div., BRS

Mr. Nestor B. CAOILE, OIC-Division Chief, Materials Testing Division, BRS

Regional Project Managers:

Ms. Elsa T. NABOYE, Regional Project Manager, Asst. Chief, QAD, DPWH-CAR

Ms. Ramie B. DOROY, Regional Project Manager, DE, Negros Oriental 1st DEO,

DPWH-Region VII

Ms. Rowena P. JAMITO, Regional Project Manager, Engr. V, MD, RO-XI

Thank you also to CWG Members for their efforts and collaborations.

CWG Members:

Mr. Jay Jenner R. BIARES, Engr. III, CAR ; Group Leader

Mr. Elmer R. FIGUEROA, Engr. III, BOC

Mr. Ernante S. ANTONIO, Engr. III, BOM

Ms. Carina B. DIAZ, Engr. III, BOD

Ms. Nenita R. VALENCIA, Former Engr. III, BRS

Mr. Vicente R. VALLE, JR., Engr. IV, DPWH-Region VIIMs. Aurora M. LACASANDILE, Engr. III, CD, DPWH-Region XI

Finally, we wish to thank our Expert, Mr. Ryoichi Yamasaki, Co-Team Leader, JICA TCP II

and his Asst. Engineer, Mr. Feliciano P. Carpio, for their support and encouragement

throughout this activity.


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ACRONYMS

A

AASHTO American Association of State Highway and Transportation Official

AC Asphalt Concrete

ACP Asphalt Concrete Pavement

ASTM American Society for Testing and Materials

B

BOC Bureau of Construction

BOD Bureau of Design

BOE Bureau of Equipment

BOM Bureau of Maintenance

BRS Bureau of Research and Standards

BST Bituminous Surface Treatment

C

CAR Cordillera Administrative Region

CBR California Bearing Ratio

CSB Cold Seal Bitumen

CWG Counterpart Working Group

D

DCP Dynamic Cone Penetrometer

DE District Engineer

DENR Department of Environment and Natural Resources

DEO District Engineering Office

DO Department OrderDPWH Department of Public Works and Highways

F

FCSEC Flood Control and Sabo Engineering Center

FWD Falling Weight Deflectometer


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Guidebook for Road Construction and Maintenance Management xiv

G

GIS Geographical Information System

GOJ Government of JapanGOP Government of the Philippines

GPS Global Positioning System

GVW Gross Vehicle Weight

H

HDM-4 Highway Development and Management Version 4

HE Highway Engineer

I

IRI International Roughness Index

J

JICA Japan International Cooperation Agency

JCC Joint Coordinating Committee

L

LAAV Los Angeles Abrasion Value

M

ME Materials Engineer

MO Memorandum Order

MSE Mechanically Stabilized Embankment

N

NEDA National Economic and Development Authority

P

PAGASA Philippine Atmospheric, Geophysical and Astronomical Services Administration

PCC Portland Cement Concrete

PCCP Portland Cement Concrete Pavement

PDC Pavement Dressing Conditioner

PMB Polymer Modified Bitumen

PMS Pavement Management System


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xv Guidebook for Road Construction and Maintenance Management

PS Planning Service

Q

QA Quality Assurance

QC Quality Control

R

RCBC Reinforced Concrete Box Culvert

RCP Reinforced Concrete Pipe

RCPC Reinforced Concrete Pipe Culvert

RIDF Rainfall Intensity Duration Frequency

RMMS Routine Maintenance Management System

RO Regional Office

ROCOND Visual Road Condition Rating System

ROW Right-of-Way

RS Road Safety

S

SDCP Simplified Dynamic Cone Penetrometer

SMA Stone Mastic Asphalt

SPT Standard Penetration Test

T

TARAS Traffic Accident Recording and Analysis System

TCP Technical Cooperation Project

TOR Terms of Reference

TWG Technical Working Group

V

VCI Visual Condition Index


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Chapter 1 Introduction

1.1 Background

The Department of Public Works and Highways, hereinafter referred to as DPWH and

Japan International Cooperation Agency, hereinafter referred to as JICA, agreed in 2006 to

implement the project for Improvement of Quality Management for Highway and Bridge

Construction and Maintenance, hereinafter called as " Phase I", aiming to enhance the

engineering knowledge of the engineers of DPWH.

For implementation of the said project, the DPWH organized the Joint Coordinating

Committee, hereinafter called as JCC, Technical Working Group, hereinafter called as TWG

and Counterpart Working group, hereinafter called as CWG and the JICA dispatched the JICA

Technical Cooperation Project Team, hereinafter referred to as "JICA TCP Team" from

February 2007 to February 2010.

Under Phase I, the following manuals/guidelines were prepared and issued for road

construction and maintenance through the CWG's activities.

* Guidebook for Road Construction and Maintenance Management in the Republic of

the Philippines,

* Road Project Management and Supervision Manual, Volume I: Main Text and * Road Project Management and Supervision Manual, Volume II: Appendices (Standard

Forms, Examples and References)

From October 2011 to September 2014, the DPWH and JICA TCP Team -newly

dispatched by JICA - implemented the project for Improvement of Quality Management for

Highway and Bridge Construction and Maintenance, Phase II, hereinafter called as Phase II to

aim further enhancement.

This manual, Guidebook for Road Construction and Maintenance was prepared under

Phase II through the revision work done by CWG based on the Guidebook mentioned above.

The Guidebook was made through consolidations of seminars and On-the-Job-Training

materials, texts, presentations and is mainly focused on the engineering knowledge necessary

for road and slope management.

Guidebook for Road Construction and Maintenance Management 1 - 1


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1.2 Purpose

Engineers of the DPWH concerned with road and slope construction and maintenance

are the main targets of this Manual. The CWG made efforts to make this Reference easy tounderstand by the young Engineers, especially beginners, hence, it would be an effective tool

related to the above areas.

1 - 2 Guidebook for Road Construction and Maintenance Management


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Chapter 2 Soil Classification and

Modulus

2.1 Unified Soil Classification

Table 2.1 and 2.2 show the Soil Classification utilized for field identification.

Table 2.1 Unified Soil Classification System (Sands and Gravels)

Group

SymbolsTypical Names

C o

a r s e g r a i n e d s o i l s

M o r e t h a n h a l f o f m a t e r i a l i s b i g g e r t h a n n o . 2 0 0 s i e v e s i z e

G r a v e l s

M o r e t h a n h a l f o f c o a r s e

F r a c t i o n i s s m a l l e r t h a n n o . 4 s i e v e s i z e

C l e a n g r a v e l

( l i t t l e o r f i n e s )

Wide range in grain size

and substantial amount ofall intermediate particle

size

GWWell graded gravels,gravel-sand mixtures

little or no fines

Predominantly one size or

a range of sizes with some

intermediate sizes missing

GP

Poorly graded gravels,

gravel-sand mixtures

little or no fines

G r a v e l w i t h f i n e s

( a p p l i c a b l e

a m o u n t o f f i n e )

Non-plastic fines (for

identification procedures,

See ML)

GM

Silty gravels, poorly

graded grave-sand silt

mixtures

Plastic fines (for

identification, See CL)GC

Clayey gravels,

poorly graded-sand

clay mixtures

S a n d s

M o r e t h a n h a l f o f c o a r s e f r a c t i o n i s s m a l l e r

t h a

n n o . 4 s i e v e s i z e

( f o

r v i s u a l c l a s s i f i c a t i o n , t h e 1 / 4 " s i z e m a y

b e

u s e d a s e q u i v a l e n t t o t h e n o . 4 s i e v e s i z e )

C l e a n s a n d

( l i t t l e o r f i n e s )

Wide range in grain sizeand substantial amount of

all intermediate particle

size

SW

Well graded sands,

gravelly sands, little

or no fines

Predominantly one size or

range of range of sizes with

some intermediate sizes

missing

SP

Poorly graded sands,

gravelly sands, little

or no fines

S a n d w i t h f i n e s

( a p p l i c a b l e

a m

o u n t o f f i n e ) Non-plastic fines (for

identification, See ML)SM

Silty sand, poorly

graded sand-silt

mixtures

Non-plastic fines (for

identification, See CL) SC

Clayey sands, poorly

graded sand-claymixtures



24/138

Table 2.2 Unified Soil Classifications (Silts, Clays and Organic Soils)

Dry strength

(Crushingcharacteristics)

Dilitancy

(Reaction toshaking)

Toughness

(Consisten

cy near plastic

limit)

Group

Symbols Typical Names

F i

n e g r a i d e d s o i l s

M

o r e t h a n h a l f o f m a t e r i a l i s s m a l l e r t h a n n o

. 2 0 0 s i e v e s i z e

S i l t s a n d c l a y s

L i q u i d l i m

i t l e s s t h a n 5 0

None to slightQuick to

slow None ML

Inorganic silts and

very fine sands, rock

flour, silty or clayey

fine sands with slight

plasticity

Medium to

high

None to

very slowMedium CL

Inorganic clays of

low to medium

plasticity gravelly

clays, sandy clays,

silty-clays, lean clays

Slight to

MidiumSlow Slight OL

Organic silts and

organic silt-clays of

low plasticity

S i

l t s a n d c l a y s

L i q u i d l i m i t g r e a t e r t h a n 5 0

Slight to

medium

Slow to

none

Slight to

MediumMH

Inorganic silts,

micaceous or

diatomaceous fine

sandy or silty soils,

elastic silts

High to very

high

None to

very slowHigh CH

Inorganic clay of high

plasticity < fat clays

Medium to

high

None to

very slow

Slight to

MediumOH

Organic clays of

medium to high

plasticity

Highly organic soilReadily identified by color, odor, spongy feel

and frequently fibrous textureP+

Peat and other highly

organic soils

2.2 Reference Data for Soil Classification

In DPWH, there is no available reference data for soil classification for use in

preliminary design. Table 2.3 shows a reference data for preliminary design of Japan

Expressway for DPWH Engineer's references.



25/138

Table 2.3 Soil Classification Reference Data for Preliminary Design

Soil Type ConditionUnit weight

(kN/m3)

Internal

friction angle

(degree)

Cohesion

(kN/m3)

Unified Soil

Classification

E m b a n k m e n t M a t e r i a l

Gravely soil

or

Sand withsome gravel

Compacted

20 40 0 GW, GP

SandWell grained

Compacted20 35 0 SW

SandPoor grainedCompacted

19 30 0 SP

Sand and

Gravel

Compacted19 25 30 or less SM, SC

Fine grained

sand

Compacted

18 15 50 or less

ML, CL

MH, CH

U n d i s t u r v e d M a t e r i a l

GravelDense, or wellgrained

20 40 0 GW

Gravel Not dense, or

poor grained18 35 0 GP

Sand andGravel

Dense 21 40 0 SW

Sand and

Gravel Not dense 19 35 0 SP

SandDense or wellgrained

20 35 0 --

SandLoose or poor

grained18 30 0 --

Silty Sand Dense 19 30 30 or less SM, SC

Silty Sand Loose 17 25 0 SM, SC

CrayStiff, N-value is8-15

18 25 50 ML,CL

CrayModerate,

N-value is 4-817 20 30 ML,CL

Cray

Soft, N-value is

2-4 16 15 15 ML,CL

SiltStiff, N-value is

8-1517 25 50 CH,MH,ML

SiltModerate,

N-value is 4-816 15 30 CH,MH,ML

SiltSoft, N-value is2-4.

14 10 15 CH,MH,ML

(Source: Design Guideline for Japan Expressway)



26/138

2.3 Estimated Soil Modulus by N-value

Table 2.4 shows the relation between internal friction angles and N-values (Reference :

Terzaghi and Peck).

Table 2.4 N-value and Internal Friction Angle (Sand)

N-value DensityInternal Friction Angle

(Degree)

0 to 4 Very loose less than 28.5

4 to10 Loose 28.5 to 30

10 to30 Medium 30 to 36

30 to50 Dense 36 to 41

More than 50 Very dense More than 41

Table 2.5 shows the relation between unconfined compressive strength and N-value

(Reference: Terzaghi and Peck).

Table 2.5 N-value and Unconfined Compressive Strength (Clay)

N-value Consistency

UnconfinedCompressive

StrengthkN/m

2

Cohesion

(for short-time load)

kN/m3

0 to2 Very soft less than 25 less than 12.5

2 to4 Soft 25 to 50 12.5 to 25

4 to8 Medium 50 to 100 25 to 50

8 to15 Stiff 100 to 200 50 to 100

15 to30 Very Stiff 200 to 400 100 to 200

30 or more Hard 400 or more 200 or more



27/138

Chapter 3 Road Drainage

3.1 Design of Drainage

3.1.1 Estimating Discharge

The peak discharge can be estimated by the Rational formula as shown below:

A I C Qd ×××=6.3

1

where: Qd =

C =

I =

A =

peak discharge (m3/s)

runoff coefficient

rainfall intensity (mm/hour) for a critical

time period

drainage area (catchment area) (km2)

3.1.1.1 Drainage Area

The drainage area (catchment area) shall be identified or estimated through field survey

and utilization of topographic map. Each type of road drainage has its designated drainage

area as shown in Table 3.1.

Table 3.1 Drainage Area

Type of Drainage Drainage Area (Catchment Area)

Road Surface Drain Road surface (carriageway and shoulder)

Road Slope Drain Roadside (including road slopes and mountain slopes)

Road Side Drain Road surface and adjoining road slope, adjoining

residential area etc.

Cross Drain Road surface, adjoining road slope, adjoining residential

area and other basin area (if necessary)

3.1.1.2 Runoff Coefficient

The runoff coefficient, C , represents runoff rate of rainfall. The value is provided as

shown in Table 3.2.

Guidebook for Road Construction Maintenance Management 3 - 1


28/138

Table 3.2 Values of Runoff Coefficient, C

Type of Surface Factor C

Cement Concrete or Asphalt Concrete Pavement 0.9 to 1.0Bituminous Surface Treatment 0.7 to 0.9

Gravel Surface 0.3 to 0.6

Residential Area/City 0.3 to 0.6

Residential Area/Town & Village 0.2 to 0.5

Rocky Surface 0.7 to 0.9

Bare Clay Surface 0.7 to 0.9

Forested Land (sandy and clay) 0.3 to 0.5

Flattish Cultivated Areas (not flooded) 0.3 to 0.5

Steep or Rolling Grassed Areas 0.5 to 0.7

Flooded or Wet Paddies 0.7 to 0.8

(Source: DPWH, Design Guidelines, Criteria and Standards)

3.1.1.3 Rainfall Intensity

The rainfall intensity, " I ", is derived from the maximum estimated rainfall for the design

flow return period and time of concentration.

Time of concentration, "Tc", is the time required for runoff from the farthest point of the

drainage area (catchment area) to reach the design target point. Generally, concentration time

can be estimated by the following formula:

385.0

15.1

51 H

L Tc =

where: Tc =

L =

H =

time of concentration in minutes

length of watershed along the mainstream in

meters

difference in elevation between the most

distant ridge in the watershed along the

mainstream and the target point in meters

The design flow return period for the rainfall intensity is provided in Table 3.3.



29/138

Table 3.3 Design Flow Return Period

Structure Type Design Flow Return Period

Bridges 50 yearsBox Culverts 25 years

Pipe Culverts 15 years

Side Drainage 5 years

Surface Drainage 2 years

(Source: DPWH, Design Guidelines, Criteria and Standards)

Rainfall intensity charts were prepared based on the data obtained from PAGASA as

shown in Figure 3.1 and 3.2.

Figure 3.1 Rainfall Intensity Duration Frequency (RIDF) Curves

Source: 328 Baguio Synoptic Station

Figure 3.2 Rainfall Intensity Duration Frequency (RIDF) Curves

Source: 646 Mactan Synoptic Station

0 10 20 30 40 50 60

0

50

200

150

100

250

Duration t (min)

R a i n f a l l R

( m m / h r

500

400

350

300

450100y

50y

25y

10y

5y

2y

Return Period

100 years

50 years

25 years

10 years

5 years

2 years

Duration t (min)

R a i n f a l l R

( m m / h r )

0 380 720 1050 1440

0

40

200

120

100

140

180

160

20

60

80

0 10 20 30 40 50 60

0

50

200

150

100

250

Duration t (min)

R a i n f a l l R

( m m / h r )

100y

50y

25y

10y

5y

2y

Return Period

100 years

50 years

25 years

10 years

5 years

2 years

Duration t (min)

a n a

m m

r

0

20

360 1030720 14400

40

120

60

100

80



30/138

3.1.2 Capacity of Drainage

Discharge of drainage can be estimated by the following formula:

vaQc ×=

2/13/21i R

nv ××=

2/13/21i R

naQc ×××=

where: a =

v =

n =i =

R =

effective cross-sectional area, m2

flow velocity,m/s

Manning’s roughness coefficienthydraulic radius, m

gradient of water surface

3.1.2.1 Manning’s Roughness Coefficient

Table 3.4 shows Manning’s Roughness Coefficient, n.

Table 3.4 Manning’s Roughness Coefficient

Type of ChannelCondition

Best Good Fair Bad

Brick in cement mortar,brick sewers .012 .013 .015 .017

Smooth cement surface .010 .011 .012 .013

Concrete pipe .012 .013 .015 .016

Concrete lined channel .012 .014 .016 -

Cement rubble surface .017 .020 .025 .030

Dredged earth canals .025 .027 .030 .033

Canals with rough stone bed, weeded slope .025 .030 .035 .040

Earth bottom, rubble side .028 .030 .033 .035

N a t u r a l S t r e a m

Clean straight bank .025 .027 .030 .033

Winding .033 .035 .040 .045

Sluggish river weedy reaches .050 .060 .070 .080

Very weedy reaches .075 .100 .125 .150

(Source: DPWH Design Guidelines, Criteria and Standards)

3.1.2.2 Hydraulic Radius

Below are the different formulas in determining the hydraulic radius:



31/138

)cos1( φ −= r H

)2

2sin1(5.0

φ

φ −= r R

))2sin(2

1(

2φ φ −= r a

21

21

2

2

2

1

21

sinsin

)sin(

2112 φ φ

φ φ

+

+

+++

+

=

H or

mm

mm H R

)cot(cot2

)(2

21

2

21

2

φ φ +×=+= H

or mm H

a

φ

φ

sin1

cos

2112 2 +++=

H or

m

m H R

φ cot22

22

×==

H or m

H a

Figure 3.3 Hydraulic Radius Formula

3.1.2.3 Flow Velocity

Table 3.5 shows appropriate range of flow velocity by type of drainage structure and type

of drainage surface. In case the computed actual flow velocity is higher or lower than the

ranges, the structure should be redesigned.

Table 3.5 Appropriate Range of Flow Velocity

Types Range of Flow Velocity (m/sec)

T y p e o f

S t r u c t u r e Road Side Drain 0.5 to 1.0

Pipe Culvert (910mm.) 0.6 to 1.0

Pipe Culvert (greater than 910mm.) 0.8 to 2.0

T y p e o f

D r a i n a g e S u r f a c e

Cement Concrete 0.6 to 3.0

Asphalt Concrete 0.6 to 1.5

Stone/Brick 0.6 to 1.8

Gravel 0.6 to 1.0

Coarse Sand 0.3 to 0.6

Silt 0.1 to 0.2

3.1.3 Specific Discharge Curve

In case the watershed is vast, the specific discharge curve can be applied to estimate the

H B

H B R

⋅+

⋅=

2 m H B

H m B H R

12

)(2

+⋅+

⋅+=

φ

φ

e c H B

H B H o r

c o s2

)c o t(

⋅⋅+

⋅+

H

Φ

r

H

B

Φ

B

H

m・H

1:m(=H:L)

H１：ｍ

Φ2Φ1

１：ｍ1

H１：ｍ

Φ

mH



32/138

peak discharge as shown in Figures 3.4 to 3.6 used by DPWH FCSEC and JICA in March,

2003 under the Project for the Enhancement of Capabilities on Flood Control and Sabo

Engineering.

Figure 3.4 Specific Discharge Curve (Luzon)

Figure 3.5 Specific Discharge Curve (Visayas)

Figure 3.6 Specific Discharge Curve (Mindanao)

1

100

0.1

1

10

1000 100 10 10,000 100,000

Catchment Area A (km2)

S p e c i f i c D i s c h a r g e q ; m 3 / s / ( k m 2 )

Luzon

Return Period

100 years

50 years

25 years

10 years

5 years

2 years

1

100

0.1

1

10

1000 100 10 10,000 100,000


S p e c i f i c

D i s c h a r g e q ; m 3 / s / ( k m 2

Visayas

Return Period

100 years

50 years

25 years

10 years

5 years

2 years

1

100

0.1

1

10

1000 100 10 10,000 100,000


S p e c i f i c D i s c h a r g e q ; m 3 / s / ( k m 2 )

Mindanao

Return Period

100 years

50 years

25 years

10 years

5 years

2 years



33/138

3.2 Cross Drainage

3.2.1 Installation of Cross Drainage

Basically there are three alternatives for vertical alignment of cross drainage as shown in

Table 3.6.

Table 3.6 Installation of Cross Drainage

Alternative-1 Alternative-2 Alternative-3

Figure

Advantages

The construction andmaintenance costs will be

cheaper owing to its simple

design.

Water will be easily drained. The flow might be controlled tomitigate slope and pipe

damages.

Dis-

advantages

The slope of the embankment at

the outlet portion will be prone

to scouring hence, proper

drainage outlet structures

should be provided.

There is no need to provide

drainage outlet along the

embankment slope however,

protective measures at the

outlet portion should be

provided to minimize the

scouring effect of the rapid

flow.

Construction and maintenance

costs are high due to longer

pipes.

3.2.2 Headwalls

Basically, inlet/outlet headwalls for cross drainage should be provided to prevent

scouring and erosion as shown in Figure 3.7.

Figure 3.7 Typical Inlet and Outlet Headwalls



34/138

Figure 3.8 Structure of Headwall

3.3 Underground Drainage

3.3.1 Function of underground drainage

High water contents in road base material enormously affect the strength(bearing

capacity) of the pavement . Figure 3.9 shows the relationship between CBR of road base

material and its water contents.

To keep the road base material in good condition, provision of underground drainage

system is recommended.

Figure 3.9 Relation of Water Content and CBR

Joints between CulvertBox, Wing Wall andApron shall be checkedto be connected watertight.

Apron and Skirt(Toe) shall beconnected to preventwater from seepinginto the bottom ofculvert.Skirt (toe)

1601401201008060

6

4

2

0

C B R

( % )

Water Content (%)

Dumped Stone

with grouted

surface



35/138

3.3.2 Typical Cross Section of Underground Drainage System

Figures 3.10 to 3.12 show typical cross sections of road with underground drainage.

Underground drainage should be recommended as required per existing condition.

Figure 3.10 Typical Underground Drainage for a 2-lane Road

Figure 3.11 Typical Underground Drainage for a 4-lane Road

Figure 3.12 Typical Underground Road Drainage for Mountainous Terrain

3.3.3 Treatment of Seepage from Mountainous Slope

In case of road embankment on the natural slopes, seepage and/or surface water from

mountainous slopes should be treated as shown in Figure 3.13.

Underdrains on both sides of the road

Underdrains on both sides and at the median

Underdrain on one side



36/138

Figure 3.13 Treatment of Seepage from Mountainous Slope

3.3.4 Underground Drainage on Cut and Embankment Portions

Underground drainages shall be installed at cut and embankment portions as shown in

Figure 3.14.

Figure 3.14 Underground Drainages on Cut and Embankment Sections

Under-drain

Cut Slope

Embankment

Under-drain

Construction of Road Embankment on the slope withseepage from side slope

Base Rock Layer

Seepage from side slope

Bench Cut

Recommended treatment of underground water

Cutoff Trenchwith Blind Pi e

Drain Pipe

Drain Layer wrapped with Geotextile



37/138

Chapter 4 Pavement

4.1 Types of Pavement

Road pavement is of two major types - rigid pavement (PCCP) and flexible pavement

(ACP).

Figure 4.1 Conceptual Figure Showing Load Distribution

for Rigid and Flexible Pavements

4.1.1 Rigid Pavement

A rigid pavement generally consists of three layers: the concrete slab, subbase and

subgrad as described below:

Slab The slab is made of reinforced or plain concrete which also includes

load transfer devices and joint sealing materials. The concrete slab

acts like a bridge girder over the subgrade.

Subbase It is the portion of the pavement structure between the subgrade and

the slab. It usually consists of compacted layer/s of granular

materials.

Subgrade It is the bottom portion of the pavement structure which consists of

suitable embankment materials or existing road bed.



38/138

4.1.2 Flexible Pavement

A flexible pavement generally consists of four layers: surface course, base course,

subbase and subgrade (which is the prepared roadbed) as described below:

Surface Course It consists of a mixture of mineral aggregates and bituminous

materials constructed on a prepared base course.

Base Course It is the portion of a pavement structure immediately beneath the

surface course. It consists of aggregates such as crushed stone,

crushed slug, crushed or uncrushed gravel and sand or a combination

of these materials placed and compacted on a prepared subbase.

Subbase It is the portion of the pavement structure between the subgrade and

the base course. It consists of a compacted layer of granular

materials placed on a prepared subgrade.

Subgrade It is the bottom portion of the pavement structure which consists of

suitable embankment materials or existing road bed.

4.2 Portland Cement Concrete Pavement

4.2.1 Quality Control

The Contractor shall perform all sampling, testing and inspection necessary to assure

quality control of the component materials of the concrete. The Contractor shall be

responsible for determining the gradation of fine and coarse aggregates and for testing the

concrete mixture for slump, air content and temperature. He shall conduct his operations so as

to produce a mix conforming to the approved mix design.

4.2.2 Design Mix and Trial Paving

The Contractor is obliged to formulate the design mix, conduct trial mix and trial paving

for approval of the Project Engineer before commencement of pavement construction as

illustrated in Figure 4.2.

Figure 4.2 Flowchart for Preparatory Work for Concrete Paving

Approval of Design Mix andMethodology

Material TestDesign Mix

and Trial MixTrial Paving Start

Paving

4 - 2 Guidbeook for Road Construction and Maintenance Management


39/138

4.2.3 Admixture/Additive

Admixture/additive shall be added only to the concrete mix to produce some desired

modifications to the properties of concrete whenever necessary, but not as partial replacement

of cement. The admixtures shall conform to the requirements as tabulated below:

Table 4.1 Requirements for Admixtures

Type Requirement Remarks

Air-entraining admixture AASHTO M154

Chemical admixture AASHTO M194

Fly Ash ASTM C618 As 20% partial replacementof portland cement inconcrete mix

4.2.4 Concrete Paving ActivitiesThe following photos show concrete pouring activities:

Preparation and cleaning Moistening prior to

placing

Transport of concrete

(for slipform paver)

Placing of Concrete

Conduct of slump test Checking of temperature

of the mix

Checking of the thickness Finishing by means of a

floater

Finishing by means of a

screeder

Checking of the texturing

Tool

Texturing of the surface Spraying of curing

compound

Provision of protective

cover sheets

Sawing of weakened plane

joint

Checking the depth and

width of the joint

Figure 4.3 Concrete Paving Activities



40/138

4.2.5 Types of Formworks

There are two types of formworks for concrete paving - fixed-form and slip form. The

use of slipform paver is required in DPWH road projects as per D.O. 219 Series of 2000.

Using Fixed Form Using Slipform Paver

Figure 4.4 Paving Works

4.2.6 Weakened Plane Joint

All joints shall be protected from the intrusion of injurious foreign material until sealed.

All joints shall be cut within 4 to 24 hours after pouring and thereafter sealed with asphalt

sealant. The depth of the weakened plane joint shall not be less than 50 mm while the width

not more than 6 mm. Only concrete saw is permitted in the cutting of weakened plane joints.

According to international practice, dowel bars are required in all contraction joints (at 4.5m)

as load transfer device for PCCP with thickness of more than 200 mm. The PCCP slabs

without dowel bars at weakened joint will cause various defects in the medium to long term,

especially for the road route on which heavy trucks are dominant. However, this has not yet

become a standard practice of the DPWH due to cost constraints. Presently, the application is

by specific road section and upon approval of the concerned DPWH Office in consultation

with BOD.

The types and functions of PCCP joints are summarized below.



41/138

Table 4.2 Types and Functions of PCCP Joints

Category and Type Function Load Transfer Method

(Device)Longitudinal Joints Formed

Joints

Shrinkage CrackPrevention

Construction by lane

Tie bar(Deformed)

T r a n s

v e r s e J o i n t s * *

ContractionJoint/WeakenedPlane Joint

Formed

Joints


At every 4.5m

With dowel bar*Round Bar *

Without dowelSawed

Contrac

tion

Joint


At every 4.5m

ExpansionJoints

FormedJoints

Expansion ForceRelease

Dowel Bar(Round)

ConstructionJoints

Formed

Joints

Joint for interruption ofwork and end of day’s

construction

Tie Bar(Deformed)

* Bar size varies depending on pavement thickness

**No transverse joint shall be constructed within 1.50 m of concrete block.

Tie Bars for Longitudinal Joints (Deformed Bar)

Dowel Bars (Round Bar)

Figure 4.5 PCCP Joints and Load Transfer Device



42/138


43/138

4.2.8 PCCP Widening

The widening of existing PCCP is one of the common works involved in upgrading work.

Procedures are likely the same as the replacement of deteriorated PCCP slabs.

Figure 4.7 PCCP Widening

Drilling of holes for Tie Bars Placing Concrete

Note) Workers must wear safety gears.

Figure 4.8 PCCP Widening Work

* The provision for widening blocks at curves shall be poured simultaneously with the

adjoining lane.

* Weakened plane joints at curves shall be perpendicular to the centerline.

4.2.9 Temperature Control

The Engineer shall require that measures be taken into consideration to prevent the

temperature of concrete mix from exceeding 32oC because shrinkage cracks occur when the

concrete is placed at a high temperature, which may include any or all of the following:

a) Addition of ice blocks in the water. b) Shading and water sprinkling of aggregates, formworks and steel bars.

c) Shading of working area.

d) In transporting concrete using trucks, provide necessary cover sheets.

e) Placing of concrete at a time when the humidity is low.

Figure 4.9 Thermometer



44/138

4.2.10 Surface Texturing

Surface texturing is necessary to keep a skid resistant surface and is done after the

surface has hardened enough.

Figure 4.10 Texturing of the Surface

4.2.11 SubbaseThe subbase materials shall be spread on the prepared subgrade and compacted to the

required thickness.

Figure 4.11 Laying of Base Materials by Means of Road Grader and Paver

4.2.13 Asphalt Concrete Overlay on PCCP

Asphalt concrete overlay is a standard repair work both for routine and preventive

maintenance. It is laid on the existing pavement after the repair of distress.

In overlaying, preventive measures against reflection cracks shall be considered.

Methods to prevent reflection cracks are as shown in Table 4.4.



45/138

Table 4.4 Preventive Measures for Reflection Cracks on AC Overlay

Types Methods Remarks

Aggregate

Intermediate

Layer

Laying of aggregate base materials

Required

minimum

thickness is 15cm.

Asphalt

Concrete Crack

Relief Layer

Laid over the existing PCCP to prevent cracks from

extending to the newly laid asphalt concrete.

Required

minimum

thickness is 9 cm.

Surface

Treatment

This item shall consist of either a single application of

bituminous material followed by a single spreading of

aggregate (single bituminous surface treatment), ortwo applications of bituminous material each followed

by a spreading of aggregate (double bituminous

surface treatment) in accordance with the Plans and

Specifications.

Crack and Seat

Technology

Cracking of the existing PCC pavement with

dimension of 0.5 x 0.5m. using guillotine or arrow

hammer and rolling it with pneumatic roller.

4.3 Introduction of Newly Approved Pavement Materials

4.3.1 Instapave

Instapave is a technology used for improving road surface condition. It consists of a

blend of Cold Seal Bitumen (CSB), aggregate, water and additives applied on a prime coated

base or on a tack coated concrete/asphalt pavement in accordance with the Plans and

Specifications.

4.3.2 Pavement Dressing Conditioner

Pavement Dressing Conditioner (PDC) is a surface treatment material for asphalt

concrete pavement consisting of a blend of coal tar and petroleum oil. It is designed to

penetrate the pavement surface to replace critical elements necessary to rejuvenate and

rehabilitate the asphaltic binder thereby increasing pavement plasticity and flexibility while

reducing viscosity. Since it has already become an integral part of the pavement, it does not

wear off under traffic and prevents raveling.



46/138

Pavement Dressing Conditioner (PDC) is composed of materials as shown below.

Table 4.5 Material Composition of Pavement Dressing Conditioner

Materials Remarks1. Refined Coal-tar (Gravel RH2) 30% to 40%

2. Light aromatic solvent 30% to 40%

3. Naphtha or coal-tar solvent naphtha 30% to 40%

4. Blend of tar oils 15% to 40%

5. Elastomer 0.01% to 13%

4.3.3 Polymer Modified Bitumen

Polymer Modified Bitumen (PMB) is a material for porous asphalt pavement. The

mixture is open graded asphalt wearing course applied on asphalt concrete or portland cementconcrete pavement.

The porous asphalt mixture is composed of large proportion of coarse aggregate, small

proportion of fine aggregate, mineral filler and PMB.

This mixture has air voids within the range of 18% to 25% that easily allows the passage

of water.

4.3.4 Stone Mastic Asphalt

Stone Mastic Asphalt (SMA) is a gap graded hot mix asphalt surface course composed of

high proportion of coarse aggregate, fine aggregate, mineral filler, bituminous material and

cellulose fiber. Cellulose fibers either pure or bitumen coated, shall be added to the mix to

absorb the excess binder and to improve the properties of the asphalt mix.

Generally, SMA is not applicable on bridge decks.



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Chapter 5 Slope Protection

Works

5.1 Appropriate Slope

5.1.1 Cut Slope

Natural ground is extremely complex and not uniform in its properties and cut slopes

tend to gradually become unstable after the completion of work. Therefore, stability

calculation is necessary only in rare cases when examining the stability of cut slopes. An

overall judgment shall be made by fully taking into account the requirements for its stability

described later by referring to the standard values of the gradient of slope listed in Table 5.1.

Table 5.1 Cutting Height and Cut Slope

Soil/Rock Properties Cutting Height

H

Slope (Ratio)

(H:V)

Hard Rock 7.0 m 0.25:1 to0.5:1

Soft Rock 7.0 m (max) 0.5:1 to 1:1

Soil a. cohesive 2.0 m or less 2:1

Over 2.0 m 1.5:1

b. less cohesive 2.0 m or less 2:1 to 4:1

Over 2.0 m 1.5:1 to2:1

Note:

1. Indicated gradient (ratio) is subject to change

depending on the stability of soil materials.

2. When the cutting height exceeds 7.0 m for rock

materials and 5.0 m. for soil, benching is applied.

3. In case of heavy weathering or erosion, this table is

applicable only after adequate protection work is

applied.

(Source: DPWH FCSEC Technical Standards and Guidelines for Planning and Design Vol. IV)


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For reference, shown below is Japan’s standard gradient for road embankment slopes.

Table 5.3 Japan’s Standard Gradients for Road Embankment Slopes

Materials of EmbankmentEmbankment slope height

(m)

Slope (Ratio)

(H:V)

Sand of well grain size

distribution

5 m or less 1.5:1 to 1.8:1

5 to 15 m 1.8:1 to 1.20:1

Sand of poor grain size

distribution10 m or less 1.8:1 to 2.0:1

Rock lump, rock muck10 m or less 0.8:1 to 1.0:1

10 to 20 m 1.8:1 to 2.0:1

Sandy soil, stiff fine-grained

soil

5 m or less 0.8:1 to 1.0:1

5 to 10 m 1.0:1 to 1.2:1

Volcanic clay 5 m or less 1.8:1 to 2.0:1

Note: Embankment height is defined as from slope toe to slope shoulder.

It is required that there is enough bearing capacity of embankment base and no expected

inundation.

(Source: ‘Highway Earthwork Guideline, Japan Road Association, March 1999’)

5.2 Slope Failure5.2.1 Soil Slope Collapse

* Part of the mountain side slope suddenly collapses on the road.

* Mostly triggered by rainfall infiltration.

* Collapsed/collapsible materials are soil and highly weathered rocks.

* Prone to occur on steep slopes.

* The volume involved is generally from 200 to 5000 cubic meters.

Embankment Height

Slope shoulder

Slope toe


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Figure 5.2 Typical Soil Slope Collapse

5.2.2 Rock Slope Collapse

* Free falling or rolling down of rocks along the slope.

* Falls occur due to gravity and are controlled by the distribution of joints. Materials are

hard, jointed rocks.

* Prone to occur on steep slope and cliff.

Figure 5.3 Typical Rock Slope Collapse


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5.2.3 Landslide

Landslide refers to all types of slope failures and defined as movement of a large mass of

soil and/or rocks.

Charateristics of a landslide are as follows:

* A portion of the road bulges up by an inch or more.

* It is triggered by water infiltration and/or earthquake.

* Materials are soil and highly weathered rocks.

* It usually occurs on a gentle and irregular mountain slopes.

* The volume involved is generally more than 5000 cubic meters.

Figure 5.4 Typical Landslide


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5.2.4 Road Slip

* Road slip occurs because of the

collapse/scouring/caving-in of the valley side

slope of the roadway.

* Occurs mostly on road shoulder.

* Occurs mostly along stream bends.

* Mostly induced by infiltration/leakage of water

from road surface/damaged drainage facilities.

* Materials are soil and highly weathered rocks.

Figure 5.5 Road Slip

Figure 5.6 Typical Road Slip

5.2.4.1 Road Slip Process

Infiltration of rainfall through the cracks accelerates the process of slipping.

Monitoring of these cracks and preventive measures to reduce road slip risks are

necessary such as filling of cracks with impervious materials. A typical process of the

development of open cracks on a shoulder slope is shown in Figure 5.7.

Expansion

→

Sliding/displacement

→

Compression

Figure 5.7 Stages of Road Slip


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5.2.4.2 Road Slip due to Water Infiltration

Water infiltration is a major cause of road slope failure. It is important that inflow from

above cut slope should be controlled and discharged to proper outfall sites.

(Source: Japan Highway Public Cooperation 1982, Slope Inspection Guide 1)

Figure 5.8 Landslide Caused by Water Infiltration from Road

5.2.4.3 Road Slip due to Slope Erosion and Inadequate Drainage

Road slip starts with slope erosion. Slope erosion results from infiltration of water into

the road bed due to inadequate drainage sytems which eventually lead to gradual sliding of the

slope. At this stage, countermeasures will become expensive hence, properly designed

drainage system should be undertaken.

Figure 5.9 Road Slip due to Slope Erosion

Road

Road

Drain

Road

Road Slide

Swelling


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5.3.2 Rock Slope Failure Countermeasures

The following countermeasures are applicable for rock slope:

* Removal and Cutting of

Unstable and Isolated

Rocks

* Slope Drainage Work

* Retaining Wall

* Shotcrete

* Rocknet

* Cribwall

Figure 5.14 Selections of Rock Slope Failure Countermeasures

5.4 Slope Erosion Control

Gentle slope is more stable however, the degree of exposure to erosion is higher. In such

condition, erosion countermeasures such as slope drainage, vegetation, etc. are required.

R a i n f a l l p e r s l o p e a r e a

Slope (o)

Figure 5.15 Relations between Slope and Rainfall

Removal of unstable mass,Retaining wall,

Masonry works,,Catch wall for rolling stones,and/orCombination of above.


Masonry worksCatch wall for rolling stones, Vegetation works (if able),Slope DrainageCombination of above.


Masory works, Vegetation works (if able),Horizontal boring,Shotcrete and/orCombination of above.


Crib wall, Anchor works,Horizontal boring,Shotcrete,Rocknet,Rockshed and/orCombination of above.

YES

YES

YES

NO

NO

NO

Is there high riskof rock slope failureor rock f

Documents

Guidebook for Road Construction and Maintenance Management