1

CE 199 Undergraduate Research Project in Civil Engineering 15 April 2013 Final Presentation of Project Transportation Engineering Group

Analyzing Issues on the Design, Construction, and Maintenance of Pavements in the Philippines

MARICAR R. BISCOCHO Undergraduate Student, B.S. Civil Engineering Program

Institute of Civil Engineering, University of the Philippines-Diliman E-mail: cacai_1213@yahoo.com.ph

Advisers: Dr. Jose Regin F. Regidor1

Engr. John Michael Constantino2 1Professor, Institute of Civil Engineering, University of the Philippines-Diliman 2Instructor, Institute of Civil Engineering, University of the Philippines-Diliman

Abstract: There are many factors that can affect the lifecycle of a road pavement. Varying conditions of pavements along the country are attributed to several factors including design factors such as heavy vehicle traffic, and construction and

maintenance practices. Errors in the practice of the application of those factors will reflect to the lifespan of the pavement. Based on the data collected, factors regarding construction practices and quality control, compared to design and

maintenance factors are the most frequent cause of pavement defects and deficiencies. Accuracy in the design factors and quality control must be undertaken for the pavement to serve the traffic for which it was designed. Effective road

maintenance and rehabilitation work is needed to preserve the pavement from further deterioration.

1. INTRODUCTION

1.1 Background of the Study

According to the Department of Public Works and Highways (DPWH) 2011 Year-End Report, Philippines was ranked 100 out of 142 countries in the latest Global Competitiveness Report by the World Economic Forum (WEF) for the quality of roads. Based on the report, Philippines lags behind many of its neighboring countries in the Association of Southeast Asian Nations (ASEAN) in terms of quality of infrastructure, and in particular, the quality of its roads.

For the quality of roads level, WEF has noted a slight improvement in the quality of Philippine Roads from 3.1 on 2010-2011 to 2.8 on 2011-2012. The legend is 1 for extremely underdeveloped and 7 for extensive and efficient by international standards.

1.2 Review of Related Literature

Gaspay, S. M. A, Mata, W. L., Pacheco, B. M., Regidor, J. R. F., Sadie, H. T., and Torio, L. V. (2010) The paper provides a review of the state of practice of road pavement engineering in the Philippines, recommending areas for further study. The review validates that PCCP is more desirable than ACP when both construction and maintenance costs are examined. Directions for further studies have been identified and lean towards investigation of the actual pavement loads, strength and stiffness of

the subgrade, highway drainage, construction engineering and management practices, and total life cycle costs.

Roestler, J. R. et. al. (2000)report addressed design and construction issues as they pertain to long-life rigid pavement strategies. The design and construction issues are discussed with the goal of determining the boundaries of existing technology and approaches to rigid pavement design and construction.

Fisher, J. et. al. (2010) with the Kentucky Transportation Center, Asphalt Institute, and Kentucky cabinet worked together in order to identify factors that affect asphalt pavement density, and to then evaluate their effect on long term pavement performance.

Chan, Y. C. (2008) investigated the relationship between truck overloading and the condition of road damage. The objective is to determine the amount of economic loss due to overloaded truck traffic is. In conclusion, economical loss was found, which include reduction of pavement life and increase in maintenance and rehabilitation cost.

Regidor, J. R. F. et.al (2005) analyzed the traffic inputs to pavement design through assessment of actual highway sections along the Pan-Philippine Highway also known as the Doa Remedios Trinidad Highway. Recommendations are formulated and proposed in relation to the importance of accurate

2

traffic inputs in pavement design, especially the development of heavy vehicle factors that allow for a more accurate estimation of equivalent axle loads as well as implications to economic design of pavements.

1.3 Statement of the Problem

In the Philippines, it can be observed that there are certain roads that were already deteriorated before its expected design life. There are many factors that can affect the lifecycle of a road pavement. Varying conditions of the road pavements along the country are attributed to several factors including those pertaining to the design, geotechnical condition, heavy vehicle traffic, and construction and maintenance practices. [8] Errors in the practice of the application of those factors will reflect to the lifespan of the pavement.

1.4 Objectives

The main objective of this study is to analyze issues on the design, construction, and maintenance of pavement in the Philippines. In the process of realizing this objective, the following tasks are to be undertaken:

a. Identify and define the factors that causes pavement deterioration;

b. Collect data conditions of national roads from the DPWH;

c. Analyze data based on ROCOND Visual Assessment Manual;

d. Determine the most common pavement defects and associate them with the design, construction, and maintenance practices in the Philippines; and

e. Formulate recommendations for improving state of pavement engineering practices in the country.

1.5 Scope and Limitations

The study will focus on national roads only of asphalt and concrete pavement type. Gravel and earth roads, and road components such as shoulders and the like were not included in the analysis.

1.6 Conceptual Framework

The conceptual framework is shown in Figure 4. From the national road assessment data, common defects/deficiencies will be identified. Defects will be ranked according to the percent of occurrences and analyzed using the ROCOND Visual Assessment Manual. Causes of defects will then be categorized and related with the design, construction, or maintenance practices.

Figure 1. Conceptual Framework

1.7 Study Flow

The study flow is illustrated in Figure 5 below. Data collection will be based from reports and publications. Analysis of the data collected will be based on the ROCOND Visual Assessment Manual of the DPWH and Road and Bridge Information Application (RBIA).

Figure 2. Study Flow

2. FACTORS AFFECTING PAVEMENT LIFECYCLE

The factors affecting pavement lifespan based on AASHTO and the DPWH Design Manual are as follows:

2.1 Design Factors

2.1.1Estimation of Traffic for Design

The total volume of traffic expected during the design period of the pavement is estimated by:

= 365 1 + 1

where: T1= traffic volume during the first year TGR= traffic growth rate N = design life in years

TGR is given by:

= 100 + 1 100 + 1 1 100

Common Defects/Deficiencies

(Road Assessment Data)

Design Factor Construction Factor Maintenance Factor

Causes of Defects/Deficiencies

(ROCOND Manual)

Data Collection Data AnalysisConclusion/

Recommendation

3

where: P = annual population growth (%) I = annual growth of income per capita ( %) E = income/passenger transport demand capacity

There are two methods being used in the traffic counting data collection of the DPWH: thru the AutomatedTraffic Counting Machine (ATCM) and Manual count. The automated traffic counting machinesare installed to the identified traffic counting sites that suitable to the equipment eitherpermanently or temporary. The operations of the Automatic Traffic Count and axle load survey are supervised by the Regional Offices while the manual traffic count surveys were assigned to the District Engineering Offices.

The data being produced by the Regional and District Engineering Offices are being forwardedto The Traffic Analysis Section of the Project Evaluation Division, Planning Service through theTraffic Data Entry Worksheet for review and uploading to the Traffic Data Entry Application thatare being processed automatically through the Traffic Data Manager producing Annual AverageDaily Traffic (AADT) and Equivalent Standard Axle Load (ESAL).

Below is the process of traffic estimation of the DPWH:

Figure 3. Traffic Estimation Process of the DPWH

2.1.2 Axle Loadings

AASHTO pavement design procedure requires traffic evaluation for both design and rehabilitation. Since the pavement of the new roads or that under rehabilitation is usually designed for periods ranging from 10 to 20 years or more, it is necessary to estimate and predict the design loads for this period accurately. The accuracy of estimating the design traffic is affected by many factors as follows:

a. Correctness of equivalency factors used

b. Accuracy of traffic volumes and weight information

c. Prediction of traffic loading over the design life

Overloading is one of the causes of pavement cracking which appears to be the most frequent type of distress a pavement experiences. One reality that is critical to Philippine roads is the increase of overloaded vehicles, particularly overloaded cargo trucks that have brought about considerable damage.As overloaded trucks passed along roads, their weight put tremendous pressure on road surfaces. The heavier the load and the slower the speed of the overloaded vehicles, the more unnecessary pounding the road has to take that causes premature deterioration of the road infrastructure.

2.1.3 Strength and Stiffness of the Subgrade

California Bearing Ratio (CBR) is used in assessing the strength and stiffness of both subgrade and pavement materials. The CBR test requires that samples are:

i. truly representative of the soils that will form the subgrade of the road;

ii. compacted to the same dry density as may reasonably be expected to be produced by compaction equipment in the field; and

iii. of a moisture content representing the worst equilibrium conditions in the subgrade under the pavement.

2.1.4 Highway Drainage Design

Poor drainage is one of the causes of cracking on asphalt pavements. Rainfall, if allowed to penetrate the pavement structure or the underneath soil will have a detrimental effect on the strength properties of the structure. Drainage facility is needed to drain the water away from the pavement structure. It is noted, therefore, that effective design of highway drainage is also a must.

2.2 Construction Practices and Quality Control

Many of the causes of pavement deterioration were related to the method of construction and materials used in pavement layers construction. Defects due to unsuitable method and materials can be avoided by proper monitoring and quality control of the pavement during its construction.

In the criteria for quality control performance rating for offices of the DPWH, 75 % of it is for the effectiveness of quality control implementation which comprises timeliness of materials testing, compliance to quality control policies, and quality of completed work. Project supervision which includes project/resident/materials engineers and laboratory

4

personnel weighs 15 % of the rating. The remaining 10 % is for the adequacy/reliability of laboratory equipment and facilities. Table 1 shows the criteria for quality control performance rating.

Table 1. Criteria for Quality Control Performance Rating

2.3 Maintenance and Rehabilitation

Pavement maintenance is needed to preserve the pavement from further deterioration. Applying treatment to the pavement structures on time restores the pavement quality and structural integrity. It also increases the life expectancy and prolongs the service life for additional few years.

The Bureau of Maintenance is primarily tasked with the maintenance of the nation's infrastructures and also engaged in the continuous upgrading of the technical skill of its personnel, through their attendance of various relevant technical courses and seminars. Field inspections were also done to effectively monitor maintenance activities of the district / city offices.

Since 2004, the DPWH has developed and implemented a Pavement Management System (PMS) for the management and maintenance of national road network comprising cement concrete, asphalt concrete and unsealed roads. The main component of the PMS consists of a database which stores road condition, inventory and traffic information.

Road condition data as mentioned is needed in the PMS. DPWH published ROCOND Manual or the Visual Condition Assessment Manual which is adopted from the ROCOND 90 manual of the Roads and Traffic Authority of South Wales, Australia. This publication is a manual for condition reporting which may be used to:

a. Measure and record condition throughout the road system;

b. Describe the condition of the road at the time of rating;

c. Provide a sequence of recorded condition that can be analyzed to indicate performance trends;

d. Provide condition data for pavement related items for utilization in a Pavement Management System (PMS); and

e. Provide condition information on which a Routine Maintenance Management System (RMMS) budget can be based.

3. DATA COLLECTION

Project assessment for Annual Rating of Quality Control Performance in Project Implementation by the DPWH for year 2012 was the data used for the analysis. DPWH conducts assessment of ongoing and completed projects implemented by the department to ensure compliance to specification requirements.

Out of 4,179 projects that underwent assessment for the year 2012, 61% (2,559) was accounted as roads. 1,689 of the total number of roads assessed were concrete roads and the rest were asphalt roads.

Based from the report, the following tables show the frequency distribution of defects/deficiencies in concrete and asphalt pavements:

Table 2. Frequency Distribution of Defects/Deficiencies in Concrete Pavements

(Population: 1,689 Projects)

Table 3.Frequency Distribution of Different Types of Cracks in Concrete Pavement

Table 4.Frequency distribution of defects/deficiencies in Asphalt Pavements (Population: 870 Projects)

Table 5. Frequency Distribution of Defects/Deficiencies in Base/Sub

(Population: 2,559 Projects)

4. DATA ANALYSIS AND DISCUSSION

4.1 Data Analysis

From the data gathered, it shows that pavement cracking is the most common type of defect forconcrete pavements with transverse cracks having the most numbered. According to the ROCOND cracking is one of the most frequent forms of distress and one of the most significant. Raveling is the most common type of defects for asphalt pavements. the progressive loss or disintegration of pavement material, typically occurring in the wheel pathother hand, use of oversized base/submaterial is the most common defect in base/submaterials. Table below summarizes the padistress type and their major causesROCOND Manual.

Table 6. Pavement Distress Type and Major Causes for ACP (Asphalt Concrete Pavement)

5

ion of defects/deficiencies avements (Population: 870 Projects)

Distribution of Defects/Deficiencies in Base/Sub-base

(Population: 2,559 Projects)

AND DISCUSSION

From the data gathered, it shows that pavement type of defect for

concrete pavements with transverse cracks having the ROCOND manual,

cracking is one of the most frequent forms of distress aveling is the most t pavements. It is

the progressive loss or disintegration of pavement material, typically occurring in the wheel path. On the

se of oversized base/sub-base course material is the most common defect in base/sub-base

Table below summarizes the pavement distress type and their major causes from the

. Pavement Distress Type and Major Causes for ACP (Asphalt Concrete Pavement)

Table 7. Pavement Distress Type and Major Causes for PCCP (Portland Concrete Cement Pavement)

Summing up the common defects/deficiencies for asphalt and concrete pavement, the distress type with the highest percent occurrence is concrete pavement cracking, followed by raveling on asphalt pavements with 56.17% and 51.26% occurrenceTable 8 shows the top 5 common defects/deficiencies with high occurrences.

Table 8. Common Defect/Deficiencies with High Occurrences

Major causes of the defects Manual with high occurrences are9 below.

Table 9. Major Causes of Common Defect/Deficiencies with High Occurrences

There are different weight factors for each type of distress that will sum up to total distress experienced

. Pavement Distress Type and Major Causes for PCCP (Portland Concrete Cement Pavement)

the common defects/deficiencies for and concrete pavement, the distress type with

the highest percent occurrence is concrete pavement cracking, followed by raveling on asphalt pavements

% occurrence, respectively. common defects/deficiencies

. Common Defect/Deficiencies with High Occurrences

Major causes of the defects based on the ROCOND with high occurrences are tabulated in Table

Major Causes of Common Defect/Deficiencies with High Occurrences

There are different weight factors for each type of distress that will sum up to total distress experienced

6

by the pavement. Tables 10 and 11 show the asphalt and concrete distress weight factors.

Table 10. Asphalt Distress Weight Factor

Table 11. Concrete Distress Weight Factor

Cracking of pavement has the highest weight factor for both asphalt and concrete, which means that the cracking governs the total weighed distress.

Sum of weighted distress for asphalt pavement is given by: = !"#$% + &%' )' " + *!#$% 1.25+ .*./'0 0.36+ 1 !' 2 #/1'0 0.18+ 1**#$% 4 4+ ' #$% 1 !' &''!*0

On the other hand, sum of weighted distress for concrete pavement is given by: = !"#$% + 6 //#$% 3+ 2 1/*#$% 4.2+ **''& / 70 1.36+ 8.#$* ' / $* 0.13+ ! /#$%

Computation of Visual Condition Index (VCI) for asphalt and concrete pavement is given by

9 =4 :1,100 1 0??@ABCDE ???? FG

H

Based on the VCI, surface conditions of roads are rated.

Table 12. Condition Rating

For this study however, causes of defects were ranked according to their frequency, since what is being analyzed is the design, construction and maintenance practices and their effect to the pavement, not the condition rating of the roads.

Common causes of pavement defects were categorized as design, construction, and maintenance and monitoring factor. The three development stages were then ranked according to their frequency. Table13 shows the matrix.

Table 13. Causes vs Factor Matrix

4.2 Analysis of Issues on Pavement Design, Construction, and Maintenance

A pavement is designed to withstand an estimated load throughout its lifespan. Its lifespan is a function of the design, quality of construction, and maintenance operations. The design and construction quality control the rate at which the road deteriorates and in effect dictate the maintenance workload throughout the life of the road.

Accumulated damage from vehicles primarily causes deterioration of roads. The occurrence of overloading truck traffic will shorten the lifespan of the pavement. It also induces incorrect estimation in the Equivalent Standard Axle Loads (ESALs), therefore the frequency of maintenance and rehabilitation within

7

the service period are corrupted by the overloaded traffic. Construction practices also affect the maintenance level needed by the road pavements. Many roads were being rehabilitated earlier due to early deterioration because of construction malpractice. Proper quality control during the construction of road projects will lessen the frequency and level of rehabilitation of the roads, minimizing the maintenance costs.

5. CONCLUSION AND RECOMMENDATIONS

Based on the result of the analysis, quality control Based on the result of the analysis, factors related to construction practices primarily affect the service life of road pavements. Quality control performance in project implementation is the important factor in the longevity of the lifespan of a pavement. The quality of construction works plays a crucial role in determining the deterioration rate and service life of a pavement. Engineering properties of pavement materials must always be under control as there are standard procedures and lab tests to assure the quality of the materials and mixtures provided.

DPWH conducts Annual Rating of Quality Control Performance in Project Implementation to evaluate implementing offices of their quality control performance. This will provide proper construction and institutional measures to be executed. Proper monitoring of the projects being implemented will assure quality. Quality control rating will also identify if additional trainings of the project engineers and inspectors must be provided. Development of Quality Management System will be a tool for proper quality management of projects being implemented by the department.

Traffic loading associated factors, which includes traffic volume and axle loading estimation for number of ESALs determination, were also major factors that affects pavement performance and service life. Accurate traffic estimation is needed for both transportation planning and pavement design.

Due to increasing number of overloaded vehicles, RA 8794 or the Anti-Overloading Law must be strictly implemented to decrease the number of overloading trucks. This requires manpower that will enforce the law as well as adequate number of weighing equipment.

Effective road maintenance and rehabilitation work is needed to preserve the pavement from further deterioration. DPWH has developed and implemented a Pavement Management System (PMS) for the management and maintenance of national road network. Its database stores road condition, inventory and traffic information. A Department Order issued by the department requires daily inspection of roads for identification of defects and deficiencies. This is

crucial since early detection and effective rehabilitation of defects will reduce the rate of deterioration and cost of maintenance.

Results encourage further studies to be able to elaborate more on the identified factors affecting the pavement lifecycle. The study recommends future studies that will compare the design lifespan versus the actual lifespan of a pavement by analyzing the factors that might affect it.

6. REFERENCES

[1] Department of Public Works and Highways-DPWH (2012) Annual Rating of Quality Control Performance in Project Implementation. Manila, Philippines.

[2] Department of Public Works and Highways-DPWH (2012) ATLAS 2011. Manila, Philippines.

[4] Department of Public Works and Highways-DPWH (2006) ROCOND Visual Condition Assessment Manual Philippine Version No. 7. Manila, Philippines.

[5] Department of Public Works and Highways-DPWH (2012) 2011 Year-End Report. Manila, Philippines.

[6] Fisher, J.,Graves, C.,Blankenship, P.,Hakimzedeh-Khoee, S., and Anderson, M. (2010) Factors affecting Asphalt Pavement Density and the Effect on Long Term Pavement Performance, Kentucky Transportation Center, College of Engineering, University of Kentucky.

[7] Gaspay, S. M. A., Mata, W. L., Pacheco, B. M., Regidor, J. R. F., Sadie, H. T., and Torio, L. V. (2010) An Environmental Scan of Road Pavement Engineering Practice in the Philippines.

[8] Regidor, J.R.F., Damaso R.A., and Bilugan, A.R.P. (2205) Assessment of Traffic Inputs to Pavement Design and Rehabilitation. Philippine Engineering Journal.PEJ 2005, Vol. 26. No. 2:1 -12.

[9] Roestler, J.R., Harvey, J.T., Farver, J., and Long, F., (2000)Investigation of Design and Construction Issues for Long Life Concrete Pavement Strategies. Pavement Research Center, Institute of Transportation Studies, University of California.