Pannapa Herabat

A Decision Support System for Flexible Pavement Treatment Selection

This paper discusses the development of the Thailand Pavement Maintenance Decision Support System (TPMDSS), which integrates database management systems and a treatment decision model to provide an effective guideline for flexible pavement treatment selection. The treatment decision model employs a cause-based strategy, which follows a logical progression by synthesizing relevant pavement-related data to help identify pavement problems and recommend feasible treatments. The main components of TPMDSS include an inventory module, field inspection module, pavement section analysis module, distress explanation facility and reporting module. The logical relationship between each module is defined through the use of decision matrices, system rules and scoring systems. The completed prototype has been well-received by Thai Department of Highways practitioners.

MULTIPURPOSE ASSET VALUATION FOR CIVIL INFRASTRUCTURE: ALIGNING VALUATION APPROACHES WITH ASSET MANAGEMENT OBJECTIVES AND STAKEHOLDER INTERESTS

Valuation is a critical component of asset management for civil infrastructure because it provides a means for evaluating facilities whose value is to be preserved or enhanced. Although the basic concept of valuation is generic, there are various quantitative approaches for valuing assets. These approaches can be classified to provide guidance for selecting the right valuation approach to accomplish different asset management objectives. Various approaches are examined for valuing assets in transportation corridor, financial, and corporate real estate asset management from the viewpoint of the purpose of valuation. How different valuation approaches support different purposes is shown, and the importance of selecting appropriate valuation methods to achieve different objectives is discussed. On this basis, some of the critical issues are identified for developing useful valuation classification frameworks to relate valuation approaches with an agency’s asset management objectives and the scope and emphases of stakeholder interests. Building on the purposes of valuation associated with the Governmental Accounting Standards Board Statement 34 requirements, a prototype framework is developed for classifying valuation approaches, and emerging opportunities to expand the scope of valuation tools for multipurpose infrastructure valuation are discussed. The results should be useful to agency staff interested in understanding how various valuation tools can help them to accomplish different asset management objectives as they upgrade their infrastructure management systems to asset management systems.

APPLICATION OF COST APPROACH FOR PAVEMENT VALUATION AND ASSET MANAGEMENT

An application of the cost approach for valuing pavements is presented. Asset management for civil infrastructure has been increasingly promoted since the 1990s, following the Governmental Accounting Standards Board’s infrastructure reporting requirement for state and local governments. There are several ongoing developments in the research, administration, and practice of transportation asset management related to incorporating asset valuation concepts and techniques into existing management systems. To contribute to ongoing developments in this area, a case study is developed to demonstrate an integration of the cost approach for asset valuation with an existing pavement management system and to discuss how the results are useful for asset management. The results demonstrate that the cost approach captures the relationship among pavement value, performance, and time and can be used to capture the added value of pavement maintenance activities. The results also show that the cost approach can be incorporated into various management systems and used as a common basis for evaluating investment trade-offs for different types of infrastructure in order to enhance the overall value of a mixed asset base. The results also indicate that the cost approach can provide a useful common basis and language for discussions among engineers, managers, and stakeholders and is a powerful concept for enhancing the planning and investment decision-making process. The results are potentially useful to agencies involved in upgrading their infrastructure management systems to incorporate asset valuation and to other researchers involved in developing and integrating useful approaches for infrastructure valuation in existing management systems.

Integration of the component of financial statement in highway maintenance planning

Highway agencies attempt to apply efficient accounting systems to help improve the transparency of their budget allocation and their overall performance. The accrual accounting system has been adopted to substitute the cash accounting system by many central governments around the world. The system reports transactions of economic value changes rather than when cash movements are made. The asset value and its depreciation determined by the accrual accounting system illustrate the total amount of economic value owned by an agency and the consumption of the future economic benefits for an asset. The age‐based depreciation approach, which is a traditional approach, is applied to determine the depreciation of an asset based on the defined useful life and the straight‐line depreciation method. The advantage of this approach is its simplicity and its ability to support the long‐term asset management system. The condition‐based depreciation is recommended as an alternative approach since the actual condition of an asset can reflect its depreciation. The depreciation of an asset based on the condition‐based approach is suitable for single‐year maintenance planning since the executives cannot estimate the required budget for replacing or preserving of an asset in the long‐term period. This research focuses on developing the new depreciation approach by integrating the age‐based and the condition‐based depreciation approaches in order to strategically plan long‐term highway maintenance and to enable the actual condition of an asset to be reflected.

Capturing Effects of Maintenance Practices in Highway Asset Valuation: Replacement-Cost Approach Versus Book-Value Method

The replacement-cost approach and the book-value method as decision support tools for selecting maintenance alternatives under budget constraints and for capturing the effects of maintenance practices on highway asset value are investigated. By using a case study based on the Thailand Pavement Management System, the replacement-cost approach and the book-value method are applied to analyze maintenance alternatives for selected highways. The versatility of these asset-valuation methods is explored for capturing trade-offs in the type and timing of maintenance and for incorporating the added value of effective maintenance practices and the impact of deferred maintenance in the overall asset value. The study demonstrated that the replacement-cost approach is a more versatile tool for considering the maintenance-related value of highways in maintenance decision making, whereas the book value may be a simpler financial accounting tool. The two approaches may be used together to clarify how maintenance expenditures are being translated into facility replacement value or how the overall value of the infrastructure is being preserved. The study results are potentially useful to agencies interested in capturing the added value of effective maintenance practices in the overall value of their asset base.

Web-Based Rural Road Asset-Management System

The Department of Accelerated Rural Development in Thailand has undergone major structural reforms according to the direction of National Economic and Social Development Plan 9, which decentralizes government authority into subdistrict levels. The goals for subdistrict level management are to improve the quality of life and the living standard through economic and social development in rural areas. By restructuring the maintenance practice and policy to complement the new orientation of the plan and to enable the proper planning of rural road asset maintenance activities, a systematic rural road asset-management system was implemented to achieve the goal of the subdistrict and central management. A web-based technology was used to provide an easy linkage between the central and the remote offices for both network and project-level management. The organizational barriers, development process, tools and technology, data integration, and benefits of the improved data-management system are discussed. The developed system includes data regarding pavement, bridge, drainage system, traffic sign, pavement marking, and vegetation problems. How web-based information technology can be applied to an asset-management system is discussed. The benefits are measured for productivity, profitability, and rural road user effects.

Finite-Element Analysis for Fatigue Evaluation of Reinforced Concrete Bridge Deck

This paper presents the finite-element procedure for fatigue evaluation of reinforced concrete bridge deck under the application of truck wheel load. The approach is based on the smeared crack concept with the introduction of the fatigue tests of concrete and reinforcing steel available in the literature and the Palmgren-Miner linear criterion of cumulative damage in the analysis. The models are validated with the fatigue test of 1/6.6-scale AASHTO bridge deck under the application of fixed-point repetitive loading presented in previous study. Results are in good agreement. Significant contribution of the developed approach to the fatigue evaluation of bridge deck is a series of S-N relations which can be simulated at any desired levels of damage. This permits the investigation of the deterioration of bridge deck which is appeared to be useful information for highway agencies to prolong the life of their bridge decks. S-N relations are simulated at crack areas of 10%, 20%, 30%, and 40% of the bottom surface area of the deck slab to represent the propagation of crack. Deterioration of bridge deck subjected to passages of five-axle double-unit trucks in Thailand is investigated to demonstrate the application of the simulated S-N relations.

Analysis of Damage Mechanism of Reinforced Concrete Pavement Joint Sealant

Highway agencies in Thailand select reinforced concrete pavement for highways that have to carry a high traffic volume because of the pavements durability and ability to support heavy loads with less deformation. Joint sealant is a structural component that interconnects the pavement slabs. Limited information on the joint sealant is available in Thailand. This research proposes to analyze the damage mechanism of the joint sealant by application of the finite element method under the local environment in which it is subjected to different load patterns, temperature, and time periods. Three-dimensional finite element analysis of the joint sealant and its fatigue property are presented in this paper. Displacement of slab edge surface on both sides of the rigid pavement expansion joint by traffic loading and curling effect can cause stress and strain in the joint sealant. This study conducts an experiment to obtain the fatigue property of the joint sealant subjected to the cyclic movement induced by traffic...