Proceedings 1st International Congress on tunnels and underground structures in South-East Europe "USING UNDERGROUND SPACE" April 7-9, 2011, Dubrovnik, Croatia

Seismic Performance Assessment and Rehabilitation of Existing Buildings

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TEACHING MATERIAL ON STRUCTURAL STEEL DESIGN FOR CIVIL / STRUCTURAL ENGINEERING STUDENTS & FACULTIES

Industrial Composting: Environmental Engineering and Facilities Management

Principles of environmental science and technology, Volume 14 (Studies in Environmental Science)

Bentley ProStructures V8i SELECTseries 4 (08.11.04.42) (TRIAL ONLY)

Suport for
• AutoCAD 2009 - 2012, 32 and 64 bit
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Automated Imaging Technologies for Pavement Distress Surveys

Why Buildings Stand Up: The Strength of Architecture

Guidelines for the Use of Pavement Warranties on Highway Construction Projects

This report summarizes the results of research on established pavement warranty programs of various DOTs and identifies programmatic and project-level decision criteria that DOTs may consider when applying pavement warranties on highway construction projects.
The findings of this research are briefly summarized as follows:
• Three types of warranties identified in this research are currently being implemented by practitioners. These are classified as Type 1—materials and workmanship, Type 2— short-term performance, and Type 3—long-term performance.
• The number of pavement warranties implemented by DOTs in the United States varies widely. The number of pavement warranty projects within these DOTs ranges from a very small number to virtually all pavement projects, with certain limitations.
• Few DOT practitioners have developed a systematic approach to project selection. Where warranty decision criteria are used, warranties are often limited to safe projects or stable base conditions. In a very few cases, warranties are used for all pavements unless the existing conditions preclude their use on the entire project or portions of the project.
• Risk allocation on a warranty project can vary greatly depending on the type of warranty implemented and the anticipated project outcomes.
• To implement successful pavement warranty projects, owners must apply the right type of warranties to the right type of project scope of work, and the provisions must effectively manage risk based on the stated objectives and goals for the warranty project.
• A warranty decision tool was developed as part of the research. The tool is available in both manual and automated formats in Microsoft Excel (see Appendix A2). The tool first guides users through a set of programmatic criteria designed to assess whether programlevel issues must be addressed before a DOT can successfully implement and sustain a warranty program. These issues may include DOT or industry resistance to changing the traditional contracting or business model, bonding limitations, resistance to transferring quality or performance risk to the contractor, or a reluctance to move from the lowest initial cost and minimum quality model to aiming for improved quality and reduced
life-cycle costs.
• The warranty decision tool also includes an assessment of the risks of implementing a Type 1, 2, or 3 pavement warranty based on project-specific characteristics and suggests strategies to mitigate these risks. Project-specific characteristics may include project location, size and complexity, existing foundation and base conditions, accuracy of traffic projections, average annual daily traffic (AADT) and traffic phasing requirements, and level of control ceded to the contractor for design, construction, and quality management. If the risks are high for a given warranty type, the tool suggests strategies to mitigate risk by modifying the scope of the project or the warranty or choosing the warranty type that fits with the level of control or responsibility allocated to the contractor under the contract, the accuracy of the traffic projections, or historic pavement performance data for the pavement type.
• Comprehensive warranty guidelines are necessary to assist DOTs in implementing the appropriate warranty type for the specific project or program objectives, allocating risk, and addressing what elements are important to consider when drafting a warranty specification for hot mix asphalt (HMA) or portland cement concrete (PCC). Lastly, the guidelines include model pavement warranty provisions for HMA and PCC pavements that DOTs can use when developing their own project-specific warranty provisions.

Geometric Design Practices for Resurfacing, Restoration, and Rehabilitation: A Synthesis of Highway Practice

The Resurfacing, Restoration, and Rehabilitation (3R) program began in 1976 when the U.S. Congress authorized funding for highway projects that were intended to extend the service life of an existing road. The program originally defined the 3Rs as follows:
1. Resurfacing—Work to place additional layers of surfacing on highway pavement, shoulders, and bridge decks, and necessary incidental work to extend the structural integrity of these features for a substantial time period.
2. Restoration—Work to return the pavement, shoulders, and bridges over a significant length of highway to an acceptable condition to ensure safety of operations for a substantial time period.
3. Rehabilitation—Work to remove and replace a major structural element of the highway
to an acceptable condition to extend the service life of a significant segment for a substantial period of years commensurate with the cost to construct.
Over time, the desire and the requirement to make safety improvements to existing facilities
in need of pavement repair changed the objective of 3R projects to include “enhance safety.” Subsequently, the issue became one of how much an existing roadway should be improved to achieve the safety objective. Should roads requiring pavement repair or other maintenance activities to extend their service life be brought up to full standards for geometric
design or other design features? Doing so would minimize the amount of mileage that could be improved under the limited funding of the 3R program.