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.

Design Guide Handbook for EN 1996 Design of Masonry Structures

The overall aim of this project is to encourage a satisfactory level of adoption of EN1996: ‘Design of Masonry Structures’ within the construction industry during the period that it is coexistent with the UK national codes, particularly BS5628 ‘Use of Masonry’.
The first output was BRE Report No. 213-298. This contained contents lists for the two document outputs - the ‘Handbook for using Eurocode 6’ and the ‘Companion Document to the various parts of Eurocodes 6 and their supporting standards’.
The second output from this project was BRE Report No. 213300, which contained a first draft ‘Design Guide Handbook for EN 1996 – Design of Masonry Structures’.
This report is the third output from this project, and contains a second, revised, draft of the ‘Design Guide Handbook for EN 1996 – Design of Masonry Structures’.

Hot-dip-zinc-coating of prefabricated structural steel components

(1) This JRC-Scientific and Technical Report gives information from pre- normative research methods to avoid liquid metal assisted cracking of prefabricated structural components during zinc-coating in the liquid zinc melt that may impair the structural safety of structures in which the components are built in.
(2) This information provides a platform upon which further European design and
product specifications can be developed. It may in particular affect the further developments of EN 1993, EN 1090 and EN ISO 1461 and EN ISO 14713.
(3) This report gives the state of the art in understanding the mechanism of liquid metal assisted cracking in the zinc bath and methods and models that may be used to avoid it.
(4) It could be a basis to propose rules for the design of steel components intended to be hot-dip-zinc-coated in such a way that the design is consistent with execution rules for hot-dip-zinc-coating.
(5) The workability of the rules proposed for all metal works and steel works that are fabricated under EN 1090 and galvanized according to the rules in this report is demonstrated by worked examples.

Structural and Failure Mechanics of Sandwich Composites (Solid Mechanics and Its Applications)

Mechanics of Elastic Structures