Defects experienced during construction are costly and preventable. However, inspection programs employed today cannot adequately detect and manage defects that occur on construction sites, as they are based on measurements at specific locations and times, and are not integrated into complete electronic models. Emerging sensing technologies and project modeling capabilities motivate the development of a formalism that can be used for active quality control on construction sites. In this paper, we outline a process of acquiring and updating detailed design information, identifying inspection goals, inspection planning, as-built data acquisition and analysis, and defect detection and management. We discuss the validation of this formalism based on four case studies.

concrete (HPC). The scope of the report is expanded somewhat to examine the current body of knowledge on the effects of various curing conditions on the development of the properties of concrete in general. The significance and importance of curing and various proposed definitions of high-performance concrete are discussed. Specific types of the most commonly used high-performance concrete are described, and their properties and characteristics are highlighted. The report summarizes some of the currently accepted concepts and theories of how curing alters the physico-chemical characteristics and structure of a cement paste, since many of these are applicable to the study of highperformance concrete. The landmark studies by Powers and Brownyard in the mid 1940s on the physical and chemical properties of hydrating cement paste are summarized. The history of the American Concrete Institute (ACI) building code requirements for curing are traced from the beginning of this century to the present time. Current curing requirements in the standards of various countries are reviewed and discussed. Some of the recent research in the United States and other countries, related either directly or indirectly to the curing of high-performance concrete, is summarized, including the important work of

Technology, as aids to the efficient transfer of NEHRP and other research into practice, thereby helping to reduce the nation’s losses from earthquakes. National Institute of Standards and Technology The National Institute of Standards and Technology (NIST) is a federal technology agency within the U.S. Department of Commerce that promotes U.S. innovation and industrial competitiveness by advancing measurement science, standards, and technology in ways that enhance economic security and improve our quality of life. It is the lead agency of the National

These guidelines were developed to assist applicants in addressing the seismic design requirements for proposed liquefied natural gas (LNG) facilities. They apply to all new LNG facilities or proposed significant changes to existing LNG facilities under the jurisdiction of the Federal Energy Regulatory Commission (FERC). This document replaces and supersedes “Data Requirements for the Seismic Review of LNG Facilities, NBSIR 84-2833 ” (18 CFR 380.12(h)(5) and (o)(15)). Federal regulations applicable to seismic design of LNG facilities are identified and summarized, and guidance is provided in a number of areas that may be subject to interpretation by technical experts. In general, the guidelines are based on existing rules and procedures found in NFPA 59A, ASCE 7-05, ASCE 4-98, API 650 Appendix E and other current standards documents applicable to LNG facilities. The guidelines also rely on the National Seismic Hazard Maps and the 2006 IBC MCE Ground Motion Maps, which were developed specifically for use in the design of buildings and other structures in the United States by the United States Geological Survey (USGS). This document also provides guidance on the classification of structures, components and systems

close of comment period.

Abstract—Recent historic events have shown that buildings that are designed in compliance with conventional building codes are not necessarily able to resist blast effects. It was observed in the past events that progressive or disproportionate collapse generally occurred due to deficient blast performance of the structure, albeit in compliance with conventional design codes. In the past, safety of structures against blast effects was ensured, to a limited extent, through perimeter control; which minimizes damage by preventing the direct impact of the blast effects on the building. With the emergence of blast resistant structural design, methodologies to inhibit progressive collapse through the structural components performance can be developed, although there are no available adequate tools to simulate or predict progressive collapse behaviour of concrete buildings with acceptable precision and reliability. This paper presents part of an effort to find an affordable solution to the problem. State of the art review of the blast analysis and progressive collapse analysis procedures will be presented. Preliminary analysis has been carried out to establish the vulnerability of a typical multistorey reinforced concrete framed building in Riyadh when subjected to accidental or terrorist attack blast scenarios. In addition, the results of the blast vulnerability assessment will be used to develop mitigation approach to control or prevent progressive collapse of the building.

This report describes research results from the second year of a three-year study focused on the use of recycled asphalt pavement (RAP) and crushed concrete (CC) as backfill for mechanically stabilized earth (MSE) walls. The objectives of the research project are reviewed. The compaction characteristics of RAP and CC are presented, and the effect of compaction on particle breakdown is discussed. Tests to evaluate the accuracy of nuclear gauges, when used to measure the compacted density and water content of RAP and CC in the field, are also discussed. Results indicate that the nuclear gauge overpredicts the as-compacted moist density and water content of RAP and CC. Triaxial strength testing of RAP and CC are presented, and indicate that these materials exhibit adequate strength for MSE wall applications. Results are presented from expansion tests performed on various CC specimens to evaluate the potential for excessive heave or expansion after compaction. Expansion appears only to be a problem when the CC contains significant sulfates, but the sulfate levels necessary to cause problems are not expected to occur in the field. Preliminary results from corrosion tests indicate that RAP and CC do not adversely affect the corrosion rate of metallic strip reinforcement at early exposure periods.

Abstract not found

Project conducted in cooperation with the U.S. Department of Transportation, Federal Highway Administration,

In steel trapezoidal box girder bridge systems, the U-shaped steel girder is designed to act compositely with the concrete deck to form a closed box for live loading. During the construction stage, however, the behavior is not well understood. The usual practice of assuming the system to be non-composite during construction requires substantial top flange bracing to form a quasi-closed box section. Field studies have Composite box girders with live loading, and girders during construction, have to be evaluated during the design of curved steel trapezoidal box girder bridges. Considering both cases, the design for construction loading is the least understood and is the most important. Stresses due to construction loading can reach up to 60-70 percent of the total design stress for a given cross section. A three-phase study was undertaken to investigate the behavior of curved trapezoidal box girders during construction. In the first phase, laboratory tests were performed to investigate the shear transfer between the concrete deck and steel girder at early concrete ages (hours, not weeks). In the second phase, an easy-to-use finite element program, UTrAp, was developed for the analysis of these systems under construction loads and is documented in CTR Report 1898-3 (October 2002). The program has the capability of modeling the effects of semi-cured concrete. The