Our Aging Coastal Infrastructure
The River and Harbor Act of 26 May 1824, signed by President James Monroe, authorized the first involvement of the United States Federal government in the construction of harbor works...

Engineering a Monument, Evoking a Nightmare
Rather than simply standing as a backdrop for exhibits, the $53.2 million U.S. Holocaust Memorial Museum is intended to be part of the fabric of the exhibition itself. Now under construction...

A New Fast Track for Public Works
Most public contracts are still awarded to the lowest bidder, but some states are experimenting with other approaches for complex projects. In Oregon, officials facing a tight deadline...

Passive Acoustic Emission for Quantitative Evaluation of Freeze Thaw and Alkali Aggregate Reaction in Concretes
Several experiments are reported in which the progression of freeze thaw (FT), alkali-aggregate reaction (AAR), and internal cracking caused by mechanical loading were monitored using...

Damage Assessment in Concrete Using Acoustic Emission
An acoustic emission (AE) is a localized rapid release of strain energy in a stressed material. This energy release causes stress waves to propagate through the specimen. These acoustic...

Concrete Beam Testing with Optical Fiber Sensors
The use of an embedded multimode optical fiber to monitor curing and load-to-failure testing of a reinforced concrete beam has been investigated. The embedding process used to network...

A Critique of the Ultrasonic Pulse Velocity Method for Testing Concrete
The pulse velocity method is the most widely used ultrasonic nondestructive method for assessing concrete quality. However, it has been well established that the relation between ultrasonic...

Frequency Spectrum Analysis of Ultrasonic Testing Signal in Concrete
Description is given on high-speed sample apparatus connected with the CTS-25 low frequency ultrasonoscope and computer, the time domain of ultrasonic testing signal is transformed to...

Evaluation of Compressive Strength for High-Strength Concrete by Pulse Velocity Method
Development of compressive strength and pulse velocity for high-strength concrete from the age of 5 hours are studied in relation to cementitious material types and curing conditions....

Simulated Field Trials of Non-Destructive Concrete Test Methods for Highway Structures
The data presented results from a two year Strategic Highway Research Program investigation into suitable NDT methods for determining the early age, and residual strengths of highway structures....

Nondestructive Crack Identification by Acoustic Emission Analysis and Ultrasonic Frequency Response
Nondestructive evaluation (NDE) by the acoustic emission (AE) analysis and the ultrasonic testing (UT) on the spectral (frequency) response is studied to identify crack geometry. AE waveform...

Review of NPP Concrete Degradation Factors and Assessment Methods
Degradation of concrete in nuclear power plant (NPP) structures can be an age-related phenomena. Several research programs have been initiated by the U.S. Nuclear Regulatory Commission...

Pullout Testing of High-Strength Concrete Members
An experimental investigation of a high-strength concrete mixture was undertaken to measure and evaluate pullout and compressive strength properties. Two columns, a slab, and cylindrical...

Concrete Surface Characterization Using Optical Metrology
The displacement of the surface of a concrete specimen is measured as it cures using an optical method. This method, known as optical metrology, is one in which a line is projected onto...

Shrinkage Measurements in Composite Beam Slabs
When the concrete slab on a composite beam shrinks, it is restrained by the steel beam to which it is connected. Tensile stresses, as a result, are developed in the restrained concrete...

Howdy, Partner
Litigation has long been a nemesis to the construction industry. In recent years, contractors and owners have used innovative alternative dispute resolution (ADR) techniques, such as arbitration,...

Piles Over Problems Sites
It's increasingly difficult to find suitable space for construction in urban areas. Pile foundations can fill the void by making questionable and heavily regulated sites,...

Life in the Fast Track
Through innovative financing and skillful construction management, Oklahoma is proving that transportation megaprojects are still possible, even during an economic downturn. The result...

Project Management: Keys to Success
Successful construction projects can be traced to several key factors observed by the owner, the AE and the contractor. They include: 1) Goals and commitment of the managing partners agreed...

Double Diamonds: New Brand for a Texas Bridge
Double diamond towers, distinctive as a cattle brand but tall as a 44 story building, have reached landmark status on the Texas Gulf Coast even though the bridge they will carry won't...

 

 

 

 

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