August 30, 2004

Controlling Concrete Cracking and Curling

By: Matthew Sherman, Paul Kelley, Bae Jewan

Abstract: Drying shrinkage is a trait of concrete that, if poorly controlled or managed, can lead to serviceability problems, reduced durability, and even system failures. Cracks from restraint of shrinkage can reduce the performance life of...

August 30, 2004

Comparative Performance of Buckling-Restrained Braces and Moment Frames

By: Ronald Mayes, Craig Goings, Naguib, Wassim I., Stephen Harris, Lovejoy, Jennifer, Fanucci, Jerome P., Bystricky, Pavel, Hayes, John R.

Abstract: This paper will provide a comparison of the maximum inter-story drifts and floor response spectra for 3 and 9 story buildings using both steel and aluminum BRBs designed with an R-factor of 7. The buildings had the same dimensions as...

July 30, 2004

Development of next-generation performance-based seismic design guidelines

Abstract: The Applied Technology Council has initiated the ATC-58 project to develop next-generation performance-based seismic design guidelines applicable to the design of new buildings and upgrade of existing buildings. The guidelines will...

June 29, 2004

Slip and Wear in Multi-Layer Azimuth Track Systems

Abstract: Many antennas use wheel-on-track systems in which track segments consist of wear plates mounted on base plates. The hardened wear plates are typically connected to the base plates using bolts, and the base plates are supported on grout...

June 29, 2004

Replacement of Elevation Structure to Upgrade Haystack 37-m Radio Telescope

Abstract: Haystack, MIT's 37-m radio telescope, was built in the early 1960s. At the time considered to be a high-performance antenna, Haystack produced a number of outstanding scientific results. The antenna, originally designed to operate...

June 29, 2004

Evaluating Existing Plaza Waterproofing Systems

Abstract: Reconstructing a plaza deck is often expensive because it involves removing and replacing such overburden elements as paving, plants, soils, and other landscaping features. Access to the plaza for reconstruction work can be difficult...

May 30, 2004

Service Life Tests for Roofing Membranes

By: Cash, Carl G., Bailey D.M., Paroli R.M., Arthur Davies, David Niles, Delgado A.H.

Abstract: This research measured selected physical characteristics of twelve roofing membranes before and after oven heat and ultraviolet exposure. To make these data useful for comparing values, identical test methods and conditions were used...

May 30, 2004

Wear Estimation of a Wheel-on-Track System for Radio Telescopes

By: Rose, Brian D., Frank Kan, Joseph Antebi, Juneja, Gunjeet

Abstract: Many radio telescopes are supported by wheel-on-track systems composed of wheel bogies and wear plates mounted on base plates. In some installations, migration of the wear plates 
has been observed between the wear and...

May 30, 2004

Leak-tracking techniques: how to find non-roof related leaks

Abstract: When is interior water damage not the result of a roof leak? Wall leaks, plumbing leaks, and condensation can be interpreted as coming from the roof. How do you find the source? Visual examinations of interior and exterior surfaces...

May 30, 2004

Slate and Clay Tile Roofing Defy Father Time

On older roofs, high-quality clay tile or natural slate frequently outlast the original metal flashings and roofing underlayment, for example, asphalt-saturated felt paper that help to make the roof watertight. The question frequently facing...

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