Damage Prediction in Laminated Composites with Continuum Damage Mechanics
A finite element model is developed for laminated composite plates experiencing fatigue load induced microstructural damage. Continuum damage mechanics based constitutive relationships,...
A Materials Study of Interleaved Bismaleimide Composites
One approach for improving damage tolerance in epoxy based composites involves interleafing of tough adhesive layers between plies of the composite prior to fabrication. Extension of this...
Resin Transfer Process Modelling: Computational & Experimental
In most cases, the resin transfer molding (RTM) researcher has a fundamental understanding of composites and possibly some mold design experience. The areas of resin flow dynamics and...
The ENF Test: Critical Analysis and Computational Modelling
We have developed an experimental and computational strategy to moderate the experimental scatter of the interlaminar fracture toughness values (GIIc)...
Long-Term Strength Gain or High Strength Concrete as Monitored by Drilled Cores
An evaluation was made of the relationship between standard cylinders, four-inch by eight-inch cylinders, and drilled cores. The evaluation results showed that the strengths obtained from...
Heat Development and In-Situ Strength of Large Diameter Caissons Made with High-Strength Concrete
The test program essentially consisted of casting two prototype caissons using two different high-strength concretes, measuring internal caisson and adjacent soil temperatures, extracting...
Evaluation of Factors Affecting High-Strength Concrete Cores
A number of factors are discussed to explain different effects they have on core strength. These factors should be considered when evaluating cores tested to determine 'true'...
Compressive Strength Relationship Between Cylinder Tests and Core Tests
A core obtained from any field cured structural member will be inherently different than the field cured cylinder used as a control. Consequently, comparisons with field cured cylinders...
Maturity and Pullout for High-Strength Concrete
As with other types of concrete mixtures, construction with high-strength concrete requires assurance that sufficient levels of in-place strength are reached at specific times. An experimental...
Effects of Physicochemical Factors on Asphalt Aging
A new model for asphalt oxidative aging is presented. The model proposes that the kinetics of low temperature aging in the pavement temperature range is largely governed by physicochemical...
Laboratory Aging of Asphalt-Aggregate Mixtures
Aging may result in hardening (stiffening) of the mixture which will result in a change in performance of the mixture. This may be beneficial since a stiffer mixture will have improved...
Asphalt Age Hardening?Trends and Predictions
Pavement cracking is substantially related to the consistency of asphalt cement binders. The variation in hardness of binders is related primarily to asphalt characteristics, environment...
SHRP Program: Asphalt Durability and Specification
The goals of the Strategic Highway Research Program (SHRP) program are an improved specification for asphalt binders and accelerated performance tests that can be employed by user agencies...
Asphalt Changes in Drum Dryer and Batch Operations
The study was designed to determine whether steam distillation of asphalt takes place in a drum dryer mixer by comparing changes induced by various laboratory conditioning (aging) techniques...
Recognition and Avoidance of Details That Adversely Affect the Performance of Exposed Wood Members
Factors that affect the deterioration of wood in structures are reviewed. Important points regarding wood-moisture relationships are noted. The requirements for decay of wood by fungi...
Methods for Assessing Wood Structures in Place
The Forest Products Laboratory is developing a comprehensive guideline for assessing the condition of existing wood structures. This paper provides an overview of the current literature...
Development of a Plane-Strain Device for Soft Rock
Work is now in progress to build a plane-strain apparatus for 'soft' (unconfined compressive strenghts below 35 MPa) rock and concrete, based upon a passive,...
Combined Compression-Shear Experiments on Mortar-Aggregate Interfaces
Material interfaces between matrix and aggregate particles in cementitious composites such as concrete are considered to be a very important component of the material microstructure, which...
Glued Laminated Timber for Bridge Construction
Structural glued laminated timber (glulam) was first introduced into the U.S. as a construction material in 1934. With the development of fully waterproof adhesives in the 1940's,...
Applications of Wood Materials for Innovative Bridge Systems
This paper describes completed research and the status of research underway on timber bridges that are part of the USDA Forest Service timber bridge initiative. The initiative includes...
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