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...
Rate Effects in the Deformation of Rocks
This paper gives a brief review of creep and rate effects on the behavior of rocks, within a wide range of confining pressures and temperatures, and with a special emphasis on the physical...
A Microplane Constitutive Model for Soils
A microplane model for the inelastic behavior of soils is presented. The microscopic constitutive equations are defined independentely for a set of microplanes covering all possible orientations,...
Rate Effects on Fracture of Concrete
An analytical and experimental investigation of mode I (tensile and mixed mode (combined tensile and shear) fracture of concrete subjected to impact loading was conducted. The rate of...
Creep of Polycrystalline Ice
This paper discusses the extension of creep models for polycrystalline ice to include the effects of a non-monotonic loading history. Attention is focussed on cyclic loading since it is...
Improved Prediction of Masonry Durability Through Advanced Materials Science Methods
Several trends in the use of materials in civil engineering have made it imperative to improve the ability to predict the durability of masonry. This will require more emphasis on materials...
Premature Failures of Outdoor Masonry Pavements
The authors have investigated and repaired a number of premature inservice failures of masonry paving systems in recent years. These systems have become common, built over underground...
Building Joint Movement
Moisture leakage in masonry claddings occurs not only through copings and facial separation cracks, but also through failed sealant joints in the veneer. The factors affecting joint movement...
Use of Voluntary Consensus Standards by the Bureau of Reclamation
This paper outlines how the Bureau of Reclamation has historically participated in standards development for emerging technologies, and how present standards are applied or adapted for...
Asphalt Cement Specifications and HMA Performance
The standard specifications generally used for hot mix asphalt (HMA) are those published by the American Society for Testing and Materials (ASTM) or the American Association of State Highway...
Are ASTM Standards Enough?
ASTM (American Society for Testing and Materials) is most likely the World's most renown developer of voluntary consensus standards. Its standards development process utilizes...
Construction Quality Assurance for Geomembranes
The results of and lessons learned from construction quality assurance (CQA) programs on 19 geomembrane liners are presented. The specifications are generally exceeded by comfortable margins...
Geocomposites Simplify Methane Barrier/Venting System Design
A case history describing the use of a geomembrane and geocomposite to simplify the design of a combined subsurface barrier and venting system is presented. The passive barrier and venting...
Spectral Techniques for Serviceability and Durability Assessment of High-Performance Construction Materials
Using spectral techniques, one can obtain the frequency content of a material specimen. Spectral measurements were made on specimens of Portland cement and a polymer based materials. In...
Return to search