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...
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...
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...
Use of Geogrids on Soft Deposits
The construction of highway embankments over soft and waste deposits required the use of geogrids as an economical alternate to conventional methods of 'remove and replace'....
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...
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...
Fiber Reinforced Plastic Grids for the Structural Reinforcement of Concrete
The use of fibre resin plastic grid is investigated as a primary bending reinforcement in concrete members. Laboratory bending data is compared with theoretical results using ACI 318-83...
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...
Durability of Fly Ash Concrete in the Marine Environment
This paper presents the experimental investigation of durability of air-entrained fly ash concrete in the marine environment. The findings indicate that the deterioration rate of durability...
Effect of Fly Ash on the Microstructure and Durability of Concrete
The influence of fly ash on the microstructure and durability of concrete was investigated. It was found that the use of 50% fly ash in concrete reduced greatly its resistance to freezing-and-thawing...
Permeability Effects on the Sulfate Resistance of Concrete
A laboratory study was conducted to determine the effect of permeability on the sulfate resistance of concrete containing fly ash. Concrete specimens were moist cured for 7 and 100 days...
High Performance Fiber Reinforced Cement-Based Composites
Fracture of cement-based composites reinforced by the relative high fiber volume is studied. Crack propagation and damage distribution were examined by laser holographic interferometry....
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