Laboratory Methods for Preparing Low-Density Frozen Saline Soil Samples
Laboratory methods were developed for preparing low-density frozen saline soil samples with density values ranging from 85-110 lb/ft3. This range...
The Effect of Loading Rate on the Bending Strength of Alluvium Reinforced Ice
Traditional building materials are often less than ideal for construction in remote Arctic locations. Their mechanical properties may be degraded in extreme cold, and costs associated...
New Admixtures for Cold Weather Concreting
Chemicals were tested for their ability to promote strength gain in portland cement concrete at low temperature. The admixtures depressed the freezing point of the mix water and accelerated...
Preliminary Results of Direct Tension Tests on First-Year Sea Ice Samples
We present the initial results of our tests to determine the tensile behavior of columnar sea ice over a range of temperatures extending from -20 to -3?C and strain rates of 10-5...
Fly Ash Grouts for Subsidence Control
A laboratory investigation was undertaken to examine procedures for evaluating candidate grouts and to develop quality grouts for use in abandoned mines. The objective of this grout application...
Superplasticized High-Volume Fly Ash Structural Concrete
This research was carried out to develop structural grade concrete containing high-volumes of ASTM Class C fly ash. A Portland cement concrete, proportioned to have 28-day compressive...
Prestressed Concrete Bridge Design and Optimization
The computer program described here analyzes simple span highway bridges for any AASHTO live load, generates girder and slab dead loads, performs the analyses for maximum moments and shears,...
Nonlinearities and Imperfections in Creep Stability
The effects of material and geometric nonlinearities and imperfections on the 'safe-load-limit' and the 'safe-service-period' of structures...
Tensile Failure in Concrete by Spallation
Plate impact experiments were performed on concrete specimens to study tensile failure at high strain rates. For tensile stress pulse durations of 1.5 and 2.2 ms the threshold stress for...
On Isotropic and Anisotropic Damage Variables in Continuum Damage Mechanics
The present work analyzes the implication and limitation of some 'scalar damage' models. In particular, the elastic-damage thermodynamic potential and the 'effective...
Healing or Negative Damage in Concrete
The deformation of concrete may be attributed to damage or the evolution of microcracks and to mechanical healing or the closing of microcracks. For damage, dissipation is positive but...
One Surface Model for Concrete with Non-Associated Damage Rule
The general formulation of a continuum theory for the inelasticity of concrete is derived. The internal theory of thermodynamics is used and the dissipation inequality is established....
Three-Dimensional Finite Element Analysis of Stress and Activation in the Heart
A finite element (FE) method has been developed for three-dimensional (3D) analysis of stress distributions and activation patterns in the left and right ventricles of the canine heart....
Biomechanical Model of a Lumbar Intervertebral Joint?A System Approach
This study was conducted to determine the forces sustained by the lumbar ligaments under flexion-compression using a two-dimensional equilibrium model. The lumbar motion segment was modeled...
Normal and Tangential Contact of Layered Spheres as Models of Joint Contact
The causes of cracking in degenerating cartilage are examined using analytical models of layered elastic spheres in normal and tangential contact. Vertical surface and deep radial cracks...
Buckling Loads of Columns Made of Viscoelastic Materials
This is about the developing of relationships for predicting the change of buckling loads of columns made of viscoelastic materials under different loads. When a columnlike structural...
A Mixture Finite Element for Reinforced Concrete
A semi-analytical finite element is presented for analyses of cracked reinforced concrete (RC) structures including bond action between rebar and concrete, and crack-face shear transfer....
Interlaminar Fracture Toughness Test: Traditional and Modified
For brittle, transversely isotropic, composite materials we have developed an alternative Mode II interlaminar fracture toughness test (GIIc) that...
On the Adhesive Strength of Viscoelastic Fibrous Composites
A methodology for solving problems of anisotropic materials using the theory of elasticity (viscoelasticity) is presented. Some results on specific problems related to the stressed-and-deformed...
Statistical Strength Analysis of Composites
A new modified six parameter Weibull distribution model has been adopted to analyze strength data structure of ARALL laminated and graphite-epoxy composites. This model shows better correlations...
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