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...
Friction and Cohesion in Ice Rubble Reviewed
An argument is ventured that accumulations of ice rubble undergoing continuous shear deformation are essentially cohesionless. In terms of the Mohr-Coulomb failure criterion, therefore,...
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...
Low-Rise Shear Wall Failure Modes
A summary of the data that are available concerning the structural response of low-rise shear walls is presented. These data will be used to address two failure modes associated with shear...
Structural Approximations in Multi-Story Buildings
Simplified computer analyses and various approximate hand calculation methods are extremely valuable in structural engineering for multi-story buildings both during the preliminary design...
Strain Distribution in Fault Zones and Fluid Flow
Field and laboratory studies have shown that mechanical shearing in fault zones produces a repeatable fabric that changes with increasing shear strain. In the brittle field of mechanical...
Correlation of Hydraulic Conductivity and Sonic Velocity in Water-Saturated Tuff
A laboratory study was conducted to investigate the correlation of hydraulic and sonic properties of water-saturated tuff. The hydraulic test used a new rock block testing machine, which...
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,...
Macro-Model for Inelastic Low-Rise R.C. Shear Walls
This paper presents an analytical technique for calculating static and seismic response of low-rise shear wall structures. The displacement response is resulting from bending, shear, and...
Finite Element Analysis and Design of Plywood Shear Walls
An integrated procedure for the analysis and design of rectangular plywood shear walls is presented and illustrated. The analysis is done using an in-house finite element program with...
Finite Element Studies of Block Shear for Structural Tees
Structural tees are commonly used as tension members. As a first step toward testing the adequacy of the current design codes for net section and block shear failures near the connections...
Prediction of Transverse Shear Stresses for Various Isoparametric Thick and Thin Shell Elements
Utilizing three-dimensional equilibrium equations (often referred to as an Equilibrium Method (EM)), an estimation of transverse stresses for fiber-reinforced laminated doubly curved shells...
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....
Chaotic Advection in a Shear Layer
The developing (in time) inviscid shear layer, although not yet in its turbulent regime, displays all the characteristics of chaotic advection. The corresponding Lyapunov exponent is strictly...
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