Estimating Geochemical Behavior of Cocnretes to be Placed at Yucca Mountain
The interactions of J-13 water with cementitious materials were examined at 25?C using the geochemical code EQ3NR/EQ6. Results of the modeling suggested the following conclusions: (1)...
Computer-Based Interactive Design for Prestressed Concrete Structures
Prestressed concrete structures can provide a highly desirable solution for many structural applications because the designer gains control over several additional parameters as compared...
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,...
Optimal Design of Reinforced Concrete Structures via Decomposition and a Variety of Search Strategies
This paper presents a strategy where the design of a reinforced concrete structure is not only automated, but optimized. The strategy employs decomposition to subdivide the problem into...
Optimization of RC Frames with Reliability Concepts
Analysis and design optimization are considered simultaneously for reinforced concrete frames. Global displacements were considered as design variables. The nonlinear behavior of the elements...
Computer Modelling of Concrete Cover Effect on the Behavior of Fiber Concrete Subjected to Monotonic Pullout
The objective of this paper is to evaluate the concrete cover effect on the bond behavior of bars embedded in normal and fiber reinforced concrete. Nonlinear finite element analysis is...
Perplexing Issues in Concrete Softening
We explore some of the proposed techniques for modeling 'softening' via the constitutive model. We seek a framework which is both theoretically sound and physically...
Two Dimensional Analysis of Strain Localization with Nonlocal Continuous Damage
This paper addresses the problem of damage localization from a theoretical stand point with a nonlocal model. Conditions for non uniqueness of the rate equations of equilibrium are derived...
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...
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....
R/C Columns Under Axial and Bi-Directional Lateral Loads
The reliability of a model, called a multi-spring model, was examined to simulate the observed response of reinforced concrete columns subjected to varying high axial loads and bi-directional...
Using a Linearized Yield Surface in Dynamic Analysis
This paper describes an application of the finite element method to dynamic analysis of systems which exhibit material nonlinearity. A time history approach is used with a central difference...
Computational Failure Analysis of Reinforced Concrete Plate Structures
The paper summarizes our recent effort in developing a suitable finite element code for the failure prediction of reinforced concrete structures. The basis of the development is a plasticity...
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....
Nonlinear Response of Ground Supported Slabs
Refined techniques for the structural analysis of ground supported concrete slabs are presented. The principles of limit state design in terms of strength and serviceability are implemented....
Acoustic Emission Source Locations in Concrete
The location of acoustic emission (AE) sources can potentially provide information on the fracture process zone in brittle materials such as concrete. Typical AE experiments generate very...
Bond Strength of Reinforcing Bars in SIFCON
This paper presents a brief summary of an ongoing investigation on the bond characteristics of deformed reinforcing bars embedded in a SIFCON matrix. A significant increase in bond strength,...
Cement and Concrete Characterization by Scanning Electron Microscopy
The scanning electron microscope (SEM) is a powerful tool for the microstructural and chemical characterization of cement and concrete. Imaging techniques such as secondary electron, backscattered...
Moisture Diffusion in Concrete and Mechanisms of Drying Creep
The Pickett effect is the excess of creep at drying over the sum of shrinkage and basic creep. Several theoretical models have been presented to speculate on the mechanisms of this effect,...
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