Detection of Cracks in Reinforced Concrete Cans
The Acoustic Emission Technique (AET) is known as a good possibility for non destructive detection of cracks in metal down to very small dimensions. To use AET for concrete, an efficient...
On the Modelling of Damage Due to Volumic Variations in Cementitious Composites
Two kinds of volumic variations are considered. Those due to thermal gradients on hardened concrete and those due to hydration processes at early ages. Models based on damage mechanics...
Strain-Based Damage Deactivation in Concrete
Motivated by the 'mode I' microcrack opening and closing mechanism, a procedure for the deactivation of the damage is developed. Strain based projection operators are used to negate the...
Functional Analysis in Continuum and Structural Mechanics
Following brief historical remarks, the equations of the hypercircle and hypersphere of Prager and Synge and associated formulae for pointwise bounds are derived. The application of the...
The Microstructure of Hardened Cement Paste and Concrete
Concrete is a composite material created from a mixture of a binder (hardened portland cement paste) and a filler (fine and coarse aggregates). Like any other composite material the physical...
Computational Framework for 3D Nonlinear Discrete Crack Analysis
Under contract from the Electric Power Research Institute (EPRI) to investigate the applicability of fracture mechanics to concrete dams, the authors are involved in the development of...
Shear Resistance Models for Concrete Bridges
Statistical models are developed for the shear resistance of concrete bridge girders. Two structural types are considered: reinforced concrete T-beams and prestressed concrete AASHTO girders....
An Elastoviscoplastic Model for High Strength Concrete
An elastoviscoplastic model of overstress type is proposed for high-strength concrete in this study. With its viscosity parameters determined with experimental data from the split-Hopkinson-pressure-bar...
Mechanical Properties of High Performance Concretes
This paper presents some of the initial results of a 4-year research project on mechanical properties of high performance concretes with particular reference to highway applications. High...
Scattering of Waves by Steel Reinforcement in Concrete
The application of wave-sensing methods to the non-destructive evaluation of concrete structures requires often the use of simple (or at least tractable) models for the solution of the...
Constitutive Modeling of Slurry Infiltrated Fiber Concrete (SIFCON)
Slurry Infiltrated Fiber CONcrete (SIFCON) is a unique material, containing 5 to 18 percent, by volume, of steel fibers; in contrast, standard Fiber Reinforced Concrete (FRC) usually contains...
Modeling Bond Stress-Slip of Reinforcing Bars Embedded in SIFCON
A brief description is given of the mechanisms associated with the bond shear stress versus slip response of deformed reinforcing bars embedded in slurry infiltrated fiber concrete (SIFCON)....
Stability of Beams in Eccentrically Braced Frames
As the link yields and strain hardens in an eccentrically braced frame, the beam segment-outside of the link is subject to a combination of high axial force and bending moment. For certain...
Investigation of Parametrically-Induced Excitation in Concrete Columns
A mathematical model is developed which accounts for the non-linear material characteristic of concrete members. The axial and transverse motions of concrete columns, are found to be second-order...
Genesis: The Creation of a Lunar Base
A lunar basing scenario that utilizes lunar resources to manufacture lunar concrete modules is considered. An eleven year basing program, starting with initial robotic exploration and...
Design Concepts for a Lunar Concrete Production Facility
This paper discusses concrete production fundamentals on the earth and identifies applicable features required for lunar concrete production. Production principles unique to the lunar...
Lunar Oasis
The Lunar Oasis emphasizes development toward self-sufficiency in order to reduce dependence on the Earth for resupply and to enable expansion utilizing indigenous resources. The Oasis...
Building a Space Infrastructure: The Reclamation Experience
The third and last duty of the ... commonwealth is that of erecting and maintaining those public institutions and those public works, which, although they may be in the highest degree...
A Horizontal Inflatable Habitat for SEI
The inflatable habitat described in this paper is a horizontally-oriented cylindrical pneumatic structure. It is part of NASA's ongoing effort to study inflatables as alternative habitats...
Hedratecture in Severe Climates
There are still vast areas of the world that are almost untouched by human activity. There is need to make access to these regions with special new structures and there is also a need...
Return to search