Mixing Influences on Cement-Based Waste Forms
High-shear, medium-shear, and low-shear mixing tests were conducted on paste and paste + fly-ash mixes: The specimens, cured for 28-days, were tested for free water generation, compressive...

Biopolymers for Geotechnical Applications
A number of bacteria, e.g., Alcaligenes eutrophus, have been employed to produce large amounts of intracellular polyester, poly-?-hydroxy butyrate...

Advanced Composites Build on Success
Advanced composite materials are competing with conventional structural materials thanks to the ready availability of glass, aramid and carbon fibers, epoxies, vinylesters, polyesters...

Engineered Contaminated Soils and Interaction of Soil Geomembranes
Due to liability issues, landfills are no longer considered the best method of waste disposal. Innovative, safe disposal methods for large quantities of contaminated soils and waste are...

Evaluation of the Troxler Model 4430 Water-Cement Gauge
Prepared by the Highway Innovative Technology Evaluation Center, a CERF Service Center. This report describes a HITEC evaluation designed to determine...

Residual Benefits
Stringent pretreatment and effluent standards and a lack of capacity prohibit their release into sanitary sewer systems. Landfill disposal is costly. The National Pollutant Discharge Elimination...

Lessons from Nonfailures
Two case histories are described in which building owners were told during rehabilitation projects that their structures were in serious trouble. In one case, the engineer told the owner...

Human Extender: A Material Handling System
A human's ability to perform physical tasks is limited by physical strength, not by intelligence. `Extenders' are a class of robot manipulators worn by humans to augment human mechanical...

Dynamics of Laminated Plates with Layer Waviness
Composite structures usually exhibit a high strength-to-weight ratio as compared to traditional structural materials. This makes them attractive solutions in many aerospace applications....

A Membrane Structure for a Lunar Assembly Building
This paper describes potential design options and construction approaches for the development of an inflatable membrane structure of non-circular cross section. This structure could be...

Axisymmetric Vibrations of Thick-Walled Cylindrical Tubes in the Presence of Thermal Residual Stresses
The paper presents an approach to the analysis of axisymmetric vibrations of thick-walled specially orthotropic multilayered cylindrical tubes. The first part of the paper is concerned...

Behavior of Bolted Joints in 3-D Braided Composites
As composites are used more as replacements for metals in space structures, the question arises as to the most efficient way to join the components. Mechanical fasteners are a common joining...

Late Stage Damage in G30-500/PMR-15 Laminates
Damage progression has been studied experimentally under tension using [02/906]s...

Feasibility of Dual Technology in Manufacturing Lunar Concrete
This paper presents the feasibility of utilizing different construction materials for probable use on the moon. Furthermore, it is to our advantage to use what is available on the moon...

Analysis of Glass-Ceramic Production from Lunar Resources
Two simulated regoliths were used to investigate the effects of processing and composition on the properties of lunar-derived glass-ceramics. For the simulant with moderate iron concentration,...

Nonlinear Collapse of Offshore Jacket Structures
The Joint Industry Tubular Frames Project was established with ten oil industry sponsors to investigate the reserve and residual strength of frames typical of offshore structures. To date...

High-Strength Concrete Columns in High-Rise Buildings
Strength and ductility of high-strength concrete columns were investigated by examining available test data. The results are summarized in terms of load and ductility capacities of columns....

Lateral Bracing Criteria of the Composite Braces
In order to simplify the hysteretic characteristics of diagonal steel braces, a lateral bracing problem of unbonded braces embedded in the concrete panel is treated here. Lateral bracing...

Shock-tested R. C. Slabs: Significant Parameters
Shock-tube tests of plain concrete and reinforced concrete (R. C.) slabs were performed. The influence of free water in concrete pores, emphasized in previous tests at a material level,...

Load Rate Effects on Concrete Compressive Strength
Plain concrete cylindrical specimens from six different concrete mixes, 51 mm in length and diameter, were tested in compression quasi-statically at strain rates between 10-6/sec...

 

 

 

 

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