Existing underground pipe jacking methods use a reinforcing rod in a steel tube to obtain structural stiffness. However, some problems such as inconvenience of works and expensive materials resulted from limited working space and reinforcing works are existed. To resolve these problems, a new pipe jacking method, namely PST (Prestressed Segment Tunnel) method, was developed which used joint to ...

This paper provides a comprehensive derivation for thermoelastic damping (TED) in flexural-mode ring gyroscopes, in light of recent efforts to design high rateresolution gyroscopes. Imposing an upper limit on the attainable mechanical noise floor of a vibratory gyroscope, thermoelastic damping in a ring gyroscope is extracted from the equations of linear thermoelasticity. By assuming that it is...

The present paper explores the result of hygrothermic aging of polymethacrylimide (PMI) foam core sandwich composites immersed in different temperature deionized (DI) and sea waters. The prepared specimens were tested for moisture up-take behavior and the resulting property degradation in terms of flexural and flat wise compressive strength. The results indicate that the saturated hygroscopic t...

We study the behavior of mortars where 0%, 10%, 20%, 30%, 50% and 100% of their original natural sand was replaced by ceramic sand in a search of potential new building materials that will help to conserve natural resources and that are environmentally friendly. In this paper, the physical properties of the sands and their derived mortars, including their compressive strength, flexural strength...

Abstract. New systematic experiments reveal that the flexural strength of saline S2 columnar-grained ice loaded normal to columns can be increased upon cyclic loading by about a factor 1.5. The were conducted using reversed over ranges frequencies from 0.1 0.6 Hz and at temperature −10 ∘C on two salinities: 3.0 ± 0.9 5.9 ‰. Acoustic emission hit rate during cycling increases with an increase in...

The purpose of the study is to utilize the chicken feather and finding the mechanical properties of the chicken feather reinforcing with polyester and phenyl ester. The bi-directional CFF reinforced composites were produced with phenyl ester and polyester resins with fiber reinforced composites, the chicken feather fibers (CFF) were cleaned, tested to know the mechanical properties and tensile ...

The aim of this study is to develop a process to produce high-performance cement-based composites reinforced with flax nonwoven fabrics, analyzing the influence of the fabric structure-thickness and entanglement-on mechanical behavior under flexural and tensile loadings. For this purpose, composite with flax nonwoven fabrics with different thicknesses were first prepared and their cement infilt...