CT characteristic analysis of sea-sand concrete exposed in simulated marine environment

The landing string is an important component of deepwater riserless drilling systems. Determination of the dynamic characteristics of the landing string plays an essential role in its design for ensuring its safe operation. In this paper, a dynamic model is developed to investigate the dynamic response characteristics of a landing string, where a landing string in a marine environment is modeled as a flexible slender tube undergoing coupled transverse and axial motions. The heaving motion of the drilling platform is taken as the upper boundary condition and the motion of the drilling bit caused by the interaction between the rock and the bit as the lower boundary condition. A semiempirical Morison equation is used to simulate the effect of the load imposed by the marine environment. The dynamic model, which is nonlinearly coupled and multibody, is discretized by a finite element method and solved by the Newmark technique. Using the proposed model, the dynamic responses of the displacement, axial force, and moment in the landing string are investigated in detail to find out the influences of driving depth of surface catheter, platform motion, bit movement, and marine environment on the dynamical characteristics of the landing string.

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The Characteristic Analysis of Calcareous Deposit Films Formed on Steel Plate by Cathodic Current Process in Marine Environment

Journal of the Korean institute of surface engineering ◽

10.5695/jkise.2016.49.2.166 ◽

2016 ◽

Vol 49 (2) ◽

pp. 166-171

Author(s):

Jun-Mu Park ◽

Jae Wook Kang ◽

In-Hye Choi ◽

Seung-Hyo Lee ◽

Kyung-Man Moon ◽

...

Keyword(s):

Marine Environment ◽

Steel Plate ◽

Characteristic Analysis ◽

Cathodic Current ◽

Calcareous Deposit ◽

Current Process

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Effect of Chloride on Tensile and Bending Capacities of Basalt FRP Mesh Reinforced Cementitious Thin Plates under Indoor and Marine Environments

International Journal of Polymer Science ◽

10.1155/2016/7162313 ◽

2016 ◽

Vol 2016 ◽

pp. 1-7 ◽

Cited By ~ 3

Author(s):

Yan Xie ◽

Kunhua Guan ◽

Lin Lai

Keyword(s):

Thin Plate ◽

Marine Environment ◽

Salt Water ◽

Basalt Fiber ◽

Thin Plates ◽

Indoor Exposure ◽

Hot Air ◽

Sea Sand ◽

Bending Capacity ◽

Marine Environmental

This paper presented a durability experimental study for thin basalt fiber reinforced polymer (BFRP) mesh reinforced cementitious plates under indoor and marine environment. The marine environment was simulated by wetting/drying cycles (wetting in salt water and drying in hot air). After 12 months of exposure, the effects of the chloride on the tensile and bending behaviors of the thin plate were investigated. In addition to the penetration of salt water, the chloride in the thin plate could be also from the sea sand since it is a component of the plate. Experimental results showed that the effect of the indoor exposure on the tensile capacity of the plate is not pronounced, while the marine exposure reduced the tensile capacity significantly. The bending capacity of the thin plates was remarkably reduced by both indoor and marine environmental exposure, in which the effect of the marine environment is more severe. The tensile capacity of the meshes extracted from the thin plates was tested, as well as the meshes immersed in salt solution for 30, 60, and 90 days. The test results confirmed that the chloride is the reason of the BFRP mesh deterioration. Moreover, as a comparison, the steel mesh reinforced thin plate was also tested and it has a similar durability performance.

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Preparation of sea water sea sand high performance concrete (SHPC) and serving performance study in marine environment

Construction and Building Materials ◽

10.1016/j.conbuildmat.2020.119114 ◽

2020 ◽

Vol 254 ◽

pp. 119114 ◽

Cited By ~ 1

Author(s):

Tianyu Li ◽

Xiaoyan Liu ◽

Yumei Zhang ◽

Heng Yang ◽

Zihan Zhi ◽

...

Keyword(s):

Marine Environment ◽

High Performance ◽

High Performance Concrete ◽

Sea Water ◽

Performance Study ◽

Sea Sand

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Long-Term Performance of Seawater Sea-sand Concrete (SSC) Columns Wrapped with CFRP Strips Under Simulated Marine Environment

Journal of Physics Conference Series ◽

10.1088/1742-6596/2148/1/012039 ◽

2022 ◽

Vol 2148 (1) ◽

pp. 012039

Author(s):

Junlong Yang ◽

Ziru Wang ◽

Jizhong Wang

Keyword(s):

Marine Environment ◽

Concrete Strength ◽

Failure Process ◽

Natural Seawater ◽

Test Results ◽

Reinforced Polymer ◽

Sea Sand ◽

Long Term Performance ◽

Term Performance

Abstract This article presents a durability study of carbon fiber-reinforced polymer (CFRP) partially wrapped seawater sea-sand concrete (SSC) columns exposed to natural seawater to explore the effect of exposure duration on the long-term performance of the specimens. Thirty-two cylinders were wrapped with CFRP jackets and exposed to different times of wet-dry cycles (up to 360 days) in an outdoor simulated marine environment. Test results indicate that exposure has no obvious influence on the failure process and ultimate strains of specimens, but the compressive strengths of confined columns (fcc) increase with the increment of exposure time, especially for the partially confined concrete specimens. Moreover, due to the significant variation of unconfined concrete strength fco*), the retentions of fcc and fcc/fco * exhibit an opposite trend. Therefore, the increase of fco* should be considered when using the parameter of the confined-to-unconfined ratio of strength to evaluate the long-term performance of the specimens.

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