Floating Concrete Barge Assessment and Inspection Plan: N’Kossa Case Study, a Large Pre-Stressed Concrete Floating Production Unit in Operation in Congo

2014 ◽  
Author(s):  
Pascal Collet ◽  
Nicolas Vaucquelin ◽  
Arnaud Bury
Keyword(s):  
Water Depth ◽  
Concrete Structure ◽  
High Performance ◽  
High Performance Concrete ◽  
Production Unit ◽  
Close Inspection ◽  
Clear View ◽  
Long Time ◽  
Integrity Management

The paper describes the way a large pre-stressed concrete Floating Production Unit (FPU) located offshore Congo on N’KOSSA field has been inspected and assessed in order to meet both Bureau Veritas Class and Floating Units Integrity Management System (FUIMS) requirements. This FPU is the largest existing pre-stressed concrete barge. She was built with high performance concrete, installed offshore in 1996 in 170 m water depth. She has now accumulated 18 years of production. A significant part of the methodology is based on close inspection for the concrete structure, a graphic assessment of the defects and an implementation of monitoring. This assessment is done a long time after construction and we had to cope with difficulties relative to the structure size, loss of data, barge in operations off-shore. It gives a good feedback of what we should implement during the design and the construction to keep a clear view of the concrete barge integrity.

Structural Integrity Management for a Large Pre-Stressed Concrete Floating Production Unit

2007 ◽  
Author(s):  
Bertrand Lanquetin ◽  
Pascal Collet ◽  
Jose Esteve
Keyword(s):  
High Performance ◽  
Structural Integrity ◽  
High Performance Concrete ◽  
Element Model ◽  
Linear Analysis ◽  
Production Unit ◽  
Non Linear ◽  
Integrity Management ◽  
Field Production

Offshore Floating Production Units, usually deployed under long-term plan, handle the field production so they cannot be easily removed for dry-docking and repair. In order to constantly analyze and monitor the condition of the units, a tailor-made methodology has been developed and implemented since 2004 for the Integrity Management of our Floating Units currently in operation. The paper gives a description of this methodology, and then focuses on how the methodology was deployed for the large pre-stressed concrete Floating Production Unit (FPU) located offshore Congo on N’KOSSA field. This FPU is the largest existing pre-stressed concrete Floating Production Unit, built with high performance concrete, installed offshore since 1996 in 170 m water depth. She has now accumulated 10 years of production. A significant part of the methodology is based on a full Finite Element Model (FEM) with non-linear analysis capacity for the concrete structure, incorporating a description of passive and active steel. There is often an anchored perception that a concrete unit is something not requiring attention once installed. This paper shows otherwise, underlining the complexity of modeling the highly non linear characteristics of pre-stressed high performance concrete and degradation modes.

Early-Age Autogenous Shrinkage of High-Performance Concrete Columns by Embedded Fiber Bragg-Grating Sensor

2009 ◽  
Vol 419-420 ◽  
pp. 1-4 ◽  
Author(s):  
Ying Wei Yun ◽  
Ii Young Jang ◽  
Seong Kyum Kim ◽  
Seung Min Park
Keyword(s):  
Fiber Bragg Grating ◽  
High Performance ◽  
High Performance Concrete ◽  
Construction Material ◽  
Autogenous Shrinkage ◽  
Strain Sensor ◽  
Bragg Grating ◽  
Early Age ◽  
Long Time ◽  
Sensor Temperature

High-performance concrete (HPC) as a promising construction material has been widely used in infrastructures and high-rise buildings etc. However, its pretty high autogenous shrinkage (AS) especially in its early age becomes one of the key problems endangering long-time durability of HPC structures. This paper carried out the early age AS research of large scaled HPC column specimens by embedded Fiber Bragg-Grating (FBG) strain sensor. Temperature compensation for FBG strain sensor by thermocouple was also attempted in this paper, and the results were reasonable and acceptable comparing with the result compensated by FBG temperature sensor. Reinforcement influence, size effect and temperature effect on HPC AS were also analyzed respectively in this paper.

Applying Research on Testing Compressive Strength of High Performance Concrete with Rebound Method

2012 ◽  
Vol 452-453 ◽  
pp. 106-109
Author(s):  
Zheng Jun Wang ◽  
Felix Zhao
Keyword(s):  
Compressive Strength ◽  
Concrete Structure ◽  
High Performance ◽  
High Performance Concrete ◽  
Cement Concrete ◽  
Construction Quality ◽  
Concrete Construction ◽  
Estimation Models

In order to grasp timely and accurately quality of high performance concrete, detection of compressive strength of high performance concrete can be non-destructively, rapidly and accurately tested that is very testing index. The paper did some research on compressive strength of high performance concrete applying redound method that it established several estimation models between rebound value and compressive strength. Experiment shows that rebound method can effetely test compressive strength of high performance concrete. Construction quality of Cement concrete structure can timely grasp applying the method.

Nanoadditives - Future of High Performance Concrete

2017 ◽  
Vol 908 ◽  
pp. 83-87
Author(s):  
Martin Labaj ◽  
Jaroslav Válek ◽  
Tomáš Jarolím ◽  
Lucia Osuská
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
High Strength ◽  
Concrete Surface ◽  
Cement Stone ◽  
Hardened Cement ◽  
Concrete Technology ◽  
High Quality ◽  
Long Time ◽  
The Impact

These days it is almost impossible to imagine the technology of high performance concrete without the use of any kind of additive. Whether it is a material capable of achieving high strength, excellent mobility of the fresh mix without losing cohesion or producing high quality architectural concrete surface, microadditives have their certain place for a long time now. Although the research in this field still has something to offer, it does not hurt to try to consider the future and imagine the path that will be taken in the production of high performance concrete of next generation. The article deals with the possibility of using nanoparticles in concrete technology. These materials can actively participate in the creation of very high-quality cement stone. In addition, due to the extreme reactivity of nanoparticles, these reactions can take place almost immediately after the onset of hydration and during its first hours. The experimental part of the paper assesses the impact of nanoparticles on selected properties of fresh cement paste and hardened cement mortar. In all cases, there was a positive effect and it has been demonstrated that nanoparticles may eventually create a new category of high performance concrete additives.

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