Crack spacing for offshore structures

2008 ◽  
Vol 35 (12) ◽  
pp. 1446-1454 ◽  
Author(s):  
M. Hossin ◽  
H. Marzouk
Keyword(s):  
High Strength Concrete ◽  
Experimental Testing ◽  
High Strength ◽  
Offshore Structures ◽  
Concrete Cover ◽  
Crack Spacing ◽  
Structural Safety ◽  
Building Structures ◽  
Offshore Structure ◽  
Strength Concrete

The main focus of this investigation is directed toward the examination of crack-spacing expressions suitable for offshore concrete structure applications. Offshore structures are unique structures that are constantly exposed to harsh environmental conditions, including exposure to seawater and sea spray. The splash zone of an offshore structure is the section of the platform that is the most exposed to both a harsh marine environment and seawater. The design of offshore structures is controlled by mandatory design codes to ensure structural safety and integrity. Most of the available expressions for crack spacing were developed for building structures using normal-strength concrete and normal concrete cover. However, offshore structures are built using high-strength concrete with a thick concrete cover. Very little information is published on the crack analysis of high-strength concrete with a thick concrete cover for offshore applications. An experimental testing program was designed to examine the effects of concrete cover and the bar spacing of normal- and high-strength concrete on crack spacing. The different code expressions are evaluated with respect to the experimental results.

scholarly journals Teoría y experiencias en el incremento de ductilidad de los hormigones de alta resistencia reforzados con fibras de acero.

2012 ◽  
Vol 2 (3) ◽  
pp. 131-148
Author(s):  
Manuel Fernández Cánovas
Keyword(s):  
Reinforced Concrete ◽  
High Strength Concrete ◽  
High Strength ◽  
Offshore Structures ◽  
Blast Waves ◽  
Steel Fibers ◽  
Structural Elements ◽  
Gas Reservoirs ◽  
Strength Concrete ◽  
Impulsive Loads

RESUMENLas acciones de impacto y cargas impulsivas provocadas por misiles o choque de aeronaves sobre edificios de contención de reactores nucleares o sobre grandes depósitos de almacenamiento de gas licuado, o de vehículos o buques contra pilas de puentes, plataformas petrolíferas marinas, etc., o de ondas explosivas sobre edificios civiles o militares, siempre han tenido una gran importancia en ingeniería, pero las tienen más en estos últimos tiempos debido a la proliferación de actos terroristas. Las estructuras sometidas a estas acciones deben presentar un comportamiento diferente a las tradicionales debido a las grandes cantidades de energía que tienen que absorber y disipar en tiempos muy cortos, de aquí que los elementos estructurales formados por hormigón y acero, tengan que poseer una ductilidad suficiente para que mediante grandes deformaciones anelásticas no llegue a colapsar. En experiencias realizadas frente a acciones dinámicas parecidas a las provocadas por los sismos o a la acción de explosivos o de impacto de proyectiles hemos podido comprobar como el confinamiento de los elementos estructurales conseguido con armadura tradicional y fibras de acero puede producir una ductilidad notable. Este artículo tiene por objeto presentar los resultados de algunos trabajos de investigación en los que se muestra el comportamiento de elementos de hormigón armado reforzado con fibras de acero frente a este tipo de acciones.Palabras clave: ductilidad; impacto; cargas impulsivas; sismos; hormigón de alta resistencia; fibras de acero; cráter de salida.ABSTRACTImpact and impulsive loads such of those caused by missile and aircraft impact on nuclear containers or big liquated gas reservoirs, vehicles or ships in collision with bridges piles or offshore structures, or by blast waves on civil and military buildings or shelters, have played an important role in civil engineering, but today these actions reach a transcendental role because the proliferation of terrorist menaces. The behaviour of structures under these actions must be different of traditional ones, because of the big quantity of energy they must absorb and dissipate in a very short time, so structural elements formed by reinforced concrete must have ductility enough to reach large anelastic strains without failure. In tests carried out by us in high strength concrete structural elements under impact of projectiles or dynamic actions, similar to those produce by seismic movements, we have checked how with a confinement by means of steel stirrups with the complement of steel fibers is possible to reach a notable ductility. The goal of this article is to present the results of some research works carried out showing the behaviour of reinforced concrete with steel fibers elements against these type of actions.Keywords: ductility; impact; impulsive loads; earthquake; high strength concrete; steel fibers; scabbing.

Effective Elements of Building Structures from Pipe Concrete

2019 ◽  
Vol 945 ◽  
pp. 80-84
Author(s):  
O.E. Sysoev ◽  
A.Y. Dobryshkin ◽  
Ye.O. Sysoyev
Keyword(s):  
Cross Sections ◽  
High Strength Concrete ◽  
High Efficiency ◽  
High Strength ◽  
Strength Properties ◽  
Building Structures ◽  
Strength Concrete ◽  
Concrete Pipe ◽  
Bending Load ◽  
Concrete Elements

The article is devoted to the investigation of pipe-concrete prestressed structural elements with high efficiency. This is due to a more complete use of the strength properties of structural materials in the pipe-concrete beam. The article presents various methods for calculating pipe-concrete elements. The design of a concrete tube with a prestressed element using high-strength concrete is presented. The results of calculations of various designs are shown and the cross-sections of beams for perception of the same bending load are selected. A comparison is made between the consumption of beam materials of various designs. The effectiveness of the use of pipe-concrete elements for receiving bending loads made of high-strength concrete with prestressed reinforcement is shown in comparison with the construction of beams of traditional high-strength concrete, high-strength concrete pipe-concrete with no prestressing of reinforcement and metal beam, mass of the element, consumption of metal and concrete.

scholarly journals Flexure Behaviour of Reinforced High Strength Concrete Elements Affected by Corrosion

2019 ◽  
Vol 289 ◽  
pp. 10009
Author(s):  
Camelia Negrutiu ◽  
Ioan Sosa ◽  
Bogdan Heghes
Keyword(s):  
High Strength Concrete ◽  
Limit State ◽  
High Strength ◽  
Concrete Cover ◽  
Ultimate Limit State ◽  
Accelerated Corrosion ◽  
Strength Concrete ◽  
Significant Strength ◽  
Bending Capacity ◽  
State Position

Corrosion of the reinforcement is a constant vulnerability for reinforced concrete structures exposed to aggressive environments. High strength concrete is known to prevent corrosion of the reinforcement, in a non-cracked state, when exposed to aggressive environments. The purpose of this study is to assess the opportunity of using high strength concrete in cracked elements exposed to corrosion and compare them with non-exposed elements. A series of simply supported reinforced high strength concrete beams with concrete cover of 25 and 50 mm were pre-cracked, up to a service life crack of 0.1 mm, further exposed to accelerated corrosion through a process of electrolysis and finally tested to failure. A series of non-exposed witness specimens were also tested to failure. All elements were designed with the same bending capacity. The flexure behaviour was assessed by plotting experimental and theoretical ultimate limit state position of the neutral axis at midspan and the results show no significant differences in the overall behaviour, despite the affected reinforcement, between the corroded and non-corroded elements. Moreover, the design bending moments were approximately 40% lower than the experimental ones, even for corroded beams, which can be a significant strength reserve of the beams, useful in aggressive environments.

Influence of Fiber Type on Behavior of High-Strength Concrete-Filled FRP Tubes under Concentric Compression

2013 ◽  
Vol 438-439 ◽  
pp. 240-245
Author(s):  
Thomas Vincent ◽  
Togay Ozbakkaloglu
Keyword(s):  
High Strength Concrete ◽  
Experimental Testing ◽  
Fiber Type ◽  
High Strength ◽  
Experimental Investigations ◽  
Fiber Types ◽  
Compressive Behavior ◽  
Research Attention ◽  
Strength Concrete ◽  
Frp Tubes

This paper presents results from an experimental study on the behavior of circular high-strength concrete (HSC)-filled fiber reinforced polymer (FRP) tubes (HSCFFTs). Concrete-filled FRP tubes (CFFTs) have received significant research attention over the last two decades and experimental investigations into the axial behavior are abundant for normal-strength concretes (NSC) confined by either carbon FRP (CFRP) or class FRP (GFRP). However, the same cannot be said for CFFTs filled with HSC or manufactured with other fiber types such as aramid or high-modulus carbon FRP (AFRP and HMCFRP), where experimental testing is very limited. To address this research gap, this study examined the compressive behavior of 24 test specimens prepared with three different fiber types (CFRP, HMCFRP and AFRP) and manufactured with HSC. The experimentally recorded stress-strain relationships are presented graphically and the influence of fiber type and other key experimental outcomes are discussed. The results indicate that fiber type has a significant influence on the axial compressive behavior of HSCFFTs.

scholarly journals Thin-walled building structures with improved properties for high-rise construction

2019 ◽  
Vol 265 ◽  
pp. 05004
Author(s):  
Valentina Solovyova ◽  
Makhmud Abu-Khasan ◽  
Dmitry Solovyov
Keyword(s):  
High Strength Concrete ◽  
High Strength ◽  
Silica Sol ◽  
Housing Construction ◽  
Building Structures ◽  
Cesium Nitrate ◽  
Strength Concrete ◽  
High Rise ◽  
High Efficient ◽  
Thin Walled

A high-efficient complex reactive composition consisting of a polycarboxylate polymer, cesium nitrate (CsNO3) and silica sol was developed for cast-in-place housing construction from high-strength concrete. The use of this composition provides production of high-strength concrete with increased crack resistance.

scholarly journals Acoustic Emission Monitoring of High-Strength Concrete Columns Subjected to Compressive Axial Loading

Materials ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3114
Author(s):  
Rami Eid ◽  
Boris Muravin ◽  
Konstantin Kovler
Keyword(s):  
Acoustic Emission ◽  
High Strength Concrete ◽  
Large Scale ◽  
Axial Loading ◽  
High Strength ◽  
Concrete Columns ◽  
Concrete Cover ◽  
Premature Failure ◽  
Strength Concrete ◽  
High Strength Concrete Columns

Acoustic Emission (AE) nondestructive tests have attracted great interest for their use in the determination of structural properties and behavior of reinforced concrete (RC) elements. One of the applications this method can contribute to is in high-strength concrete (HSC) columns. These elements have a great advantage in the lower stories of high-rise buildings. However, the premature failure of the concrete cover and the brittleness nature of the failure is of a concern for engineers. This paper presents a study on the AE monitoring of HSC columns subjected to compressive axial loading. The study consists of four large-scale reinforced HSC columns with different confinement reinforcement and height. It is shown that the AE distributions in the columns are categorized by three stages. Moreover, the levels of loads reached at the first AE macro event are similar to the lower range levels of the nominal axial compressive strengths of the tested specimens, while the majority of macro AE events are located at the concrete cover. Based on the results of this study, AE monitoring can provide indications for the damage and load levels attained by reinforced high-strength concrete columns subjected to compressive axial loading.

Finite Element Analysis on Impact Factors of Castellated Steel Reinforced High Strength Concrete Beams

2015 ◽  
Vol 744-746 ◽  
pp. 141-147
Author(s):  
Er Cong Meng ◽  
Wen Xiang Zeng ◽  
Xiu Li Qiu ◽  
Yi Sheng Su
Keyword(s):  
Finite Element ◽  
Ultimate Strength ◽  
High Strength Concrete ◽  
High Strength ◽  
Concrete Cover ◽  
Impact Factors ◽  
Element Analysis ◽  
Strength Concrete ◽  
Strength Grade ◽  
Steel Strength

In order to verify the feasibility of ABAQUS, finite element simulation analysis is used to a castellated steel reinforced high strength concrete beam (CSRHSC beam) firstly. Then we consider the strength of steel, strength grade of concrete and thickness of steel protective layer as parameters to study the mechanical properties of the beam by ABAQUS. The results show that: The bearing capacity of beam increases when the steel strength improves, but the magnitude of increase will gradually reduce with the increase of steel strength. Along with the strength grade of concrete increase, the yield strength and ultimate strength basically tend to linear increasing, the ductility tend to decreasing. With the increase of thickness of concrete cover, the ductility of the beam improves but the ultimate strength decreases.

Study on Strength Development of High Strength Concrete Containing Alccofine and Fly-Ash

2012 ◽  
Vol 2 (3) ◽  
pp. 102-104 ◽  
Author(s):  
Suthar Sunil B ◽  
◽  
Dr. (Smt.) B. K. Shah Dr. (Smt.) B. K. Shah
Keyword(s):  
Fly Ash ◽  
High Strength Concrete ◽  
High Strength ◽  
Strength Development ◽  
Strength Concrete
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