scholarly journals Comparative Study of Structural Behaviour for Rolled and Castellated Steel Beams with Different Strengthening Techniques

2019 ◽  
Vol 5 (6) ◽  
pp. 1384-1394
Author(s):  
Shakir Mahmood Hadeed ◽  
Ahmad Jabbar Hussain Alshimmeri
Keyword(s):  
High Strength Concrete ◽  
Reference Beam ◽  
Construction Materials ◽  
High Strength ◽  
Steel Beams ◽  
Steel Beam ◽  
Structural Behaviour ◽  
Element Analysis ◽  
Strength Concrete ◽  
Structural Applications

Currently, the castellated steel beams are used widely because of their useful structural applications and serviceable performance due to their good significant properties such as light weight, facility in construction, materials economize and strength. The castellated steel beam fabricated from its origin solid beam (I-beam) by cutting its web in a zigzag path and then re-joined the two halve by welding so the height of the castellated beam expanded about 50%. The aim of this paper is to study the effect of castellation with and without strengthening on the structural behaviour of castellated beams and compare the results with the origin solid steel beam. Three castellated beams with deferent configuration in addition to solid beam subjected to two equal point loads at mid third of span with simple support condition were analysed numerically using finite element analysis by Abaqus software virgin (6.14.5) .The results show that the load carrying capacity values of castellated steel beams that represent (second, third& fourth) models were increased by (39.11,105.95&124.77) % respectively compared with origin solid beam  due to increase beams stiffness after castellation and strengthening process, while mid-span deflection values at service load were decreased by (36.36,9.10&27.27) % respectively comparing with the origin solid steel beam due to increasing section dimensions and stiffness after castellation process and using strengthening technique respectively. Also it was seen that the maximum ultimate moment and ductility were observed in the fourth model that strengthened by high strength concrete and lacing reinforcement so they increased by 124.79% and 165.65% respectively as compare to reference beam, while the third model that strengthened by high strength concrete was stiffer than other beams.

scholarly journals High Strength Concrete Small Hollow Blocks Made with Rock Chips as Aggregates

2012 ◽  
Vol 5 ◽  
pp. 333-338
Author(s):  
Yong Quan Zhang ◽  
Jie Yuan ◽  
Yong Ge
Keyword(s):  
Compressive Strength ◽  
Solid Waste ◽  
High Strength Concrete ◽  
Construction Materials ◽  
High Strength ◽  
Masonry Structure ◽  
Strength Concrete ◽  
Industrial Solid Waste ◽  
Structural Applications ◽  
Curing Methods

It is more and more general of using industrial solid waste as the aggregates in construction materials for non-structural applications. But because of the developments and applications of reinforced blocks masonry structure in the modern masonry structure, especially in the mid-high and high storey buildings, there will be a growing interest of using industrial solid waste to produce high strength concrete small hollow blocks for structural applications. This experiment by mixing the different proportions of rock chips within the range of 30-70% as the replacement for sand prepared high strength concrete small hollow blocks which the compressive grade is MU 15.0, the influence of aggregates grading on the compressive strength of high strength concrete small hollow blocks was investigated at the same water/cement (w/c) ratio (0.45). In addition, the influence of the different curing methods on the compressive strength and shrinkage of high strength concrete small hollow blocks were also investigated, test results showed that high strength concrete small hollow blocks under the curing method which is the one-time pouring the ample amount of water, covered and sealed with plastic sheeting, the compressive strength had a better development, and the total shrinkage was larger than others.

scholarly journals Effect of basalt fibres on the parameters of fracture mechanics of MB modifier based high-strength concrete

2018 ◽  
Vol 251 ◽  
pp. 02003 ◽  
Author(s):  
Makhmud Kharun ◽  
Dmitry Koroteev
Keyword(s):  
Compressive Strength ◽  
Fracture Mechanics ◽  
High Strength Concrete ◽  
High Strength ◽  
Critical Energy ◽  
Critical Stress Intensity Factor ◽  
Critical Energy Release Rate ◽  
Environmental Friendliness ◽  
Strength Concrete ◽  
Structural Applications

Basalt fibres (BF) are increasingly studied in structural applications due to its environmental friendliness and good mechanical properties. Mass production of high-strength concrete (HSC) in Russia is mainly associated with the use of organomineral modifiers of the MB series, containing in their composition microsilica, fly ash, hardening regulator and superplasticizer C-3 in different ratios. In our study we produced HSC specimens (without BF, and with 1 wt.% chopped BF) using the modifier MB10-30, with the dimensions of 100x100x100 mm, 100x100x400 mm, 100x100x400 mm with the artificial crack of 25 mm deep in the middle of the span, and also 100х75х400 mm (75 mm height was taken equal to the height of the section above the crack of the 2nd type of prisms). The compressive strength, the tensile strength at bending, the strength at axial tension, the cracking moment, and also the parameters of fracture mechanics, such as: the critical stress intensity factor and the critical energy release rate, at the curing periods of 7, 14, 28, 60 days, have been determined. We also evaluated the influence of crack in the bend element on the value of the cracking moment. The results showed that the inclusion of BF in MB modifier based HSC resulted in a decrease in the compressive strength, however, significantly enhanced its flexure behavior.

Performance of high strength concrete-filled steel columns exposed to fire

1998 ◽  
Vol 25 (6) ◽  
pp. 975-981 ◽  
Author(s):  
VKR Kodur
Keyword(s):  
Fire Resistance ◽  
High Strength Concrete ◽  
High Strength ◽  
Experimental Program ◽  
Structural Behaviour ◽  
Steel Columns ◽  
Strength Concrete ◽  
Normal Strength ◽  
Concrete Filling ◽  
Hollow Structural Section

Results from an experimental program on the behaviour of high strength concrete-filled steel hollow structural section (HSS) columns will be presented for three types of concrete filling. A comparison will be made of the fire-resistance performance of HSS columns filled with normal strength concrete, high strength concrete, and steel-fibre-reinforced high strength concrete. The various factors that influence the structural behaviour of high strength concrete-filled HSS columns under fire conditions are discussed. It is demonstrated that, in many cases, addition of steel fibres into high strength concrete improves the fire resistance and offers an economical solution for fire-safe construction.Key words: high strength concrete, steel columns, fire-resistance design, high-temperature behaviour, concrete-filled steel columns.

scholarly journals Dynamic displacement analysis of reinforced concrete deep beams made of high strength concrete. Part II: Dynamic displacement analysis of reinforced concrete deep beams made of high strength C200 grade concrete

2018 ◽  
Vol 67 (2) ◽  
pp. 25-48
Author(s):  
Waldemar Cichorski
Keyword(s):  
Reinforced Concrete ◽  
Dynamic Load ◽  
High Strength Concrete ◽  
Construction Materials ◽  
High Strength ◽  
Deep Beam ◽  
Deep Beams ◽  
Dynamic Displacement ◽  
Displacement Analysis ◽  
Strength Concrete

The dynamic load displacements were analysed of rectangular concrete deep beams made of very high strength concrete, grade C200, including an evaluation of the physical non-linearity of the construction materials: concrete and reinforcing steel. The analysis was conducted using the method presented in [1]. The numerical calculation results are presented with particular reference to the displacement state of rectangular concrete deep beams. A comparative analysis was conducted on the effect of the high-strength concrete and the steel of increased strength on a class C200 concrete deep beam versus the results produced in [10] for a class C100 concrete deep beam. Keywords: mechanics of structures, reinforced concrete structures, deep beams, dynamic load, physical non-linearity

scholarly journals Lightweight high-strength concrete with the use of waste cenosphere as fine aggregate

2019 ◽  
Vol 24 (4) ◽  
Author(s):  
Felipe Basquiroto de Souza ◽  
Oscar Rubem Klegues Montedo ◽  
Rosielen Leopoldo Grassi ◽  
Elaine Gugliemi Pavei Antunes
Keyword(s):  
High Strength Concrete ◽  
Power Plants ◽  
Lightweight Concrete ◽  
Construction Materials ◽  
Hollow Structure ◽  
High Strength ◽  
Cementitious Materials ◽  
Partial Substitution ◽  
Fine Aggregate ◽  
Strength Concrete

ABSTRACT Cenosphere is a coal combustion by-product that presents interesting properties to be used in the production of cementitious materials, such as hollow structure, low density, low thermal conductivity and notably thermal stability. In addition, it displays pozzolanic reactivity under thermal curing. However, the cenosphere potential for the development of unique construction materials has not been fully investigated, remaining obscure for both power plants and the construction field. This study investigated the employment of waste cenosphere in partial substitution to sand for the obtainment of high-strength lightweight concrete materials. Cenosphere from a Brazilian power plant was chemically and physically characterized and the feasibility of its use in concretes was investigated. It was discovered that the power plant’s fly ash is composed of approximately 0.2% of cenosphere. In addition, the cenosphere displayed size ranging from 30 to 300 µm and were suitable for use as fine aggregate in concrete. Concrete with 33, 67, and 100% fine aggregate replacement by the waste cenosphere was produced. Cenosphere-based high strength concrete presented strength higher than 70 MPa and density as low as 1500 kg • m-3. Compared to mixes of reference, cenosphere application as fine aggregate improved the specific strength of high-strength concrete while maintaining equivalent mechanical properties.

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