Repaired Reinforced Concrete Beams with Normal and High Strength Concrete

2013 ◽  
Vol 6 (2) ◽  
pp. 21-37
Author(s):  
Emad Yassin Khudhair
Keyword(s):  
Reinforced Concrete ◽  
High Strength Concrete ◽  
High Strength ◽  
Fiber Reinforced Concrete ◽  
Reinforced Concrete Beams ◽  
Wire Mesh ◽  
Strength Concrete ◽  
Strength And Deformation ◽  
Normal Strength ◽  
Concrete Elements

In resent years several attempts were undertaken to repair damaged reinforced concrete structures. Studies on the effectiveness of repaired and strengthened reinforced concrete elements which fail primarily due to formation of major flexural cracks are same what limited for normal strength concrete (NSC) and very limited for high strength concrete (HSC). The overall objective of the present work is to investigate the strength and deformation characteristics in flexure of reinforced HSC and NSC beams repaired with either with concrete alone or with fiber reinforced concrete or with Welded Wire Mesh (W.W.M). From the results obtained, it was found that the beams were adequately repaired and the general mode of failure was flexural. The repaired beams had higher strength than the original beams. All repaired beams exhibited significant decrease in deflection than the original beams.

Flexural and Shear Capacity Evaluation of Reinforced Ultra-High Strength Concrete Members with Steel Rebars

2013 ◽  
Vol 577-578 ◽  
pp. 17-20 ◽  
Author(s):  
Baek Il Bae ◽  
Hyun Ki Choi ◽  
Chang Sik Choi
Keyword(s):  
High Strength Concrete ◽  
Steel Fiber ◽  
Concrete Beams ◽  
High Strength ◽  
Fiber Reinforced Concrete ◽  
Reinforced Concrete Beams ◽  
Steel Fiber Reinforced Concrete ◽  
Strength Concrete ◽  
Ultra High Strength Steel ◽  
Normal Strength

High-strength concrete is widely used in construction field. The growth has been possible as a result of recent developments in material technology and a demand for high-strength concrete. High-strength concrete has different mechanical properties from normal-strength, as many researches mentioned about. However, the existing equations and procedures for prediction of ultra-high strength concrete are based on tests using normal-strength concrete, yet. In this study, experiments on ultra-high-strength steel fiber reinforced concrete beams with 2% volume fraction of steel fiber and 200MPa of compressive strength have been conducted. Test was conducted by two point loading with 2,000kN actuator for slender test specimen which have varied shear-span to depth ratio. Using test results with several assumptions, an empirical equation for flexural strength and shear strength of ultra-high-strength steel fiber reinforced concrete beams have been proposed.

scholarly journals LIGHTER HIGH STRENGTH CONCRETE BEAM

2019 ◽  
Vol 2 (2) ◽  
pp. 17-26
Author(s):  
Nuri Mohamed Elbasha
Keyword(s):  
High Strength Concrete ◽  
Construction Projects ◽  
High Strength ◽  
Reinforced Concrete Beams ◽  
Limited Information ◽  
Experimental Proof ◽  
Strength Concrete ◽  
Project Costs ◽  
Normal Strength ◽  
The Cost

High strength concrete (HSC) has been used extensively in civil construction projects worldwide because it reduces the cross section and the weight of long construction members. In recent years a marked increase in the use of High Strength Concrete (HSC) has been evident in Australian building construction despite the fact that the current Australian design standard provides no design rules for such a material. Very limited information on the properties of HSC and its design and construction processes are available in Australia, although in recent times many studies have been undertaken to produce material and, more importantly, to determine its characteristic. In the last 20 years there has been extensive research to economically utilize new components to improve the quality of HSC. HSC produces smaller but stronger structural elements with large spaces available. It has been studied that the cost of using HSC instead of Normal Strength Concerete (NSC) in different types of constructions. This proved that structures constructed with HSC are lighter and economical compared with those constructed with NSC. In the long term durability significantly affects project costs. In other words after several years a concrete structure needs rehabilitation or in critical cases must be demolished, therefore the price of a project consists of initial costs plus those covering any rehabilitation. A huge amount of money could be saved by utilizing the durability characteristics of high strength concrete. This study presents recent information and the benefits of high strength concrete. Also, provides in brief an experimental proof that installing a helix with a suitable pitch and diameter in the compression zone of beams significantly enhances their strength and ductility. Therefore, designers could confidently use high-strength concrete and helical confinement to design long and light reinforced concrete beams.

scholarly journals Effect of size and shape of specimen on compressive strength of glass fiber reinforced concrete (GFRC)

2011 ◽  
Vol 9 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Rao Krishna ◽  
Rathish Kumar ◽  
B. Srinivas
Keyword(s):  
Compressive Strength ◽  
Reinforced Concrete ◽  
Glass Fiber ◽  
High Strength Concrete ◽  
High Strength ◽  
Fiber Reinforced Concrete ◽  
Strength Concrete ◽  
Size And Shape ◽  
Glass Fiber Reinforced ◽  
Compressive Strength Of Concrete

Concrete is a versatile material with tremendous applications in civil engineering construction. Structural concrete elements are generally made with concrete having a compressive strength of 20 to 35 MPa. Lately, there is an increase in use of high strength concrete (HSC) in major construction projects such as high-rise buildings, and bridges involving members of different sizes and shapes. The compressive strength of concrete is used as the most basic and important material property in the design of reinforced concrete structures. It has become a problem to use this value as the control specimen sizes and shapes are different from country to country. In India, the characteristic compressive strength is usually measured based on 150 mm cubes [1]. But, the ACI code of practice specifies the design compressive strength based on the standard 150x300 mm cylinders [2]. The use of 100x200 mm cylinders gained more acceptance as the need to test high strength concrete increases [3]. In this context the size and shape of concrete becomes an important parameter for the compressive strength. In view of the significance of compressive strength of concrete and due to the fact that the structural elements of different sizes and shapes are used, it is proposed to investigate the effect of size and shape of the specimen on the compressive strength of concrete. In this work, specimens of plain as well as Glass Fiber Reinforced Concrete (GFRC) specimens are cast in order to carry out a comparative study.

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