Effect of Concrete Compressive Strength on Performance of Fibrous Reinforced Concrete Corbels

Author(s):  
Aamer Najim Abbas ◽  
2020 ◽  
pp. 002199832097373
Author(s):  
Fares Jnaid

This paper investigates the effects of different parameters on the live load carrying capacity of concrete beams reinforced with FRP bars. The author performed a parametric study utilizing an innovative numerical approach to inspect the effects of multiple variables such as reinforcement ratio, concrete compressive strength, span to depth ratio, FRP type, and bar diameter on load carrying capacity of FRP reinforced concrete beams. This study concluded that unless the span to height ratio is smaller than 8, tension-controlled sections are impractical as they do not meet code requirements for serviceability. In addition, it is recommended to use higher reinforcement ratios when using larger span to depth ratios and/or when using CFRP reinforcing bars. Moreover, larger number of bars with small diameter is more practical than fewer large diameter bars. Furthermore, this research suggests that increasing the concrete compressive strength is associated with a significant increase in the ultimate flexural capacity of FRP reinforced beams.


2013 ◽  
Vol 351-352 ◽  
pp. 422-426
Author(s):  
Yong Ping Xie ◽  
Lei Jia ◽  
Gang Sun

With the development of modern constructional technique, more attention on the size effect is paid by academics and engineers. The normal section bearing capacity of Reinforced Concrete Column is analyzed by eccentrically compressed theory firstly. The size effect on normal section bearing capacity of reinforced concrete column is obtained by theoretical analysis and experimental summary. The size effect formula of concrete compressive strength is proposed. Finally, a research thinking of size effect on bearing capacity is suggested.


2017 ◽  
Vol 3 (10) ◽  
pp. 929
Author(s):  
Mohannad Husain Al-Sherrawi ◽  
Hamza M. Salman

No attempts have been made in developing the N-M interaction diagram for reinforced concrete columns strengthened with steel jackets using the plastic stress distribution method. Therefore, this paper presents an analytical model to construct the N-M interaction diagram for reinforced concrete columns strengthened with steel jackets using the plastic stress distribution method after assuming the behavior of strengthened column to be like composite column and including the effects of confinement on concrete compressive strength. The proposed model was compared with experimental results. The comparisons showed that the model is conservative and it reveals the ultimate strength of the strengthened column. A parametric study has been also carried out to investigate the influence of various parameters on the N-M interaction diagram of the strengthened column. These parameters were: dimensions of steel angle, yield stress of the steel angles, concrete compressive strength and the size of the reinforcement bars used in RC columns. The results made clear the effects of these parameters on the N-M interaction diagram, and encouraged the use of the model in preliminary strengthening studies.


2021 ◽  
Vol 261 ◽  
pp. 02019
Author(s):  
Tu-Sheng He ◽  
Meng-Qian Xie ◽  
Yang Liu ◽  
San-Yin Zhao ◽  
Zai-Bo Li

The influence of steel fiber and polypropylene fiber mixed on compressive strength of high performance concrete (HPC) was studied. The steel fiber content (0.5%, 1.0%, 1.5%, 2.0%) (volume fraction, the same below), polypropylene fiber content (0.05%, 0.1%, 0.15%, 0.2%) and length (5mm, 6.5mm, 12mm, 18mm) were studied by L16 (45) orthogonal test for 28d ages, the range analysis and variance analysis of the test results are carried out, and the prediction model of compressive strength of hybrid fiber reinforced concrete was established. The results show that: The significant influence factor of concrete compressive strength is the volume fraction of polypropylene fiber, while the length of polypropylene fiber and the volume fraction of steel fiber are not significant; the concrete compressive strength with polypropylene fiber shows negative hybrid effect; The prediction model of compressive strength of hybrid fiber reinforced concrete has high accuracy, and the average relative errors is 2.96%.


2020 ◽  
Vol 38 (7A) ◽  
pp. 1034-1046
Author(s):  
Ali ِA. Abdulsada ◽  
Raid I. Khalel ◽  
Kaiss F. Sarsam

The requirements of minimum flexural reinforcement in the last decades have been a reason for controversy. The structural behavior of beams in bending is the best way of investigating and evaluating the minimum reinforcement in flexure. For this purpose, twelve singly reinforced concrete beams with a rectangular cross-section of (125 mm) width by (250 mm) height and (1800 mm) length were cast and tested under two-point loads up to failure. These beams were divided into three groups with different compressive strengths (25, 50, and 80 MPa). Each group consists of four beams with different amounts of tension steel reinforcement approximately equal to (0% Asmin, 50% Asmin, 100% Asmin and 150% Asmin), two bar diameters (Ø6 mm and Ø8 mm) were used as the longitudinal tension reinforcement with different yield and ultimate strengths, the minimum amount of reinforcement required is calculated based on ACI 318M-2014 code. The results show that for the reinforced concrete beams, the flexural reinforcement in NSC beams increases the first cracking load and the increment increased with an increasing amount of reinforcement, while for HSC beams the increasing in first cracking load are very little when the quantity of reinforcement less than the minimum flexural reinforcement and increased with the increasing amount above the minimum flexural reinforcement. The equation of ACI 318M-14 code gives adequate minimum flexural reinforcement for NSC and overestimate value for HSC up to (83 MPa), A new formula is proposed for HSC rectangular beams up to (90 MPa) concrete compressive strength by reducing the equation of ACI 318M-14 code for minimum flexural reinforcement by a factor depending on concrete compressive strength.  


2007 ◽  
Vol 34 (4) ◽  
pp. 565-575 ◽  
Author(s):  
Gerson Moacyr Sisniegas Alva ◽  
Ana Lúcia Homce de Cresce El Debs ◽  
Mounir Khalil El Debs

Beam-column joints are considered critical regions within the structural system — especially under seismic loading — requiring careful design. Results from tests on four exterior reinforced concrete (RC) beam-column subassemblages are presented in this paper as part of an experimental investigation on the behaviour of RC beam-column connections under reversal cyclic loading. The influence of joint transverse reinforcement rate and concrete compressive strength on the RC beam-column connection behaviour was investigated. It is concluded that concrete compressive strength is the major factor that governs the joint shear capacity. The experimental results also indicated that joint transverse reinforcement affects the load-displacement response of such connections.Key words: cyclic loading, seismic analysis, reinforced concrete structures, beam-column connection.


Author(s):  
Payal Sachdeva ◽  
A.B. Danie Roy ◽  
Naveen Kwatra

Headed bars (HB) with different head shapes (Square, Circular, and Rectangular) and bar diameters (db: 16, 20, and 25 mm) embedded in steel fiber reinforced concrete have been subjected to pull-out test. The influence of head shapes, concrete compressive strength (M20 and M40), db, and steel fibers (0, 0.5, 1, and 1.5%) on the anchorage capacity of HB have been evaluated. Numerical model for improving the anchorage capacity of HB has also been proposed. Results have revealed that the anchorage capacity of HB increases with the increase in concrete compressive strength, db, and steel fibers, which have been validated by non-linear regression analysis using dummy variables. Two failure modes namely, steel and concrete-blowout have been observed and the prevailing mode of failure is steel failure. Based on load-deflection curves and derived descriptive equations, it is observed that the circular HB has displayed the highest peak load.


Author(s):  
S. A. Solov’ev ◽  
O. V. Yarygina

The article describes a probabilistic approach to the reliability analysis of a flexural reinforced concrete element by the cracking criterion using the provisions of fracture mechanics. Two mathematical models of limit state are proposed for reliability analysis: with the evaluation of the critical stress intensity coefficient directly and through the design concrete compressive strength. On the basis of regression analysis, the relationship between the critical stress intensity coefficient and the design concrete compressive strength is established which can be used in the inspection of reinforced concrete structural elements. The influence of the design concrete compressive strength on the failure (cracking) probability of the flexural reinforced concrete element is analyzed. The numerical example of reliability analysis is given for the reinforced concrete beam by the criterion of cracking. It is noted that the required level of reliability should be set for each structural object individually based on the acceptable risk value using economic and non-economic losses.


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