FLEXURAL BEHAVIOR OF HYBRID REINFORCED CONCRETE BEAMS COMBINING ULTRA HIGH STRENGTH CONCRETE AND PORECILENITE AGGREGATE LIGHTWEIGHT CONCRETE

Abstract: High Strength Concrete is an alternative construction material for supporting heavy loads. High strength concrete is a brittle material that susceptible to crack. One of the concrete repairing method is epoxy injection. The aim of this study is to determine the flexural behavior of high strength reinforced concrete beams after cracking and repaired with the Epoxy Injection. This study used 4 (four) high strength reinforced concrete beams (BBMT) with (15 ´ 30 ´ 220) cm dimention. One of the beam is for comparison (BBMT Normal) and 3 (three) other beams were tested at the age 7 days (BBMT E-7), 14 days (BBMT E-14) and 28 days (BBMT E-28) after repaired. The beams is designed to have flexural failure by using a compression reinforcement and shear reinforcement of 11.9 mm and 15.8 mm for tensile reinforcement. The water cement ratio for mix design is 0,25 obtained at 28 days is 66,62 MPa. The results shows that all the beams have flexural failure in agreement to the early design. The ultimate load of BBMT Normal is 17,65 ton with deflection equal to 10,36 mm. Based on theoretical calculation the load is 16.04 tons and deflection 14.38 mm. BBMT E-7 after epoxy injection ultimate load is 20,89 tons and deflection is 41.99 mm. BBMT E-14 ultimate load 21,79 tons and deflection equal to 44,27 mm. The ultimate load of BBMT E-28 is 25.52 tons and deflection 13.49 tons. The increase of load are 18.36%, 23.46% and 44.59% when compared with BBMT Normal. Based on the observation on the BBMT after epoxy injection, no cracks evident in most of the injected areas, new cracks appearing around the area of initial crack. It is concluded that epoxy injection is capable to increase the capacity of repaired high strength concrete and th flexural strength of the epoxy repaired concrete beams is increase as the age increased. Abstrak: Beton mutu tinggi merupakan salah satu alternatif material konstruksi untuk pembebanan besar. Beton mutu tinggi memiliki sifat yang kaku sehingga rentan terhadap retak. Salah satu metode perbaikan pada retak beton yaitu injeksi epoxy. Penelitian ini dilakukan dengan tujuan untuk mengamati perilaku lentur pada balok beton bertulang mutu tinggi yang diperbaiki dengan injeksi epoxy. Penelitian ini menggunakan 4 (empat) buah benda uji yaitu balok Beton Bertulang Mutu Tinggi (BBMT) dengan ukuran (15 ´ 30 ´ 220) cm. Benda uji pertama sebagai pembanding (BBMT Normal) dan 3 (tiga) benda uji lain diuji sesuai dengan umur perbaikan betonnya yaitu BBMT E-7 (7 hari), BBMT E-14 (14 hari) dan BBMT E-28 (28 hari). Balok didesain mengalami gagal lentur dengan menggunakan tulangan tekan dan tulangan geser berdiameter 11,9 mm ulir serta tulangan tarik 15,8 mm ulir. Kuat tekan beton mutu tinggi yang didapat dari benda uji kontrol kubus sebesar 66,62 MPa dengan FAS 0,25. Hasil penelitian menunjukkan bahwa semua benda uji balok mengalami gagal lentur sesuai dengan desain awal. Beban maksimum yang mampu dicapai oleh balok BBMT Normal adalah 17,65 ton dengan lendutan sebesar 10,36 mm. Perhitungan teoritis beban BBMT Normal yaitu 16,04 ton dan lendutan 14,38 mm. BBMT E-7 setelah diinjeksi menghasilkan beban sebesar 20,89 ton dan lendutan 41,99 mm. Pada BBMT E-14 beban yang dicapai 21,79 ton dan lendutan sebesar 44,27 mm. Beban maksimum pada BBMT E-28 yaitu 25,52 ton dan lendutan 13,49 ton. Masing-masing persentase peningkatan beban jika dibandingkan dengan BBMT Normal adalah 18,36%, 23,46% dan 44,59%. Pola retak yang terjadi pada balok BBMT setelah diinjeksi menunjukkan bahwa tidak terjadi retak pada sebagian besar daerah yang diinjeksi, retak baru muncul di sekitar retak awal. Dapat disimpulkan bahwa injeksi epoxy mampu meningkatkan kapasitas beton mutu tinggi dan umur perbaikan beton mempengaruhi nilai beban maksimum yang mampu dicapai oleh beton.

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Shear Capacity of Reinforced Concrete Beams Using High-Strength Concrete

ACI Journal Proceedings ◽

10.14359/10432 ◽

1986 ◽

Vol 83 (2) ◽

Cited By ~ 7

Keyword(s):

Reinforced Concrete ◽

High Strength Concrete ◽

Concrete Beams ◽

High Strength ◽

Shear Capacity ◽

Reinforced Concrete Beams ◽

Strength Concrete

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Effects of Using High-strength Concrete on Flexural Ductility of Reinforced Concrete Beams

HKIE Transactions ◽

10.1080/1023697x.2002.10667863 ◽

2002 ◽

Vol 9 (1) ◽

pp. 14-21

Author(s):

J C M Ho ◽

A K H Kwan ◽

H J Pam

Keyword(s):

Reinforced Concrete ◽

High Strength Concrete ◽

Concrete Beams ◽

High Strength ◽

Reinforced Concrete Beams ◽

Strength Concrete ◽

Flexural Ductility

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Shear Ductility of Reinforced Concrete Beams of Normal and High-Strength Concrete

ACI Structural Journal ◽

10.14359/4592 ◽

1994 ◽

Vol 91 (2) ◽

Cited By ~ 7

Keyword(s):

Reinforced Concrete ◽

High Strength Concrete ◽

Concrete Beams ◽

High Strength ◽

Reinforced Concrete Beams ◽

Strength Concrete

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Numerical analysis of inelastic reinforced high-strength concrete beams with low reinforcement ratio

Budownictwo i Architektura ◽

10.35784/bud-arch.2331 ◽

2009 ◽

Vol 4 (1) ◽

pp. 005-030

Author(s):

Piotr Smarzewski

Keyword(s):

High Strength Concrete ◽

Concrete Beams ◽

Constitutive Models ◽

High Strength ◽

Structural Materials ◽

Reinforcement Ratio ◽

Reinforced Concrete Beams ◽

Flexural Behavior ◽

Element Analysis ◽

Strength Concrete

Numerical modelling of flexural behavior of the reinforced highstrength concrete beams with low reinforcement ratio is discussed in this paper. Modelling mechanism of failure reinforced concrete beams under static load, static deformation processes of the reinforced high-strength concrete beams with regard to the physical nonlinearities of the structural materials (i.e. concrete and reinforcement steel) were developed using finite element analysis. The comparison of the numerical and experimental results as well as theoretical solutions, were presented. The compared results indicate correctness of the constitutive models of the structural materials: concrete and reinforcing steel and effectiveness of the solution method.

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High Strength Concrete Beams Reinforced with Hooked Steel Fibers under Pure Torsion

Civil Engineering Journal ◽

10.28991/cej-2022-08-01-07 ◽

2022 ◽

Vol 8 (1) ◽

pp. 92-104

Author(s):

Haleem K. Hussain ◽

Mustafa Shareef Zewair ◽

Mazin Abdulimam Ahmed

Keyword(s):

Compressive Strength ◽

Reinforced Concrete ◽

High Strength Concrete ◽

Concrete Beams ◽

Volume Fraction ◽

High Strength ◽

Reinforced Concrete Beams ◽

Pure Torsion ◽

Fiber Volume ◽

Strength Concrete

A study of the behavior of fibers in high-strength reinforced concrete beams is presented in this paper. Twelve reinforced concrete beams were tested under a pure torsion load. Different compressive strengths (45.2, 64.7, and 84.8 MPa) and fiber volume fractions (0, 0.25, 0.5, and 0.75) with variable spacing between transverse reinforcements have been used. It was discovered that the maximum torque of a high-strength concrete beam is increased by about 20.3, 25.6, and 27.1% when the fractional volume of fiber is increased from 0 to 0.25, 0.5 and 0.75 respectively (when the compressive strength is 45.2 MPa and the transverse reinforcement spacing is 100 mm). The test results show that the ultimate torsional strength becomes higher when the concrete compressive strength increases, and this percentage increase becomes higher with increasing steel fiber volume fraction. When the spacing between transverse reinforcements decreases from 150 to 100 mm, the ultimate torque increases by 19.9%. When the spacing between transverse reinforcements decreases from 100 to 60 mm, the ultimate torque increases by 17.0%. In these beams, the fibers’ compressive strength and volume fraction were kept constant at 45.2 MPa and 0.75, respectively. Doi: 10.28991/CEJ-2022-08-01-07 Full Text: PDF

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Finite element analysis of high strength reinforced concrete beams

MATEC Web of Conferences ◽

10.1051/matecconf/201825003007 ◽

2018 ◽

Vol 250 ◽

pp. 03007

Author(s):

CL Oh ◽

SW Lee ◽

MZ Mohd Raizamzamani ◽

AR Azerai ◽

Y Norrul Azmi

Keyword(s):

Finite Element Analysis ◽

Finite Element ◽

Reinforced Concrete ◽

High Strength Concrete ◽

Concrete Beams ◽

Construction Material ◽

High Strength ◽

Reinforced Concrete Beams ◽

Element Analysis ◽

Strength Concrete

Development of high strength concrete as a new ecological construction material to sustain the gradually expanding construction industry has arisen. This paper presents nonlinear finite element analysis of three-dimensional high strength reinforced concrete beams using ABAQUS. The uniaxial compressive strength for the beam models were taken from the existing experimatal data on high strength concrete cubes. Eurocode 2 was also used to establish material parameters for the constitutive models for concrete and reinforcing bars. In this study, two 150mm x 200mm x 1200mm simply supported rectangular concrete beam models subjected to loads at different shear span to effective depth ratios (a/d = 1.0 and 2.0) were analysed. Numerical results were validated with the existing experimental data specifically on the load-deflection responses and von mises stresses. It was found that the finite element results show greater than 70% agreement with the experimental results.

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A Comparative Experimental Study on the Flexural Behavior of High-Strength Fiber-Reinforced Concrete and High-Strength Concrete Beams

Advances in Materials Science and Engineering ◽

10.1155/2018/7390798 ◽

2018 ◽

Vol 2018 ◽

pp. 1-13 ◽

Cited By ~ 6

Author(s):

In-Hwan Yang ◽

Changbin Joh ◽

Kyoung-Chul Kim

Keyword(s):

Reinforced Concrete ◽

High Strength Concrete ◽

Concrete Beams ◽

High Strength ◽

Fiber Reinforced Concrete ◽

Flexural Behavior ◽

Flexural Toughness ◽

Strength Concrete ◽

Ductility Index ◽

High Strength Fiber

The flexural responses of high-strength fiber-reinforced concrete (HSFRC) beams and high-strength concrete (HSC) beams are compared in this study. A series of HSFRC and HSC beams were tested under pure flexural loading. The effects of the type of concrete, compressive strength of the concrete, and tensile rebar ratio on the flexural behavior of the concrete beams were investigated. The flexural behavior of the HSFRC and HSC beams including the induced crack and failure patterns, load and deflection capacity, crack stiffness, ductility index, and flexural toughness was compared. The crack stiffness of the HSC and HSFRC beams increased with the rebar ratio. For the same rebar ratios, the crack stiffness of the HSFRC beams was much greater than that of the HSC beams. The ductility index of the HSC beams decreased sharply with an increase in the rebar ratio, but the ductility index of the HSFRC beams did not show a clear decrease with increasing rebar ratio. The flexural toughness of the HSFRC beams was greater than that of the HSC beams at higher rebar ratios of 1.47% and 1.97%, indicating that the energy absorption of the HSFRC beams was greater than that of the HSC beams. Test results also indicated that HSFRC developed better and more consistent ductility with higher rebar ratio. In addition, the tested bending strength and sectional analysis results were compared.

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