Size Effect on the Bond Behavior of Grouted Reinforcing Bars Embedded in Light-weight Concrete

2021 ◽  
Author(s):  
Aamer Abbas ◽  
◽  
Yaqoob Yaqoob ◽  
Ola Hussein ◽  
Ibrahim Al-Ani ◽  
...  
Keyword(s):  
Bond Strength ◽  
Concrete Specimen ◽  
Light Weight ◽  
Reinforcing Bars ◽  
Conventional Concrete ◽  
Bond Behavior ◽  
Pull Out ◽  
Specimen Width ◽  
Light Weight Concrete ◽  
The Relationship

This study presents experimentally the bond behavior of light-weight concrete specimens with grouted reinforcing bars in comparison with conventional concrete specimens. A total of (9) pull-out specimens were studied; (3) specimens of conventional concrete, (3) specimens of light-weight concrete, and other (3) specimens of grouted light-weight concrete. Two variables are adopted in this investigation: specimen width and type of concrete (conventional concrete, light-weight concrete and grouted light-weight concrete). The study contains a discussion of the general behavior of the specimens in addition to the study of the ultimate bond capacity, maximum bond stresses and the relationship between the stress and the slip for different pull-out specimens. Results show that bond strength is highest for the largest specimen size (bond strength of grouted light-weight concrete specimen with specimen width 400 mm is higher than that of the specimen with (200 mm) width by about (13.13%)). Also, bond strength is highest for the grouted light-weight concrete specimen (bond strength of grouted light-weight concrete specimen is higher than conventional concrete specimen by (11.11%)).

scholarly journals The Comparison of Bond Strength between Geopolymer Concrete and OPC Concrete for Plain Reinforcing Bars

2018 ◽  
Vol 159 ◽  
pp. 01017 ◽  
Author(s):  
Nuroji ◽  
Daniel Herdian Primadyas ◽  
Ilham Nurhuda ◽  
Muslikh
Keyword(s):  
Bond Strength ◽  
Geopolymer Concrete ◽  
Test Results ◽  
Reinforcing Bars ◽  
Normal Concrete ◽  
Steam Power ◽  
Bond Behavior ◽  
Pull Out ◽  
Concrete Blocks ◽  
Class F Fly Ash

This paper describes the research on bond behavior of plain reinforcing bars in geopolymer and normal concrete. The geopolymer concrete in this research was made of class F fly ash taken from Tanjung Jati Electric Steam Power Plant (PLTU) with Sodium Hydroxide (NaOH) and Sodium Silicate (Na2SiO3) as alkaline activator, added in the mixture. The effect of bar size was studied by varying the bar diameter in range 10 mm to 19 mm. Each bar was casted in the center of concrete blocks made of geopolymer as well as normal concrete. Pull-out tests were carried out to the specimens that have reached 28 days of age. The test results show that the bond behavior of geopolymer concrete differs substantially from normal concrete, where geopolymer concrete has a higher bond strength when compared to normal concrete with identical concrete strengths.

scholarly journals BOND STRENGTH OF LIGHT-WEIGHT CONCRETE PULL-OUT SPECIMENS CONTAIN STEEL FIBERS

2018 ◽  
Vol 22 (02) ◽  
pp. 123-133
Author(s):  
Aamer Najim Abbas ◽  
◽  
Lina Abdulsalam Shihab ◽  
Yaqoob Talib Yaqoob ◽  
◽  
...  
Keyword(s):  
Bond Strength ◽  
Steel Fibers ◽  
Light Weight ◽  
Pull Out ◽  
Light Weight Concrete

scholarly journals Study on Behaviour of Cellular Concrete Slab

2018 ◽  
Vol 7 (2.12) ◽  
pp. 420
Author(s):  
Sindhu Nachiar S ◽  
Anandh S ◽  
Jeyem Veerarajan
Keyword(s):  
Concrete Slab ◽  
Single Point ◽  
Void Volume ◽  
Light Weight ◽  
Test Results ◽  
Structural Elements ◽  
Conventional Concrete ◽  
Air Voids ◽  
Construction Techniques ◽  
Light Weight Concrete

Generally for any construction, normal conventional concrete is used to obtain required strength as per design. In the construction industry, now a day’s many construction techniques are in practice to minimise the self weight of concrete, thereby reducing the size of structural elements. One of the most widely adopting techniques is use of light weight concrete. But use of these light weight concrete do not fulfil the strength requirement as per the design of the structure. Hence it is used only as non-load bearing structural elements in the field. In view of this, in this study the attempt has been made to introduce the air voids in conventional concrete without compromising the strength. In this work the air voids are introduced in the concrete slabs and it is tested in the laboratory to know the performance. For this purpose, the slab of the size of 600mm x 600mm x 100mm is prepared with the voids of diameters 30mm, 35mm and 40mm. The voids are introduced in the concrete slab in four different configurations (line, X, I and matrix) to prepare the cellular elements. The normal and cellular slabs are tested under single point loading and the effect of various configurations is studied at the age of 28 days. From the test results, it was found that the slab with void volume of 1.59% shows the lowest stiffness and the slab with void volume of 2.28% shows the highest stiffness.

Bond strength of glass fibre reinforced polymer reinforcing bars in normal and self-consolidating concrete

2005 ◽  
Vol 32 (3) ◽  
pp. 553-560 ◽  
Author(s):  
M Reza Esfahani ◽  
M Reza Kianoush ◽  
M Lachemi
Keyword(s):  
Bond Strength ◽  
Glass Fibre ◽  
Reinforcing Bars ◽  
Reinforced Polymers ◽  
Self Consolidating Concrete ◽  
Pull Out ◽  
Glass Fibre Reinforced Polymer ◽  
Fibre Reinforced Polymer ◽  
Glass Fibre Reinforced ◽  
Cover Thickness

This paper presents the results of an experimental study on bond strength of reinforcing bars made of glass fibre reinforced polymers (GFRP) embedded in normal and self-consolidating concrete. The study included pull-out tests of 36 GFRP reinforcing bars embedded in concrete specimens. Different parameters such as type of concrete, bar location, and cover thickness were considered as variables in different specimens. The results showed that the type of bond failure was by splitting of concrete for all specimens. The bond strength of bottom GFRP reinforcing bars was almost the same for both normal concrete and self-consolidating concrete. For the top bars, however, the bond strength of self-consolidating concrete was less than that of normal concrete.Key words: bond strength, glass FRP, reinforcing bars, top-bar effect, self-consolidating concrete.

scholarly journals Effect of Fibers on the Bond Behavior of Deformed Steel Bar Embedded in Recycled Aggregate Concrete

2020 ◽  
Vol 39 (4) ◽  
pp. 846-858
Author(s):  
Rashid Hameed ◽  
Usman Akmal ◽  
Qasim S. Khan ◽  
Muhammad Ahsan Cheema ◽  
Muhammad Rizwan Riaz
Keyword(s):  
Compressive Strength ◽  
Concrete Structures ◽  
Steel Fibers ◽  
Recycled Aggregates ◽  
Polypropylene Fibers ◽  
Reinforcing Bars ◽  
Bond Behavior ◽  
Pull Out ◽  
Steel Bar ◽  
Natural Aggregates

A large volume of concrete debris is being produced in many countries on the globe due to the demolition of old concrete structures and testing of concrete specimens in laboratories. One of the ways to reuse concrete debris is to produce Recycled Aggregates (RA) and use them in new concrete. In recent years, Recycled Aggregates Concrete (RAC) has experienced increasing demand in various non-structural and structural applications. In reinforced concrete structures, one of the sources of brittle failure is sudden loss of bond between reinforcing bars and concrete in anchorage zones. Therefore, for the structural application of any new kind of concrete such as fiber reinforced RAC, knowledge of bond characteristics of reinforcing bars embedded in concrete becomes essential for determining the overall structural response under different modes of loading. In this regard, this study experimentally investigated the effect of fibers on the bond stress-slip behavior of deformed steel re-bar embedded in RAC. Concrete mixes having 0, 50 and 100% RAs were prepared with and without the addition of fibers. Two types of fibers were investigated in mono form: hooked-ends steel and polypropylene fibers. The dosage of steel and polypropylene fibers was kept 40 and 4.4 kg/m3, respectively. Axial compression and standard pull-out tests were performed. Test specimens for pull-out test were prepared using deformed steel re-bars of 19mm (#6) diameter. The results of strength tests confirmed that the compressive strength of concrete is decreased by replacing Natural Aggregates (NA) with RAs. For bond behavior of steel re-bar, the results of this study showed that replacement of 50% NA with RAs did not affect the bond response of steel bar, however, 100% replacement of NA with RAs showed detrimental effect on bond stress slip behavior. The results further showed that the addition of both types of fibers made it possible to recover the loss in compressive strength, bond strengths and bond toughness occurred because of replacing NA with RAs. In case of RA concrete mixes containing hooked-ends steel fibers, strength values were found even greater than the strength values of Natural Aggregates Concrete (NAC). From the results of this study, it was found that it is possible to design a structural concrete mix using 100% RAs and steel fibers at relatively low dosage of 40kg/m3.

scholarly journals Bond Behavior of Recycled Fiber Recycled Concrete with Reinforcement after Freeze-Thaw Cycles

Crystals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1506
Author(s):  
Yu Liu ◽  
Jinghai Zhou ◽  
Di Wu ◽  
Tianbei Kang ◽  
Aixia Liu
Keyword(s):  
Bond Strength ◽  
Recycled Concrete ◽  
Recycled Aggregates ◽  
Building Structures ◽  
Two Phase ◽  
Bond Behavior ◽  
Freeze Thaw ◽  
Pull Out ◽  
Recycled Fiber ◽  
Recycled Fibers

Freeze-thaw (F-T) damage is the major factor destroying the bond behavior of reinforced concrete in the cold areas of China. The bond behavior between recycled fiber recycled concrete (RFRC) and reinforcement after F-T cycles was investigated in this paper. The pull-out tests were undertaken with the replacement rate (0, 50%, and 100%) of recycled aggregates (RA) and volume content (0, 0.12%, and 0.24%) of recycled fibers (RFs) as test variables. The results demonstrate that the F-T cycles will reduce the bond strength between RFRC and reinforcement. Bond strength decreases by 69.41% after 150 cycles. Moreover, RF can improve the bond strength between RFRC and reinforcing steel. Bonding strength increases by 11.35% with the addition of 0.12% RF. A simplified two-phase bond-slip model between RFRC and reinforced steel after F-T cycles was eventually established, and it correlated well with the experimental results. This research presents a theoretical basis for the application of RFRC in building structures in cold areas.

scholarly journals Experimental Study of Bond Behavior Between Rebar and PVA-Engineered Cementitious Composite (ECC) Using Pull-Out Tests

2021 ◽  
Vol 8 ◽  
Author(s):  
Jie Xiao ◽  
Xiang Long ◽  
Ming Ye ◽  
Haibo Jiang ◽  
Lingfei Liu ◽  
...  
Keyword(s):  
Bond Strength ◽  
Layer Thickness ◽  
Volume Content ◽  
Cementitious Composite ◽  
Fiber Volume ◽  
Cover Layer ◽  
Bond Behavior ◽  
Engineered Cementitious Composite ◽  
Functional Relationships ◽  
Pull Out

As a novel civil engineering material, Engineered Cementitious Composite (ECC) has attracted more and more attention due to its strain-hardening characteristics, good post-cracking resistance and its unique properties. Bonding between Engineered Cementitious Composite (ECC) and rebar has a great effect on the mechanical behavior of structural members. In this paper, direct pull-out tests were conducted to understand the bond behavior between the ECC and rebar. The test parameters included rebar diameter and type, cover layer thickness, embedment length and fiber volume content. Bond-slip curves, failure and cracking pattern and bond strength were compared and discussed. The test results indicated that the bond strength decreased with the increase of embedded length. Through regression analysis with the test data, the functional relationships between bond strength and cover layer thickness and rebar diameter were fitted well. According to the positive and negative signs of the fitting parameters m and n, the relationship between the bond strength and the cover layer thickness and the rebar diameter could be determined. The bond strength increased obviously with the increase of fiber content. When the fiber volume content was 1, 1.5 and 2%, the bond strength of these specimens were 1.5, 2.5 and 3.1 times that of specimens without polyvinyl alcohol (PVA) fiber.

scholarly journals Bond Strengths of Geopolymer and Cement Concretes

2010 ◽  
Vol 69 ◽  
pp. 143-151 ◽  
Author(s):  
Prabir Sarker
Keyword(s):  
Reinforced Concrete ◽  
Bond Strength ◽  
Concrete Cover ◽  
Reinforced Concrete Structures ◽  
Geopolymer Concrete ◽  
Reinforcing Steel ◽  
Test Results ◽  
Reinforcing Bars ◽  
Pull Out ◽  
Bar Diameter

Geopolymer is an inorganic alumino-silicate product that shows good bonding properties. Geopolymer binders are used together with aggregates to produce geopolymer concrete which is an ideal building material for infrastructures. A by-product material such as fly ash is mixed together with an alkali to produce geopolymer. Current research on geopolymer concrete has shown potential of the material for construction of reinforced concrete structures. Structural performance of reinforced concrete depends on the bond between concrete and the reinforcing steel. Design provisions of reinforced concrete as a composite material are based on the bond strength between concrete and steel. Since geopolymer binder is chemically different from Ordinary Portland Cement (OPC) binder, it is necessary to understand the bond strength between geopolymer concrete and steel reinforcement for its application to reinforced concrete structures. Pull out test is commonly used to evaluate the bond strength between concrete and reinforcing steel. This paper describes the results of the pull out tests carried out to investigate the bond strength between fly ash based geopolymer concrete and steel reinforcing bars. Beam end specimens in accordance with the ASTM Standard A944 were used for the tests. In the experimental program, 24 geopolymer concrete and 24 OPC concrete specimens were tested for pull out. The concrete compressive strength varied from 25 to 55 MPa. The other test parameters were concrete cover and bar diameter. The reinforcing steel was 500 MPa steel deformed bars of 20 mm and 24 mm diameter. The concrete cover to bar diameter ratio varied from 1.71 to 3.62. It was found from the test results that the failure occurred by splitting of concrete in the region bonded with the steel bar, in both geopolymer and OPC concrete specimens. Comparison of the test results shows that geopolymer concrete has higher bond strength than OPC concrete. This suggests that the existing design equations for bond strength of OPC concrete with steel reinforcing bars can be conservatively used for calculation of bond strength of geopolymer concrete.

Experimental Study and Numerical Simulation of Bond Behaviors Between FRP Bar and Concrete

2010 ◽  
Vol 168-170 ◽  
pp. 2134-2138
Author(s):  
Xin Sheng Xu
Keyword(s):  
Bond Strength ◽  
Shear Failure ◽  
Concrete Specimen ◽  
Screw Thread ◽  
Bond Slip ◽  
Pull Out ◽  
Reinforced Polymer ◽  
Steel Bars ◽  
Frp Bar ◽  
Frp Bars

Surface-adhering-sand screw-thread-form FRP bar was produced. By symmetrical pull-out test research to a certain depth in FRP (Fiber Reinforced Polymer) bar concrete, the bond mechanism, the failure mechanism, the bond strength and the slip of FRP bar to concrete were studied systematically. Studies show that the failure mode is not the damage of the ribs or the shearing off of the ribs, but is shear failure between the screw thread and the core of the FRP bar, and the sands on the surface of the bar were grinded into powder. The descending branch of load-slip curve for the FRP bars is gentler than that for the steel bars. The bond strength of FRP bars is a little lower than that of steel bars, but higher than smooth FRP bar greatly. At last the FRP bar concrete specimen were modeled in ANSYS program and the simulation result is satisfactory, which proves the feasibility to model the behavior of bond-slip relationship between FRP bar and concrete accurately.

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