scholarly journals Experimental investigation on the flexural and post-cracking behaviour of geogrid-reinforced concrete overlays

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
N. S. Correia ◽  
G. M Dalfre
Keyword(s):  
Experimental Investigation ◽  
Reinforced Concrete ◽  
Portland Cement ◽  
Concrete Beam ◽  
Load Capacity ◽  
Mouth Opening ◽  
Energy Performance ◽  
Reinforced Concrete Beams ◽  
Bending Test ◽  
Concrete Overlays

Innovative materials are on the rise as alternatives to steel reinforcement in concrete structures. Recently, the use of polymeric geogrids as reinforcement elements has expanded into Portland cement concrete (PCC) overlays rehabilitation. Research conducted to date has indicated that the use of geogrids as reinforcement in concrete pavements shows both post cracking ductility and superior load capacity. Although this topic is not so explored in the literature, the use of geogrids in thin concrete overlays, pathway, pedestrian sidewalks and floating slabs is promising and gives a new employment area for the use of geogrid reinforcements. This paper presents an experimental investigation on the flexural behaviour, post-cracking and fracture energy performance of geogrid-reinforced concrete beams under four-point bending test. Different geogrids were embedded at one-third depth (from bottom) of concrete beam specimens (500 × 150 × 150 mm). The PCC mix was prepared using Ordinary Portland Cement (OPC grade 53) with compressive strength of 40 MPa. Results confirmed that the flexural performance and post-cracking resistance of the concrete beam specimens could be enhanced by the presence of geogrids, as evidenced by load-deflection response, crack mouth opening displacements and change in failure mode. Triaxial geogrids showed 11% increase in flexural strength of concrete beam, highlighting the potential benefits of geogrids reinforcements in PCC overlays.

RETROFITTING PERFORMANCE OF REINFORCED CONCRETE ONE WAY SLAB

2016 ◽  
Vol 78 (5-3) ◽  
Author(s):  
Norliyati Mohd Amin ◽  
Nur Aqilah Aziz ◽  
Ilya Joohari ◽  
Anizahyati Alisibramulisi
Keyword(s):  
Reinforced Concrete ◽  
Concrete Slab ◽  
Load Capacity ◽  
Reinforced Concrete Beams ◽  
Fiber Reinforced Polymer ◽  
Bending Test ◽  
Strength Performance ◽  
Concrete Crack ◽  
Reinforced Polymer ◽  
Structural Capacity

Cracks in concrete structure have always been a big threat on the strength of the concrete. Crack is one of the common deterioration observed in reinforced concrete beams and slabs. Concrete cracking is a random process, highly variable and influenced by many factors. To restore the structural capacity of the concrete damages, retrofitting and strengthening are required. There are several techniques that are used for retrofitting and strengthening reported in the literature [1], [2], [3]. This paper investigates the strength performance of retrofitting and strengthening methods of reinforced concrete one-way slab. Flexural bending test are performed on three different concrete slab of size 1000 mm x 500 mm x 75 mm. The methods that are used for retrofit are epoxy injection and patching and for the strengthening is lamination of carbon fiber reinforced polymer. The slabs were loaded to a certain stage where the cracks were formed for retrofitting and strengthening procedure. The achieved failure mode and load capacity of the concrete slab were observed. The repaired techniques for restoring and improving the structural capacity of cracked concrete slabs were analyzed. The ultimate load achieved for the epoxy injection laminate was 19.60 kN followed by CFRP laminate and patching that were 17.64 kN and 17.03 kN respectively. While the deflection value for the three specimens were 14.42 mm, 4.49 mm and 7.036 mm.  

scholarly journals The flexural behavior model of bamboo reinforced concrete beams using a hose clamp

2019 ◽  
Vol 276 ◽  
pp. 01033
Author(s):  
Muhtar ◽  
Sri Murni Dewi ◽  
Wisnumurti ◽  
As’ad Munawir
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beam ◽  
Load Capacity ◽  
Reinforced Concrete Beam ◽  
Load Test ◽  
Reinforced Concrete Beams ◽  
Flexural Behavior ◽  
Steel Reinforced Concrete ◽  
And Behavior ◽  
Hose Clamp

Bamboo can use at the simple concrete construction because of the tensile strength of its mechanical property. Meanwhile, a slippery surface of the bamboo caused cracks in the bamboo reinforced concrete beam (BRC) not to spread and yield slip failure between a bamboo bar and concrete. Load test at the BRC beam yield humble load capacity. This study aims to improve the capacity and behavior of BRC beam bending by giving waterproof coating, sand, and hose clamp installation. The beam test specimen with the size of 75x150x1100mm made as many as 26 pieces with the variety of reinforcement. The hose clamp used on the bamboo reinforcement varies with a distance of 0 cm, 15 cm, 20 cm, and 25 cm. The testing using a simple beam with two-point loading. The test results show that BRC beams have different bending behavior compared to the steel reinforced concrete beam (SRC).

scholarly journals Debonding Detection and Monitoring for CFRP Reinforced Concrete Beams Using Pizeoceramic Sensors

Materials ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2150 ◽  
Author(s):  
Shukui Liu ◽  
Wei Sun ◽  
Hongwen Jing ◽  
Zhaoxing Dong
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beam ◽  
Concrete Beams ◽  
Low Cost ◽  
Ultrasonic Waves ◽  
Reinforced Concrete Beams ◽  
Bending Test ◽  
Cfrp Sheet ◽  
Debonding Detection

The bonding status between Carbon Fiber Reinforced Polymer (CFRP) and concrete is one of the key issues for the safety of CFPR-reinforced structures, thus it is of great importance to detect the debonding as early as possible. Instead of detecting the debonding which is artificially set at the very beginning, this paper investigates the feasibility of using low-cost piezoceramic sensors to detect and monitor the debonding of CFRP-reinforced concrete beams in situ. For existing debonding detection, a concrete beam reinforced with CFRP sheet was loaded through the three-point bending test till failure to induce debonding between CFRP sheet and the concrete substrate, and piezoceramic sensors were used to detect the existing debonding by analyzing the receiving ultrasonic waves. In addition, the debonding detection results were further compared with and verified by the vision-based strain testing results. For in-situ debonding monitoring, 10 piezoceramic sensors were used as an array to track the wave transmission changes during the loading process of a CFRP-reinforced concrete beam, and the debonding development process was successfully monitored. The test results show that the low-cost piezoceramic sensors are very effective to generate and receive ultrasonic waves, and are capable of detecting the existing debonding and monitoring of the in-situ debonding process as well.

scholarly journals Flexural performance of reinforced concrete beams made with locally sourced fly ash

2021 ◽  
Vol 15 (2) ◽  
pp. 38-50
Author(s):  
Nguyen Van Chinh
Keyword(s):  
Reinforced Concrete ◽  
Fly Ash ◽  
Portland Cement ◽  
Concrete Beam ◽  
Concrete Beams ◽  
Reinforced Concrete Beam ◽  
Reinforced Concrete Beams ◽  
Flexural Performance ◽  
Steel Bars ◽  
Cracking Pattern

The paper investigates the flexural performance of reinforced concrete beams in which fly ash from Vinh Tan power station was used to replace original Portland cement in the proportions of 0%, 10%, 20% and 40% by weight. Twelve reinforced concrete beams with the dimensions of 100×150 mm in cross section and 1000 mm in length were cast and cured in water. These beams were flexurally tested under 4 points bending at 28 days, 56 days and 90 days. Load deflection curves, first cracking load, yielding of steel bars, ultimate load, and cracking pattern of the reinforced concrete beams are used to investigate the performance of the control and fly ash beams at 28 days, 56 days and 90 days. The results show that locally sourced fly ash does not affect the load and deflection curves. Fly ash reduced slightly the flexural strength of reinforced concrete beams at 90 days when 40% of fly ash was used to replaced Portland cement. Keywords: fly ash; reinforced concrete beam; flexural performance; load; deflection.

scholarly journals Numerical Investigation of the Behavior of Reinforced Concrete Beam Reinforced with FRP Bars

2019 ◽  
Vol 5 (11) ◽  
pp. 2296-2308 ◽  
Author(s):  
Rania Salih Mohammed ◽  
Zhou Fangyuan
Keyword(s):  
Finite Element ◽  
Reinforced Concrete ◽  
Concrete Beam ◽  
Load Capacity ◽  
Reinforced Concrete Beam ◽  
Prediction Equation ◽  
Reinforced Concrete Beams ◽  
Finite Element Software ◽  
Concrete Damage ◽  
Frp Bars

In this study, the behavior of reinforced concrete beams reinforced with FRP bars was investigated. A total of seventeen models were carried out based on the finite element software (ABAQUS). The concrete damage plasticity modeling was considered. Two types of fiber polymer bars, CFRP and GFRP as longitudinal reinforcement for concrete beam were used. The validation of numerical results was confirmed by experimental results, then the parametric study was conducted to evaluate the effect of change in different parameters, such as (diameter size, number of bars), type of FRP bars, longitudinal arrangement for FRP bars. All results were analyzed and discussed through, load-deflection diagram, according, to the difference parameter considered. The results showed that the use of FRP bars in rebar concrete beam improves the beam stiffness and enhance the cracking load. The load capacity enhanced in the range of (7.88-64.82%) when used CFRP bars. The load-carrying capacity of beams strengthened with CFRP is higher than that of strengthened with GFRP. Furthermore, the use of FRP bars in bottom and steel in top reinforcement is useful to overcome the large deflection, and improving the beam ductility. Finally, the results of finite element models were compared with the prediction equation, according to ACI440.1R-15.

A prototype knowledge-based expert system for the design and detailing of reinforced concrete beams

1991 ◽  
Vol 18 (6) ◽  
pp. 1005-1012
Author(s):  
George Akhras ◽  
John A. Fedoruk
Keyword(s):  
Reinforced Concrete ◽  
Expert System ◽  
Concrete Beam ◽  
Concrete Beams ◽  
Load Capacity ◽  
Reinforced Concrete Beam ◽  
Reinforced Concrete Beams ◽  
Graphical Form ◽  
Knowledge Based ◽  
Beam Design

Most computer programs developed for reinforced concrete beam design either analyze a given cross section for load capacity or offer a limited solution from which the engineer must continue toward the final design. These programs are very useful in performing many tedious calculations. However, they generally do not offer assistance in areas of design that require intuitive reasoning, experiential knowledge, rules of thumb, and sound engineering judgement. This type of heuristic knowledge has been incorporated into a prototype knowledge-based expert system for reinforced concrete beam design and detailing called BeamEx. BeamEx interacts with the user to advise and establish suitable parameters required for the comprehensive design of rectangular simply supported and continuous beams. It incorporates heuristic rules drawn from the governing Canadian codes and textbooks to design alternative suitable beams which are presented in graphical form. It is shown that a knowledge-based system approach can be used effectively in engineering design by encapsulating domain expertise in a program to complement and check the experience of the users in design. Key words: knowledge-based expert system, reinforced concrete, beams, design, detailing.

scholarly journals Openings Effect on the Performance of Reinforced Concrete Beams Loaded in Bending and Shear

2020 ◽  
Vol 10 (2) ◽  
pp. 5352-5360
Author(s):  
F. El Ame ◽  
J. N. Mwero ◽  
C. K. Kabubo
Keyword(s):  
Reinforced Concrete ◽  
Failure Mode ◽  
Concrete Beams ◽  
Load Capacity ◽  
Maximum Load ◽  
Reinforced Concrete Beams ◽  
Engineering Properties ◽  
Bending Test ◽  
Shear Cracks ◽  
Codes Of Practice

Transverse openings are often provided to reinforced concrete beams to accommodate utility ducts and pipes. This technique is usually adopted to avoid the creation of dead space in structures caused by extended dropped ceilings and leads to significant cost saving. On the other hand, the provision of openings through a beam creates a reduction in its strength and affects serviceability. In this study, ten reinforced concrete beams were cast using C30 concrete. Material characterization and engineering properties tests were carried out to ensure compliance with the requirements provided by the codes of practice. The effect of vertical positioning and size of openings was investigated through subjecting the beams to a four-point bending test after 28 days of curing. Maximum load capacity, first cracking load, and deflections at mid-span were recorded and crack pattern and failure mode were evaluated. Test data showed that openings of depth greater than 0.4d significantly affect the beams’ strength and lead to earlier cracking, while the failure mode remains essentially the same, a diagonal tension crack through the opening except for opening of 0.5d size where the failure occurred by a sudden formation of two independent shear cracks above and below the opening. When holes were located above the centroid of the section, the beams exhibited a lesser deflection characterized by the absence of plastic deformation. Furthermore, a significant reduction in strength was recorded compared to cases where the positioning of openings was in tension chords. This was validated using equations from the ACI code of reinforced concrete design.

The Shear and Durability of CFRP Reinforced Concrete Beams

2011 ◽  
Vol 368-373 ◽  
pp. 1500-1504
Author(s):  
Ruo Dong Ge ◽  
Zheng Zhuo Yin ◽  
Ji Hong Zhang
Keyword(s):  
Experimental Investigation ◽  
Reinforced Concrete ◽  
Comparative Analysis ◽  
Carbon Fiber ◽  
Concrete Beam ◽  
Shear Failure ◽  
Concrete Beams ◽  
Chloride Ion ◽  
Shear Capacity ◽  
Reinforced Concrete Beams

At present, the research on the performance of the shear and durability of CFRP reinforced concrete beams is few, the destruction of the curved and scissor section is often much subtle and suddenly. Based on the experimental investigation on the durableness of the CFRP concrete beams which has been shear reinforced and non-reinforced in the chloride ion erode, a comparative analysis on the fissure development, deflection, electrochemistry index and strain of the concrete beam were given under load. The results indicate that carbon fiber could limit the fissure development efficiently, and there were not the shear failure after loading, the beams with carbon could improve its shear capacity and durability efficiently, But The increase of durability is more depends on the reinforcement way.

scholarly journals Stiffness and Strength Analysis of Flexural RC beams strengthened with CFRP Sheets Considering the Influence of Pre-cracking

Mechanika ◽  
2020 ◽  
Vol 26 (4) ◽  
pp. 277-284
Author(s):  
Tadas LISAUSKAS ◽  
Mindaugas AUGONIS ◽  
Tadas ZINGAILA ◽  
Mario Rui Tiago ARRUDA
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beam ◽  
Reinforced Concrete Beam ◽  
Reinforced Concrete Beams ◽  
Bending Test ◽  
Experimental Program ◽  
Strength Analysis ◽  
Rc Beams ◽  
Cfrp Sheets ◽  
Good Agreement

                           This paper presents experimental, numerical and analytical analysis of newly cast and pre-cracking flexural reinforced concrete beams strengthened with CFRP. In total, 9 intermediate-scale composite beams were cast and tested using 4-point bending test setup. Midspan deflection, width of the cracks, concrete and CFRP strains were measured during the experimental program. Clear efficiency of composite pre-cracked beams was observed in comparison to newly cast beams: enhanced flexural capacity and increased stiffness after appearance of primary cracks in tension zone. Good agreement was found comparing experimental and theoretical (EC2) deflections of RC beams strengthened with CFRP. However, for more detailed verification, the analysis should be extended with more specimens. The shear stress at the end of CFRP sheets between the concrete and CFRP increased rapidly until reaching maximum slip value, when the reinforced concrete beam strengthened with CFRP reaches 60-90 % utilization of load bearing capacity. All experimental results were compared with numerical and analytical calculations. Experimental, numerical and analytical results were in sufficiently good agreement.

scholarly journals THE STUDY OF BENDING BEAMS MECHANICALS PROPERTIES WITH MICRO REINFORCEMENT

2021 ◽  
Vol 10 (2) ◽  
pp. 80-86
Author(s):  
Andi Yusra ◽  
Lissa Opirina ◽  
Teuku Farizal
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beam ◽  
Concrete Beams ◽  
Natural Fibers ◽  
Reinforced Concrete Beam ◽  
Bamboo Fiber ◽  
Reinforced Concrete Beams ◽  
Bending Test ◽  
Fiber Concrete ◽  
Bamboo Fibers

research on fiber concrete is currently growing very rapidly. The alternative fibers used in the concrete mix-ture is to use natural fibers. In this study, researchers used bamboo fiber as a substitute for artificial fiber, where Bamboo has a good tensile strength. The aim of this study to increase beam strength in sustaining ex-ternal loads by added bamboo fibers. The content of fiber additional to the concrete mixture was 1.5% of the cement weight. The mix design of concrete using ratio of cement water 0.25. The plasticizer and filler added in the mixture with the content of 2% and 15% cement weight, respectively. Two reinforced concrete beam specimens and 24 concrete cylinder specimens used in the study. Tests carried out of 28 days, and 56 days for cylindrical concrete, while bending test conducted of CBR1 and CBR2 at 28 test life only. In study show that addition 1.5% bamboo fiber to reinforced concrete beams increased the flexural capacity and ductility of the beams

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