Flexural strength and serviceability evaluation of concrete beams reinforced with deformed GFRP bars

2019 ◽  
Vol 186 ◽  
pp. 282-296 ◽  
Author(s):  
Omar I. Abdelkarim ◽  
Ehab A. Ahmed ◽  
Hamdy M. Mohamed ◽  
Brahim Benmokrane
2018 ◽  
Vol 173 ◽  
pp. 606-619 ◽  
Author(s):  
Amr El-Nemr ◽  
Ehab A. Ahmed ◽  
Adel El-Safty ◽  
Brahim Benmokrane

2021 ◽  
pp. 136943322110015
Author(s):  
Akram S. Mahmoud ◽  
Ziadoon M. Ali

When glass fibre-reinforced polymer (GFRP) bar splices are used in reinforced concrete sections, they affect the structural performance in two different ways: through the stress concentration in the section, and through the configuration of the GFRP–concrete bond. This study experimentally investigated a new method for increasing the bond strength of a GFRP lap (two GFRP bars connected together) using a carbon fibre-reinforced polymer (CFRP) sheet coated in epoxy resin. A new splicing method was investigated to quantify the effect of the bar surface bond on the development length, with reinforced concrete beams cast with laps in the concrete reinforcing bars at a known bending span length. Specimens were tested in four-point flexure tests to assess the strength capacity and failure mode. The results were summarised and compared within a standard lap made according to the ACI 318 specifications. The new method for splicing was more efficient for GFRP splice laps than the standard lap method. It could also be used for head-to-head reinforcement bar splices with the appropriate CFRP lapping sheets.


2013 ◽  
Vol 49 ◽  
pp. 949-961 ◽  
Author(s):  
Pedro Santos ◽  
Gilberto Laranja ◽  
Paulo M. França ◽  
João R. Correia

2019 ◽  
Vol 9 (3) ◽  
pp. 4213-4217 ◽  
Author(s):  
A. H. Buller ◽  
M. Oad ◽  
B. A. Memon ◽  
S. Sohu

In this article, the effect of prolonged fire (24-hour duration) on reinforced concrete beams made with recycled aggregates from demolished concrete was experimentally investigated. Demolished concrete was used recycled coarse aggregates in equal proportion with natural coarse aggregates. Normal and rich mix concrete with water-cement ratio equal to 0.54 were used. As a control specimen, beams with all-natural aggregates were also cast to compare with the results of the proposed beams. All beams were cured for 28 days and exposed to fire at 1000°C in an oven for 24 hours. After the elapse of this fire period, the beams were allowed to air cool, followed by testing till failure in a universal load testing machine. Comparison of the test results shows that rich mix concrete beams more reduction in flexural strength, more increase in maximum load carrying capacity and deflection than normal mix beams. The maximum reduction in flexural strength was 32.41% for beams cast with 50% RCA and rich mix. Although the fire duration used in this study is rare, yet the outcome provides guidelines for taking proper decisions for retrofitting/strengthening of the fire affected structure before putting it back in service.


Author(s):  
Indrayani Indrayani ◽  
Lina Flaviana Tilik ◽  
Djaka Suhirkam ◽  
Suhadi Suhadi ◽  
Muhammad Prawira Wardana ◽  
...  

Currently, innovation continues to be developed to replace cement with other materials so that the use of cement as a building material can be reduced. Utilization of coal waste (fly ash) is an alternative to subtitude cement. From previous studies, fly ash mixed with alkaline materials in the form of NaOH and Na2SiO3 in a ratio of 1:5 can produce geopolymer concrete. This geopolymer concrete research was continued by adding bendrat wire fibers into the geopolymer concrete mixture. The method used in testing the aggregate, testing the compressive strength of normal concrete K225, testing the flexural strength of normal concrete and geopolymer concrete refers to SNI. Another additional material that is mixed is bendrat wire fiber. The research was carried out in the form of making flexible beams of 10 cm x 10 cm x 50 cm with fiber variations of 0%, 0.5%, and 1,0% at the age of 14 and 28 days. The results of the flexural strength test of the BN beam at the age of 28 days can withstand loads than BG. The average flexural strength obtained with variations of BN, BN+SB 0.5% and BN+SB 1.0% respectively were 2.796 MPa, 3.113 MPa, and 3.879 MPa. The results of testing the average flexural strength of geopolymer concrete beams at 28 days, obtained variations of BG, BG+SB 0.5%, and BG+SB 1.0% respectively were 0 MPa, 0.055 MPa and 0.104 MPa. In addition, geopolymer concrete cannot be used as a beam and the addition of bendrat wire fiber to geopolymer concrete cannot withstand the tensile load on the concrete.


2018 ◽  
Vol 6 (6) ◽  
pp. 453-460
Author(s):  
Chijioke C ◽  
Nwaiwu ◽  
Aginam ◽  
Anyadiegwu

This work focuses on the 100% replacement of river sand with quarry dust in the production of concrete. Two types of concrete were produced (concrete made with river sand and that made with quarry dust as fine aggregate), the concretes produces were cast into beams and cured for 28 days. The flexural strengths of the concrete beams cast was determine at 28 day strength. At 28 days target strength the maximum flexural strength of concrete made with river sand as fine aggregate is 5.375111N/mm2 and minimum flexural strength is 2.2155N/mm2, for the concrete made with quarry dust as fine aggregate the maximum flexural strength is 2.567 N/mm2. The maximum value of 2.567 N/mm2 for concrete made with quarry dust as fine aggregate is higher than the minimum value of 2.2155N/mm2 for concrete made with river sand as fine aggregate. With this result it shows that quarry dust is a good substitute to river sand in the production of concrete.


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