FLEXURAL PERFORMANCE OF RC BEAMS UNDER TROPICAL CLIMATE EFFECTS

2014 ◽  
Vol 1 (1) ◽  
Author(s):  
Nauwal Suki ◽  
Mohd Hisbany Mohd Hashim ◽  
Afidah Abu Bakar
Keyword(s):  
Flexural Strength ◽  
Room Temperature ◽  
Tropical Climate ◽  
The Other ◽  
Bending Test ◽  
Rc Beams ◽  
Near Surface ◽  
Climate Effects ◽  
Flexural Performance ◽  
Temperature Conditions

This study investigates the flexural performance of RC beams under the effects of a tropical climate. Effects from the tropical climate, such as heat and rain throughout the year, may cause deterioration to the surface of concrete. Concrete will gradually erode and may expose the steel inside the beam. If the steel is exposed, it may be oxidized, thus decreasing the strength of the RC structure. To avoid this situation from happening, the Near Surface Mounted (NSM) method of strengthening may be applied as an alternative. Three beams with the size of 125 mm x 300 mm x 1800 mm (width; height; length) were constructed for this study. The first one is a beam without strengthening, while the other two beams were strengthened with CFRP plate horizontally positioned on the tension zones, where one beam is placed under room temperature conditions, while the other is left to endure the conditions of the tropical climate for a period of 6 months. All three beams were then tested under a four-point bending test. Results show that the strengthened beam placed under room temperature conditions has 1% more flexural strength compared to the exposed beam. The exposed beam, however, has 21% more flexural strength compared to the control beam. Thus, NSM is proven to strengthen beams even in a tropical climate.

FLEXURAL PERFORMANCE OF RC BEAMS WITH NEAR SURFACE MOUNTED CFRP PLATE

2014 ◽  
Vol 1 (1) ◽  
Author(s):  
Mohd Hisbany Mohd Hashim ◽  
Nauwal Suki ◽  
Afidah Abu Bakar
Keyword(s):  
Flexural Strength ◽  
Rc Beams ◽  
Tension Zone ◽  
Long Term Effects ◽  
Near Surface ◽  
Control Beam ◽  
Flexural Performance ◽  
Cfrp Plate ◽  
Near Surface Mounted

This study investigates the flexural performance of RC beams strengthened with Near Surface Mounted CFRP plate. In construction, deterioration tends to occur due to changes in loading capacity, improper design, or poor quality of workmanship. This will result in long-term effects as the strength decreases over time. To prepare for the long-term effects, the Near Surface Mounted (NSM) method can be used to strengthen the RC members. This is to ensure that a structure can continuously function for its intended purpose. Three beams of 125 mm x 300 mm x 1800 mm (width; height; length) were constructed for this study. The first beam was not strengthened, the second beam was strengthened with a CFRP plate horizontally positioned on the tension zone, and the third beam was strengthened with a CFRP plate vertically positioned on the tension zone. All three beams were then tested under a four point bending test. Results show that the beam with horizontal strengthening was able to increase the flexural strength of about 22% compared to the control beam, while the beam with vertical strengthening was able to increase the flexural capacity of about 43% compared to the control beam. This indicates that the NSM method can be used to significantly increase the flexural strength of RC members.

scholarly journals Effect of microwave disinfection on physical and mechanical properties of acrylic resins

2008 ◽  
Vol 19 (4) ◽  
pp. 348-353 ◽  
Author(s):  
Rafael Leonardo Xediek Consant ◽  
Erica Brenoe Vieira ◽  
Marcelo Ferraz Mesquita ◽  
Wilson Batista Mendes ◽  
João Neudenir Arioli-Filho
Keyword(s):  
Flexural Strength ◽  
Room Temperature ◽  
Physical And Mechanical Properties ◽  
Hardness Test ◽  
Knoop Hardness ◽  
Microwave Energy ◽  
Bending Test ◽  
Acrylic Resins ◽  
Strength Tests ◽  
The Impact

This study evaluated the effect of microwave energy on the hardness, impact strength and flexural strength of the Clássico, Onda-Cryl and QC-20 acrylic resins. Aluminum die were embedded in metallic or plastic flasks with type III dental stone, in accordance with the traditional packing technique. A mixing powder/liquid ratio was used according to the manufacturer's instructions. After polymerization in water batch at 74ºC for 9 h, boiling water for 20 min or microwave energy at 900 W for 10 min, the specimens were deflasked after flask cooling at room temperature, and submitted to finishing. Specimens non-disinfected and disinfected by microwave irradiation were submitted to hardness, impact and flexural strength tests. Each specimen was immersed in distilled water and disinfected in a microwave oven calibrated to 650 W for 3 min. Knoop hardness test was performed with 25 g load for 10 s, impact test was carried out using the Charpy system with 40 kpcm, and 3-point bending test with a crosshead speed of 0.5 mm/min until fracture. Data were submitted to statistical analysis by ANOVA and Tukey's test (?=0.05). Disinfection by microwave energy decreased the hardness of Clássico and Onda-Cryl acrylic resins, but no effect was observed on the impact and flexural strength of all tested resins.

Study on Flexural Performance of Damage RC Beams Strengthened with near Surface Mounted FRP Strips

2011 ◽  
Vol 94-96 ◽  
pp. 883-886 ◽  
Author(s):  
Chang Zhou Dong ◽  
Jian Zhong Xia
Keyword(s):  
Reinforced Concrete ◽  
Reinforced Concrete Beams ◽  
Rc Beams ◽  
Near Surface ◽  
Flexural Performance ◽  
Damage Degree ◽  
Reinforced Polymer ◽  
Significant Strength ◽  
Near Surface Mounted ◽  
Frp Strips

The contrast tests of 1 reinforced concrete(RC) beams and 4 RC beams strengthened with near-surface mounted carbon fiber reinforced polymer (FRP) strips have been carried out, under conditions of different damage degree of RC beams. It is mainly conducted to investigate the effects of FRP strips reinforcement of flexural strength. The experimental results indicate that significant strength on the ultimate load and rigidity of reinforced concrete beams can be realized by mounting FRP strips to the beams, and propagation of cracks were reduced obviously.

scholarly journals Experimental study on ventilation using earth-to-air heat exchanger in Surabaya

2021 ◽  
Vol 907 (1) ◽  
pp. 012015
Author(s):  
A Juniwati ◽  
D S Mintorogo ◽  
A E Abednego ◽  
S Kurnia ◽  
E A Handoyo
Keyword(s):  
Experimental Study ◽  
Heat Exchanger ◽  
Air Temperature ◽  
Thermal Condition ◽  
Room Temperature ◽  
Tropical Climate ◽  
The Other ◽  
Outdoor Air ◽  
The Earth ◽  
Typical Condition

Abstract The main problem related to thermal condition in Surabaya as a second-largest city in Indonesia is humid and hot. It is a typical condition of tropical climate. Ventilation in the hot day will bring warm and humid outdoor air into a room. It will increase the temperature of air in the room. One of some efforts to reduce the outdoor air temperature is using an earth to air heat exchanger (EAHE) to transfer heat from the air to the earth or ground. This paper will discuss about research done to study the effect of EAHE to a room temperature. The study used two model rooms which are similar and a model EAHE. One room called condition room will receive air flowing from the EAHE pipe and the other room is called the referent room. From the research, it is found that the air in condition room with EAHE is cooler in the daytime compared to the referent room. The temperature of the condition room with EAHE is more stable.

scholarly journals Experimental assessment of the performance of reinforced concrete beams strengthened with carbon fiber reinforced polymer laminates

2020 ◽  
Vol 39 (1) ◽  
pp. 105-112
Author(s):  
N. Yusuf ◽  
J.M. Kaura ◽  
A. Ocholi ◽  
M. Abbas
Keyword(s):  
Reinforced Concrete ◽  
Failure Modes ◽  
Reinforced Concrete Beams ◽  
Bending Test ◽  
Rc Beams ◽  
Flexural Strengthening ◽  
Cfrp Laminates ◽  
Flexural Performance ◽  
Load Carrying ◽  
Ultimate Load Carrying Capacity

In this study, experimental research is carried out to assess the flexural performance of RC beams strengthened with different amount of CFRP laminates at the tension face. Twelve rectangular RC beams were fabricated and three are un-strengthened and used as reference beams and the remaining nine are strengthened with different amount of CFRP varying from single to triple layers and all are tested to failure under three points bending test. The increase of ultimate strength provided by the bonded CFRP laminates is assessed and failure modes is identified and compared to the un-strengthened RC beams. The results indicated that the flexural capacity of the beams was significantly improved as the amount of the laminates increases that ranged from 20% to 52% increased for single to triple layers laminates. It is concluded that the attachment of CFRP laminates has substantial influence on the performance of CFRP strengthened RC beams. Based on the observed results, recommendations are made that externally application of CFRP laminates can be used for a significant enhancement of the strength deficient RC beams in increasing the ultimate load carrying capacity. Keywords: CPRP laminate, Reinforced concrete, ductility, index, epoxy resin, flexural strengthening

scholarly journals Flexural Performance of a New Hybrid Basalt-Polypropylene Fiber-Reinforced Concrete Oriented to Concrete Pipelines

Fibers ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 43
Author(s):  
Zhiyun Deng ◽  
Xinrong Liu ◽  
Ninghui Liang ◽  
Albert de la Fuente ◽  
Haoyang Peng
Keyword(s):  
Reinforced Concrete ◽  
Flexural Strength ◽  
Crack Width ◽  
Polypropylene Fiber ◽  
Basalt Fiber ◽  
Fiber Reinforced Concrete ◽  
Bending Test ◽  
Fiber Reinforced ◽  
Flexural Performance ◽  
Polypropylene Fiber Reinforced Concrete

The bending performance of a basalt-polypropylene fiber-reinforced concrete (HBPFRC) was characterized by testing 24,400 × 100 × 100 mm3 prismatic specimens in a four-point bending test JSCE-SF4 configuration. The type and content of both fibers were varied in order to guarantee different target levels of post-cracking flexural performance. The results evidenced that mono-micro basalt fiber reinforced concrete (BFRC) allows the increase of the flexural strength (pre-cracking stage), while macro polypropylene fiber reinforced concrete (PPFRC) can effectively improve both bearing capacity and ductility of the composite for a wide crack width range. Compared with the plain concrete specimens, flexural toughness and equivalent flexural strength of macro PPFRC and the hybrid fiber-reinforced concrete (HFRC) increased by 3.7–7.1 times and 10–42.5%, respectively. From both technical and economic points of view, the optimal mass ratio of basalt fiber (BF) to polypropylene fiber (PPF) resulted in being 1:2, with a total content of 6 kg/m3. This HFRC is seen as a suitable material to be used in sewerage pipes where cracking control (crack formation and crack width control) is of paramount importance to guarantee the durability and functionality of the pipeline as well as the ductility of the system in case of local failures.

Influence of Different Thickness of Zirconia Core on the Flexural Strength of Bilayered Ceramics in Artificial Saliva

2014 ◽  
Vol 602-603 ◽  
pp. 606-609
Author(s):  
Yan Li Zhang ◽  
Ruo Yu Liu ◽  
Xiao Li Feng ◽  
Liang Jiao Chen ◽  
Yao Kun Zhang ◽  
...  
Keyword(s):  
Flexural Strength ◽  
Test Data ◽  
Artificial Saliva ◽  
Multiple Comparisons ◽  
The Other ◽  
Bending Test ◽  
Core Thickness ◽  
Different Thickness ◽  
One Way Anova ◽  
Made In

To study the effect of different core thickness on the flexural strength of zirconia and feldspathic ceramics. Bilayered zirconia-feldspathic samples of three commercial brands were made in three different thickness(n=10): 0.5 mm, 0.8 mm and 1.0 mm respectively. On zirconia core specimens of each thickness, feldspathic dentin porcelain was added to reach a total crown thickness of 2 mm. Samples were stored in artificial saliva with neutral pH for 10 days at 37°C. Flexural strength was conducted with 3-point bending test. Data were analyzed by one-way ANOVA, and multiple comparisons were performed using Student-Newman-Keuls test(α=0.05). The measurement of 1.0 mm group was higher than the other groups, and 0.5 mm group was the lowest(P＜0.05), regardless of any commercial brand. Commercial dental zirconia blocks had varied flexural strength, Zirkonzahn expressed highest value in any thickness group compared with the other materials. Moreover, the fracture mode of zirconia bilayered composites was different in this study, 0.5 mm and 0.8 mm groups exhibited higher number of fragments and appeared to delamination compared with 1.0 mm group. So we infer that the thickness of core can have an effect on the flexural strength of bilayered zirconia-feldspathic crown, as well as different kinds of materials.

Influence of different Thickness of Zirconia Core on the Flexural Strength in Article Saliva

2013 ◽  
Vol 833 ◽  
pp. 173-176
Author(s):  
Guo Xi Yu ◽  
Le Wang ◽  
Zhang Fan
Keyword(s):  
Flexural Strength ◽  
Test Data ◽  
Artificial Saliva ◽  
Multiple Comparisons ◽  
The Other ◽  
Bending Test ◽  
Core Thickness ◽  
Different Thickness ◽  
One Way Anova ◽  
Made In

To Study the Effect of Different Core Thickness on the Flexural Strength of Zirconia and Feldspathic Ceramics. Bilayered Zirconia-Feldspathic Samples of Three Commercial Brands were Made in Three Different Thickness(n=10): 0.5 Mm, 0.8 Mm and 1.0 Mm Respectively. on Zirconia Core Specimens of each Thickness, Feldspathic Dentin Porcelain was Added to Reach a Total Crown Thickness of 2 Mm. Samples were Stored in Artificial Saliva with Neutral Ph for 10 Days at 37°C. Flexural Strength was Conducted with 3-Point Bending Test. Data were Analyzed by One-way ANOVA, and Multiple Comparisons were Performed Using Student-Newman-Keuls Test(α=0.05). the Measurement of 1.0 Mm Group was Higher than the other Groups, and 0.5 Mm Group was the Lowest(P＜0.05), Regardless of any Commercial Brand. Commercial Dental Zirconia Blocks had Varied Flexural Strength, Zirkonzahn Expressed Highest Value in any Thickness Group Compared with the other Materials. Moreover, the Fracture Mode of Zirconia Bilayered Composites was Different in this Study, 0.5 Mm and 0.8 Mm Groups Exhibited Higher Number of Fragments and Appeared to Delamination Compared with 1.0 Mm Group. so we Infer that the Thickness of Core can have an Effect on the Flexural Strength of Bilayered Zirconia-Feldspathic Crown, as well as Different Kinds of Materials.

Mechanical and Fracture Properties of R-Glass Reinforced Composites with Pyrolysed Polysiloxane Resin as a Matrix

2005 ◽  
Vol 290 ◽  
pp. 344-347
Author(s):  
Miroslav Černý ◽  
D. Bednářová ◽  
Petr Glogar ◽  
Ján Dusza ◽  
Emőke Rudnayová
Keyword(s):  
Flexural Strength ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
The Other ◽  
Reinforced Composites ◽  
Fracture Properties ◽  
The Matrix ◽  
Mechanical And Fracture Properties ◽  
The Impact ◽  
Glass Reinforced Composites

Mechanical and fracture properties of unidirectional composites reinforced with R-glass fibres and utilizing various commercially available polysiloxane resins as matrix precursors were investigated. As the matrix becomes more brittle after the pyrolysis the impact toughness and flexural strength of the composites fall. On the other hand, the shear modulus rises after the pyrolysis as the matrix becomes stiffer in shear. The appearance of fracture surfaces generated during the flexural strength at room temperature (RT) and elevated temperatures is discussed.

Effect of Repeated Preheating Cycles on Flexural Strength of Resin Composites

2013 ◽  
Vol 38 (1) ◽  
pp. 33-38 ◽  
Author(s):  
M D'Amario ◽  
S Pacioni ◽  
M Capogreco ◽  
R Gatto ◽  
M Baldi
Keyword(s):  
Flexural Strength ◽  
Room Temperature ◽  
Testing Machine ◽  
Bending Test ◽  
Resin Composites ◽  
Control Groups ◽  
Three Point Bending ◽  
Universal Testing ◽  
Group A ◽  
Significant Factors

SUMMARY The aim of this study was to assess the flexural strengths of three resin composites prepared at room temperature or cured after 20 or 40 cycles of preheating to a temperature of 45°C. Three resin composites were evaluated: Enamel Plus HFO (Micerium) (HFO), Enamel Plus HRi (Micerium) (HRi), Opallis + (FGM) (OPA). One group of specimens for each composite was fabricated under ambient laboratory conditions, whereas in the other groups, the composites were cured after 20 or 40 preheating cycles to a temperature of 45°C in a preheating device. Ten specimens were prepared for each group. A three-point bending test was performed using a universal testing machine at a crosshead speed of 0.5 mm/min. Data were analyzed with a two-way analysis of variance (ANOVA) test and a Games-Howell test (α = 0.05). The two-way ANOVA showed that both the material and the number of heating cycles were significant factors, able to influence the flexural strength values (p<0.05). However, there was not a statistically significant interaction (p>0.05). For all three composites flexural strengths were not affected after 20 preheating cycles in comparison with the control groups (0 preheating cycles) but were, however, significantly decreased when 40 prewarming cycles were conducted. The HRi and OPA groups had the highest flexural strengths, with no statistically significant differences among them. HFO presented significantly lower flexural strengths in comparison with HRi.

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