scholarly journals Residual Mechanical Properties of Fiber-Reinforced Lightweight Aggregate Concrete after Exposure to Elevated Temperatures

2020 ◽  
Vol 10 (10) ◽  
pp. 3519 ◽  
Author(s):  
Chao-Wei Tang
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
High Temperature ◽  
Flexural Strength ◽  
Elevated Temperatures ◽  
Lightweight Aggregate ◽  
Lightweight Aggregate Concrete ◽  
Fiber Reinforced ◽  
Aggregate Concrete ◽  
Residual Mechanical Properties

In this study, the effects of individual and mixed fiber on the mechanical properties of lightweight aggregate concrete (LWC) after exposure to elevated temperatures were examined. Concrete specimens were divided into a control group (ordinary LWC) and an experimental group (fiber-reinforced LWC), and their compressive strength, elastic modulus, and flexural strength after heating to high temperatures of 400–800 °C were investigated. The four test parameters included concrete type, concrete strength, fiber type, and targeted temperature. The test results show that after exposure to 400–800 °C, the variation in mechanical properties of each group of LWC showed a trend of increasing first and then decreasing. After exposure to 400 °C, the residual mechanical properties of all specimens did not attenuate due to the drying effect of the high temperature and the more sufficient cement hydration reaction. However, after exposure to 800 °C, the residual mechanical properties significantly reduced. Overall, the mixed fiber-reinforced LWC showed a better ability to resist the loss of mechanical properties caused by high temperature. Compared with the loss of compressive strength, the flexural strength was relatively lost.

scholarly journals Experimental Research on High Temperature Resistance of Modified Lightweight Concrete after Exposure to Elevated Temperatures

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Ke-cheng He ◽  
Rong-xin Guo ◽  
Qian-min Ma ◽  
Feng Yan ◽  
Zhi-wei Lin ◽  
...  
Keyword(s):  
Compressive Strength ◽  
High Temperature ◽  
Elevated Temperatures ◽  
Lightweight Concrete ◽  
Lightweight Aggregate ◽  
Lightweight Aggregate Concrete ◽  
Modification Method ◽  
Superior Mechanical Properties ◽  
Axial Compressive Strength ◽  
Crushed Limestone

In order to improve the spalling resistance of lightweight aggregate concrete at high temperature, two types of modified materials were used to modify clay ceramsite lightweight aggregates by adopting the surface coating modification method. Spalling of the concrete specimens manufactured by using the modified aggregates was observed during a temperature elevation. Mass loss and residual axial compressive strength of the modified concrete specimens after exposure to elevated temperatures were also tested. Concrete specimens consisting of ordinary clay ceramsites and crushed limestone were manufactured as references for comparison. The results showed that the ordinary lightweight concrete specimens and the crushed limestone concrete specimens were completely spalled after exposure to target temperatures above 400°C and 1000°C, respectively, whereas the modified concrete specimens remained intact at 1200°C, at which approximately 25% to 38% of the residual compressive strength was retained. The results indicated that the modified lightweight concrete specimens have exhibited superior mechanical properties and resistance to thermal spalling after exposure to elevated temperatures.

Performance of ilmenite concrete at sustained elevated temperatures

1988 ◽  
Vol 15 (5) ◽  
pp. 776-783
Author(s):  
H. S. Wilson
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
High Temperature ◽  
Flexural Strength ◽  
Key Words ◽  
Elevated Temperatures ◽  
Cement Ratio ◽  
Nondestructive Tests ◽  
High Temperature Mechanical Properties ◽  
Curing Period

Two similar mixes were made with cement contents of about 350 kg/m3 and a water–cement ratio of 0.50. The concrete specimens, moist cured for 7 days, were cured in air for 28 and 120 days, respectively, prior to heating. The exposure temperatures were 75, 150, 300, and 450 °C. The periods of exposure at each temperature were 2, 30, and 120 days.The compressive strengths, before heating, of the specimens cured for 35 and 120 days were 41.0 and 46.2 MPa, respectively, and the flexural strengths were 4.9 and 5.8 MPa. Compared with those strengths, the strengths of the specimens heated for 30 days or more increased at 75 °C but decreased at higher temperatures. The losses increased with increase in temperature, reaching about 30% at 450 °C.The flexural strength of the concrete cured in air for 28 days was more adversely affected than was the compressive strength. The flexural and compressive strengths of the concrete cured in air for 120 days were affected to about the same degree. The longer curing period had little effect on the relative losses in compressive strength, but the longer curing period reduced the loss in flexural strength. In most applications, the loss in strength could be compensated by proportioning the mix to overdesign for strength. Key words: high-density concrete, ilmenite, aggregates, high temperature, mechanical properties, nondestructive tests.

Mechanical Properties of Modified Polypropylene Coarse Fiber-Reinforced, High-Strength, Lightweight Concrete

2011 ◽  
Vol 374-377 ◽  
pp. 1499-1506
Author(s):  
Rong Hui Zhang ◽  
Jian Li
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Compressive Strength ◽  
Flexural Strength ◽  
Lightweight Concrete ◽  
Volume Fraction ◽  
High Strength ◽  
Lightweight Aggregate Concrete ◽  
Fiber Reinforced ◽  
Fiber Volume

In this study, the effect of micro-expansion high strength grouting material (EGM) and Modified polypropylene coarse fiber (M-PP fiber) on the mechanical properties of lightweight concrete are investigated. The influence of EGM and M-PP fiber on compressive strength , flexural strength and drying shrinkage of concrete are researched, and flexural fracture toughness are calculated. Test results show that the effect of EGM and M-PP fiber volume fraction (Vf) on flexural strength and fracture toughness is extremely prominent, compressive strength is only slightly enhanced, and the rate of shrinkage is obviously decreased. It is observed that the shape of the descending branch of load-deflection and the ascending branch of shrinkage-age tends towards gently with the increase of Vf. And M-PP fiber reinforced lightweight aggregate concrete is more economical.

Experimental Study on Mechanical Properties of Hybrid Fiber Reinforced Full Lightweight Aggregate Concrete

2011 ◽  
Vol 197-198 ◽  
pp. 911-914 ◽  
Author(s):  
Li Yun Pan ◽  
Hao Yuan ◽  
Shun Bo Zhao
Keyword(s):  
Mechanical Properties ◽  
Apparent Density ◽  
Steel Fiber ◽  
Polypropylene Fiber ◽  
Lightweight Aggregate ◽  
Lightweight Aggregate Concrete ◽  
Fiber Reinforced ◽  
Mass Content ◽  
Hybrid Fiber ◽  
Aggregate Concrete

Tests were carried out to study mechanical properties of hybrid fiber reinforced full lightweight aggregate concrete (HFRFLAC), the hybrid fiber was composed by steel fiber and polypropylene fiber, the expanded-shale and lightweight sand were used as coarse and fine aggregates. The apparent density and strengths in cubic compressive, splitting tensile and flexural tensile states of HFRFLAC were obtained. The results show that the average dry apparent density increases with the increasing cement content, which is much more affected by fraction of steel fiber by volume than mass content of polypropylene fiber; the tensile strengths increase somewhat with the increasing mass content of polypropylene fiber; all of the strengths increase with the increasing fraction of steel fiber by volume, and obvious are the enhancement of tensile strengths; there are somewhat relevance between the effects of polypropylene fiber and steel fiber on mechanical properties of HFRFLAC.

scholarly journals The Research of Plastics-Steel Fibber Content on the Mechanical Properties of Light weight Aggregate Concrete

2020 ◽  
Vol 165 ◽  
pp. 04040
Author(s):  
Li Yunyun ◽  
Niu Jiangang ◽  
Yang Baosheng ◽  
Li Jingjun
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Steel Fibre ◽  
Impact Resistance ◽  
Lightweight Aggregate ◽  
Lightweight Aggregate Concrete ◽  
Light Weight ◽  
Aggregate Concrete ◽  
Light Weight Aggregate ◽  
Fibre Fraction

In this study, lightweight aggregate concrete (LWAC) specimens with different plastics-steel fibre volumes were tested to investigate the effect of plastics-steel fibre fraction on the mechanical properties of LWAC through the experimental research and theoretical analysis. The experimental results indicated that incorporation of steel fibre into LWAC can greatly improve such mechanical properties as flexural toughness and impact resistance, but leads to a little effect on compressive strength and flexural strength.

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