Degradation of basalt FRP bars in alkaline environment

AbstractThis paper investigates the degradation of basalt fiber reinforced polymer (BFRP) bars used for concrete construction in an alkaline environment. The relationships between tensile strength, elastic modulus, shear strength and moisture absorption rate over time are analyzed using a tension test, short-beam test and moisture absorption weighting. The tensile strength degradation of BFRP bars was further compared with that of Glass FRP (GFRP) bars in the literature. The results indicated that BFRP bars exhibit relatively good resistance to alkaline corrosion, maintaining more than 60% of their original strength after 9 weeks at 55°C in an alkaline solution. The moisture absorption of BFRP bars conforms to Fick’s law, which shows that the degradation mechanism is controlled by matrix and related interface degradation. This finding is supported by comparison with the shear strength degradation trend. Compared to GFRP bars under similar alkaline conditions, BFRP bars exhibit a similar degradation rate during the initial phase, but maintain higher tensile strength and strength retention over time.

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Degradation of Glass Fiber Reinforced Polymer (GFRP) Material Exposed to Tropical Atmospheric Condition

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.879.265 ◽

2021 ◽

Vol 879 ◽

pp. 265-274

Author(s):

Mousay Mohammed ◽

Yew Ying Chai ◽

Shu Ing Doh ◽

Kar Sing Lim

Keyword(s):

Tensile Strength ◽

Tensile Test ◽

Oil And Gas ◽

Degradation Mechanism ◽

Atmospheric Condition ◽

Reinforced Polymers ◽

Longitudinal Splitting ◽

Glass Fiber Reinforced ◽

Before And After ◽

Original Strength

Fibre reinforced polymers (FRPs) have emerged as popular materials for structural application in recent decades due to numerous of advantages. Despite the growing body of research on the use of glass fibre reinforced polymers (GFRP) composites in repairing and retrofitting the important structures such as oil and gas pipelines, the lack of comprehensive data on the long-term degradation mechanism for these materials is still impeding their widespread use in open-air structures repairs particularly in tropical climate locations such as Malaysia. Therefore, this paper presents an experimental investigation to determine the influence of tropical atmospheric condition on tensile properties of the GFRP. In this study, a set of GFRP samples were fabricated using epoxy resin as polymer matrix and woven E-glass fibres as reinforcing materials. These samples were exposed to tropical atmospheric condition in Malaysia for a period of four months. Tensile test was carried out for each sample before and after four-months period of exposure. The experimental tensile test results recorded a 15% reduction in tensile strength after 4 months of exposure as compared to its original strength. Further, the dominant failure mode of the exposed sample was characterized with longitudinal splitting of the fibres without completely breaking out. Overall, the tropical atmospheric condition has a noticeable impact on the GFRPs tensile strength degradations over the exposure duration.

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Tensile Strength and Degradation of GFRP Bars under Combined Effects of Mechanical Load and Alkaline Solution

Materials ◽

10.3390/ma13163533 ◽

2020 ◽

Vol 13 (16) ◽

pp. 3533 ◽

Cited By ~ 1

Author(s):

Qingping Jin ◽

Peixia Chen ◽

Yonghong Gao ◽

Aihua Du ◽

Dongxu Liu ◽

...

Keyword(s):

Tensile Strength ◽

Alkaline Solution ◽

Mechanical Load ◽

Three Dimensional ◽

Strength Degradation ◽

Combined Effects ◽

Gfrp Bars ◽

Reinforced Polymer ◽

Glass Fiber Reinforced ◽

Stress Levels

Mechanical properties of glass fiber reinforced polymer (GFRP) composites degrade under the combined effects of mechanical load and alkaline solution, affecting the service ability and safety of GFRP reinforced structures. In this study, GFRP bars were loaded with cyclic tension at different stress levels and immersed in alkaline solution for days to investigate the tensile properties and degradation law of GFRP bars. The degradation mechanisms were studied at micro-, meso- and macro-scales with scanning electron microscopy (SEM) and three-dimensional X-ray microscopy, respectively. The results show that tensile strength and degradation rate of GFRP bars are mainly dependent on the different stress levels and alkaline solution. When stress level is higher, the tensile strength degrades more quickly, especially in the early stages of soaking. With the loading and immersion time, the elastic modulus and Poisson’s ratio increase at first and then decrease. The ultimate tensile strain is relatively stable, whereas the ultimate elongation is significantly reduced. A strength-degradation model was proposed and fit well with experimental data, demonstrating that the model can be applied to predict tensile strength degradation under combined effects of the load and alkaline solution.

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Comparison of water uptake behavior on tensile property of epoxy impregnated continuous basalt and slag filament composites

International Journal of Modern Physics B ◽

10.1142/s021797922040130x ◽

2020 ◽

Vol 34 (22n24) ◽

pp. 2040130

Author(s):

Se-Yoon Kim ◽

Soo-Jeong Park ◽

Chang-Wook Park ◽

Yun-Hae Kim

Keyword(s):

Tensile Strength ◽

Chemical Composition ◽

Moisture Absorption ◽

Basalt Fiber ◽

Value Added ◽

Tensile Loading ◽

Interfacial Bonding Strength ◽

The Difference ◽

Lower Tensile Strength

Slag fiber has economic and environmental advantages in that it converts a low-value-added material to a high-value-added material. However, although the slag fiber has a chemical composition similar to basalt fiber, its competitiveness in the fiber industry is significantly lower. Moreover, the slag fiber remains in the pre-commercial stage due to the uncertainty and instability of the basic properties. Therefore, in this study, the slag fiber customized through the fiberization process was compared with the existing basalt fiber to analyze the effect of the similarity of chemical composition on the environmental degradation characteristics and mechanical properties under tensile loading. As a result, the slag filament composites showed lower tensile strength due to the weaker interfacial bonding strength with the epoxy matrix than the basalt filament composites, but the difference in decreased tensile strength rate was not significant. In addition, long-term moisture absorption in fresh water and seawater demonstrated excellent moisture absorption resistance.

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Mechanical Properties of Chopped Basalt Fiber-Reinforced Lightweight Aggregate Concrete and Chopped Polyacrylonitrile Fiber Reinforced Lightweight Aggregate Concrete

Materials ◽

10.3390/ma13071715 ◽

2020 ◽

Vol 13 (7) ◽

pp. 1715 ◽

Cited By ~ 1

Author(s):

Yusheng Zeng ◽

Xianyu Zhou ◽

Aiping Tang ◽

Peng Sun

Keyword(s):

Tensile Strength ◽

Compressive Strength ◽

Shear Strength ◽

Water Absorption ◽

Basalt Fiber ◽

Lightweight Aggregate ◽

Splitting Tensile Strength ◽

Lightweight Aggregate Concrete ◽

Polyacrylonitrile Fiber ◽

Aggregate Concrete

In this study, an experimental investigation was conducted on the mechanical properties of lightweight aggregate concrete (LWAC) with different chopped fibers, including basalt fiber (BF) and polyacrylonitrile fiber (PANF). The LWAC performance was studied in regard to compressive strength, splitting tensile strength and shear strength at age of 28 days. In addition, the oven-dried density and water absorption were measured as well to confirm whether the specimens match the requirement of standard. In total, seven different mixture groups were designed and approximately 104 LWAC samples were tested. The test results showed that the oven-dried densities of the LWAC mixtures were in range of 1.819–1.844 t/m3 which satisfied the definition of LWAC by Chinese Standard. Additionally, water absorption decreased with the increasing of fiber content. The development tendency of the specific strength of LWAC was the same as that of the cube compressive strength. The addition of fibers had a significant effect on reducing water absorption. Adding BF and PANF into concrete had a relatively slight impact on the compressive strength but had an obvious effect on splitting tensile strength, flexural strength and shear strength enhancement, respectively. In that regard, a 1.5% fiber volume fraction of BF and PANF showed the maximum increase in strength. The use of BF and PANF could change the failure morphologies of splitting tensile and flexural destruction but almost had slight impact on the shear failure morphology. The strength enhancement parameter β was proposed to quantify the improvement effect of fibers on cube compressive strength, splitting tensile strength, flexural strength and shear strength, respectively. And the calculation results showed good agreement with test value.

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Numerical Evaluation of Shear Strength Degradation Mechanism Dependent on the Size Increase of RC Deep Beams with Height up to 1.5 Meter by Using 3D Rigid-Body-Spring-Method

Journal of Advanced Concrete Technology ◽

10.3151/jact.19.1245 ◽

2021 ◽

Vol 19 (12) ◽

pp. 1245-1263

Author(s):

Li Fu ◽

Hikaru Nakamura ◽

Shunyuan Chi ◽

Yoshihito Yamamoto ◽

Taito Miura

Keyword(s):

Shear Strength ◽

Rigid Body ◽

Numerical Evaluation ◽

Degradation Mechanism ◽

Strength Degradation ◽

Size Increase ◽

Deep Beams ◽

Rc Deep Beams ◽

Spring Method ◽

Shear Strength Degradation

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CENTRI-CAST GRAY IRON 50

Alloy Digest ◽

10.31399/asm.ad.ci0051 ◽

1981 ◽

Vol 30 (8) ◽

Keyword(s):

Tensile Strength ◽

Shear Strength ◽

Physical Properties ◽

Machine Tools ◽

Heat Treating ◽

Gray Iron ◽

Centrifugally Cast ◽

Wide Range ◽

Nominal Tensile Strength ◽

Cast Gray Iron

Abstract CENTRI-CAST GRAY IRON 50 is a centrifugally cast gray iron with a nominal tensile strength of 50,000 psi. It is cast in the form of tubing which has a wide range of uses in applications where size and shape are of paramount importance and freedom from pattern cost is an important consideration. Among its many applications are farm machinery, seals, bushings, machine tools and general machinery uses. This datasheet provides information on composition, physical properties, microstructure, hardness, elasticity, tensile properties, and compressive and shear strength as well as fatigue. It also includes information on casting, heat treating, machining, and surface treatment. Filing Code: CI-51. Producer or source: Federal Bronze Products Inc..

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CENTRI-CAST GRAY IRON 55

Alloy Digest ◽

10.31399/asm.ad.ci0048 ◽

1979 ◽

Vol 28 (9) ◽

Keyword(s):

Tensile Strength ◽

Shear Strength ◽

Physical Properties ◽

Surface Treatment ◽

Heat Treating ◽

Gray Iron ◽

Centrifugally Cast ◽

Wide Range ◽

Nominal Tensile Strength ◽

Cast Gray Iron

Abstract CENTRI-CAST GRAY IRON 55 is a centrifugally cast gray iron with a nominal tensile strength of 55,000 psi. It is produced in the form of tubing which has a wide range of uses in applications where size and shape are of paramount importance and freedom from pattern cost is an important consideration. Typical applications are seals, bushings, farm machinery, casings and general machinery uses. This datasheet provides information on composition, physical properties, microstructure, hardness, elasticity, tensile properties, and compressive and shear strength as well as fatigue. It also includes information on casting, heat treating, machining, and surface treatment. Filing Code: CI-48. Producer or source: Federal Bronze Products Inc..

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