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

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.

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Ming Kun Yew ◽  
Hilmi Bin Mahmud ◽  
Bee Chin Ang ◽  
Ming Chian Yew

This paper presents the effects of low volume fraction(Vf)of polyvinyl alcohol (PVA) fibers on the mechanical properties of oil palm shell (OPS) high strength lightweight concrete mixtures. The slump, density, compressive strength, splitting tensile strength, flexural strength, and modulus of elasticity under various curing conditions have been measured and evaluated. The results indicate that an increase in PVA fibers decreases the workability of the concrete and decreases the density slightly. The 28-day compressive strength of oil palm shell fiber-reinforced concrete (OPSFRC) high strength lightweight concrete (HSLWC) subject to continuous moist curing was within the range of 43–49 MPa. The average modulus of elasticity (E) value is found to be 16.1 GPa for all mixes, which is higher than that reported in previous studies and is within the range of normal weight concrete. Hence, the findings of this study revealed that the PVA fibers can be used as an alternative material to enhance the properties of OPS HSLWC for building and construction applications.


2010 ◽  
Vol 168-170 ◽  
pp. 1704-1707 ◽  
Author(s):  
Ming Kun Yew ◽  
Othman Ismail

The mechanical properties of hybrid nylon-steel-fiber-reinforced concrete were investigated in comparison to that of the steel-fiber-reinforced concrete, at the same volume fraction (0.5%). The combining of fibers, often called hybridization is investigated in this paper for a very high strength concrete of an average compressive strength of 105 MPa. Test results showed that fibers when used in a hybrid nylon-steel fibers reinforced concrete form could result in superior composite performance compared to steel-fiber-reinforced concrete. The basic property of the hybridized material that was evaluated and analyzed extensively was the modulus of rupture (MOR) and splitting tensile while the compressive strength was only slightly decreased compared to single steel fiber reinforced concrete. There is a synergy effect in the hybrid fibers system.


2020 ◽  
Vol 10 (10) ◽  
pp. 3519 ◽  
Author(s):  
Chao-Wei Tang

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.


2019 ◽  
Vol 8 (2) ◽  
pp. 8-15
Author(s):  
H. R. Arun Kumar ◽  
B. Shivakumaraswamy

Self Compacting Concrete is a material used in the construction that has excellent deformability in the fresh state and high resistance of segregation, and can be replaced and compacted under its self-weight without applying vibration which leads to substantial advantages related to better homogeneity, enhancement of working environment and improvement in the productivity by increasing the speed of construction. Concrete can be formulated with high compressive strength but always has lower tensile strength. Tensile strength and other properties of concrete can be enhanced by adding fibers due to which the workability of concrete mix reduces and in order to achieve the desired Workability super-plasticizers is added. In the present work the use of fibrofor fiber in the production of self-compacting concrete (SCC) has been studied to identify how fresh and hardened properties of SCC are affected by the addition of fibers. The fibrofor fiber of 19mm standard length is incorporated into the SCC mixtures as 0.5kg/m3, 1.0kg/m3, 1.5kg/m3of concrete. Test on fresh SCC like slump Flow test, T50, V-Funnel test, J-Ring slump test and L-Box test were performed for an understanding of flow of SCC and tests on hardened properties like flexural strength, compressive strength and split tensile strength have been conducted to identify the hardened properties of SCC produced with fibrofor fiber. A comparative study between plain concrete, SCC without fiber and SCC with fiber has been done. Mix design for M40 grade concrete has been done according to EFNARC guidelines. The results reveal that the use of fibro for fiber decreases the workability but increases the mechanical properties of SCC. The optimum volume fraction of fibrofor fiber is determined as 1kg/m3 considering the optimized flexural strength and split tensile strength based properties of SCC. Due to increase in strength properties of fiber reinforced SCC that can be used for pavement construction and various other structures such as buildings, water retaining structures, reservoir structures and tunnel etc.


2018 ◽  
Vol 19 (2) ◽  
pp. 30-42
Author(s):  
Md. Nazmul Huda ◽  
Mohd Zamin Jumaat ◽  
A. B. M. Saiful Islam ◽  
Walid A. Al-Kutti

The performance of high strength structural lightweight concrete (LWC) using the palm wastes, oil palm shell (OPS) as well as palm oil clinker (POC) has been reported. Existing literatures used either OPS or POC individually for production of LWC. Each concept has their own advantages-disadvantages. In this study, both OPS and POC have been put together as coarse aggregate on the way to see the improvement of mechanical properties of waste based LWC. To achieve this purpose, regular coarse aggregate has been fully replaced by OPS and POC in the concrete. This structural grade lightweight concrete is named as palm shell and clinker concrete (PSCC). Attempts have been made with the series of OPS and POC mixture aimed at identifying for better performance. The quantity of OPS and POC mix has been varied as 30%, 40%, 50%, 60% and 70%. Mechanical properties of PSCC like density, workability, compressive strength at different ages, flexural strength, splitting tensile strength as well as modulus of elasticity have been evaluated. It is revealed that the proposed PSCC has extensive potential in terms of high compressive strength and good material behavior to perform as a better LWC. The study could offer structural lightweight concrete of compressive strength up to 46 MPa that is 31% higher than the control mix. The usage of 50% OPS to 50% POC coarse aggregate by vol. in the concrete mix is found to be the optimum mix. Furthermore, simple correlations have been developed which can easily predict compressive strength, splitting tensile strength, flexural strength, modulus of elasticity and ultrasonic pulse velocity of lightweight concrete.


Author(s):  
Saman Hedjazi ◽  
Daniel Castillo

This paper evaluates the effect of discrete fibers in concrete on the pulse velocity and mechanical properties of FRC. Two different type of synthetic fibers consisting of Polypropylene and Nylon were investigated. The effect of concrete mix proportions such as types of fiber, volume fraction of fiber, water-to-cement ratio (w/c), and curing conditions were examined. An experimental program was designed and conducted on 100 mm x 200 mm cylindrical specimens to evaluate the properties of FRC. The compressive strength obtained from the Compression Test Machine (CTM) was compared to those calculated from UPV. The difference between two types of synthetic fibers on concrete properties were investigated. Results show that the highest compressive strength of Polypropylene Fiber Reinforced Concrete (PFRC) was achieved at 0.5% fiber volume fraction, whereas for Nylon Fiber Reinforced Concrete (NFRC) the highest compressive strength was obtained at 1.0% fiber volume fraction. Additionally, results show that the available equations relating UPV to compressive strength of concrete need modifications when used for different fibers. Therefore, either new or modified empirical equations are needed for better estimation of mechanical properties of FRC.


2016 ◽  
Vol 709 ◽  
pp. 101-104 ◽  
Author(s):  
Seok Joon Jang ◽  
Gwon Young Jeong ◽  
Mi Hwa Lee ◽  
Keitetsu Rokugo ◽  
Hyun Do Yun

This paper presents results of experimental investigation to evaluation the effects of compressive strength on flexural behavior of steel fiber-reinforced concrete (SFRC). For this purpose, normal and high strength SFRCs with two different fiber volume fractions of 0.5 and 1.0% were prepared. Compressive strength, modulus of elasticity, flexural strength and toughness were measured with tests on SFRC cylinders and prisms. Test results indicated that steel fiber volume fraction significantly affects the flexural strength and toughness of SFRC. However, the high strength SFRC showed reduction in flexural toughness compared with the normal strength SFRC. It can be concluded that flexural behavior of SFRC depends on both compressive strength and fiber volume fraction.


2021 ◽  
pp. 002199832110047
Author(s):  
Mahmoud Mohamed ◽  
Siddhartha Brahma ◽  
Haibin Ning ◽  
Selvum Pillay

Fiber prestressing during matrix curing can significantly improve the mechanical properties of fiber-reinforced polymer composites. One primary reason behind this improvement is the generated compressive residual stress within the cured matrix, which impedes cracks initiation and propagation. However, the prestressing force might diminish progressively with time due to the creep of the compressed matrix and the relaxation of the tensioned fiber. As a result, the initial compressive residual stress and the acquired improvement in mechanical properties are prone to decline over time. Therefore, it is necessary to evaluate the mechanical properties of the prestressed composites as time proceeds. This study monitors the change in the tensile and flexural properties of unidirectional prestressed glass fiber reinforced epoxy composites over a period of 12 months after manufacturing. The composites were prepared using three different fiber volume fractions 25%, 30%, and 40%. The results of mechanical testing showed that the prestressed composites acquired an initial increase up to 29% in the tensile properties and up to 32% in the flexural properties compared to the non-prestressed counterparts. Throughout the 12 months of study, the initial increase in both tensile and flexural strength showed a progressive reduction. The loss ratio of the initial increase was observed to be inversely proportional to the fiber volume fraction. For the prestressed composites fabricated with 25%, 30%, and 40% fiber volume fraction, the initial increase in tensile and flexural strength dropped by 29%, 25%, and 17%, respectively and by 34%, 26%, and 21%, respectively at the end of the study. Approximately 50% of the total loss took place over the first month after the manufacture, while after the sixth month, the reduction in mechanical properties became insignificant. Tensile modulus started to show a very slight reduction after the fourth/sixth month, while the flexural modulus reduction was observed from the beginning. Although the prestressed composites displayed time-dependent losses, their long-term mechanical properties still outperformed the non-prestressed counterparts.


2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Eethar Thanon Dawood ◽  
Mahyuddin Ramli

This study was conducted to determine some physical and mechanical properties of high-strength flowable mortar reinforced with different percentages of palm fiber (0, 0.2, 0.4, 0.6, 0.8, 1.0, 1.2, 1.4, and 1.6% as volumetric fractions). The density, compressive strength, flexural strength, and toughness index were tested to determine the mechanical properties of this mortar. Test results illustrate that the inclusion of this fiber reduces the density of mortar. The use of 0.6% of palm fiber increases the compressive strength and flexural strength by about 15.1%, and 16%, respectively; besides, the toughness index (I5) of the high-strength flowable mortar has been significantly enhanced by the use of 1% and more of palm fiber.


2021 ◽  
Vol 879 ◽  
pp. 284-293
Author(s):  
Norliana Bakar ◽  
Siew Choo Chin

Fiber Reinforced Polymer (FRP) made from synthetic fiber had been widely used for strengthening of reinforced concrete (RC) structures in the past decades. Due to its high cost, detrimental to the environment and human health, natural fiber composites becoming the current alternatives towards a green and environmental friendly material. This paper presents an investigation on the mechanical properties of bamboo fiber reinforced composite (BFRC) with different types of resins. The BFRC specimens were prepared by hand lay-up method using epoxy and vinyl-ester resins. Bamboo fiber volume fractions, 30%, 35%, 40%, 45% and 50% was experimentally investigated by conducting tensile and flexural test, respectively. Results showed that the tensile and flexural strength of bamboo fiber reinforced epoxy composite (BFREC) was 63.2% greater than the bamboo fiber reinforced vinyl-ester composite (BFRVC). It was found that 45% of bamboo fiber volume fraction on BFREC exhibited the highest tensile strength compared to other BFRECs. Meanwhile, 40% bamboo fiber volume fraction of BFRVC showed the highest tensile strength between bamboo fiber volume fractions for BFRC using vinyl-ester resin. Studies showed that epoxy-based BFRC exhibited excellent results compared to the vinyl-ester-based composite. Further studies are required on using BFRC epoxy-based composite in various structural applications and strengthening purposes.


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