A Comparative Study on Performance of Synthetic and Natural Fibers on Compressive and Flexural Strength of Concrete

2020 ◽  
Vol 36 ◽  
pp. 97-113
Author(s):  
V ViswaTeja Turlapati ◽  
Ch. Vineel

Ordinary concrete - a stone like structure which is formed by the chemical reaction of the cement, aggregate and water and is a brittle material which is strong in compression but very weak in tension, which causes cracks under small loads. These cracks gradually propagate to the compression end of the member and finally, the member breaks. These increase in size and magnitude with time and finally fails. One of the successful reinforcing methods is providing steel reinforcement but even then, cracks in reinforced concrete members extend freely. Thus, need for multidirectional and closely spaced steel reinforcement arises. Fiber reinforcement gives the solution for this problem. So, to increase the tensile strength of ordinary concrete a technique of introduction of fibers in concrete is being used. These fibers act as crack arrestors and prevent the propagation of the cracks, improves the post cracking response of the concrete, i.e., to improve its energy absorption capacity and apparent ductility, and crack control. The Present study focuses upon, Synthetic (Polypropylene) Fiber Reinforcement (SFRC) of 1% and 3% and Natural (Jute) Fiber Reinforcement (NFRC) of 1% and 3% by weight and are compared with respect to their compressive strength and flexural strength. The present study concludes considering the practical issue of workability of fibers, that in between synthetic and natural fibers selected, 1% Polypropylene fibers can be added as a reinforcement to ordinary concrete to enhance both compressive strength by nearly 2 times at 28 days curing duration and flexural strength by 35%% at 28 days curing duration. History and Development

2014 ◽  
Vol 1033-1034 ◽  
pp. 1189-1193
Author(s):  
Lin Yang ◽  
Ya Ming Liu ◽  
Jian Zuo ◽  
Bin Zhang ◽  
Jian Xin Cao

Cement, phosphorus slag, silica sand, fly ash and water reducing agent were well-mixed, and then stirred with polypropylene fiber and water for preparation of phosphorus slag mortar. Performance of the mortar was tested according to relevant standards. The results showed that polypropylene fiber can improve flexural strength and tensile bond strength of the mortar. However the polypropylene fiber has little contribution to the compressive strength of the mortar. Fluidity of phosphorus slag mortar reduces with length of the fiber increasing. Polypropylene fibers distributed evenly in the phosphorus slag mortar can obstruct generation and propagation of micro cracks, thus crack-control property of mortar can be improved. When polypropylene fiber’s length and content are 10 mm and 4 g (by weight) respectively, the properties of phosphorus slag mortar are as follow: fluidity 209 mm, tensile bond strength 0.71 MPa, flexural strength 4.32 MPa, Compressive strength 10.83 MPa, and ratio of compressive strength to flexural strength 2.51 on 28 days.


2012 ◽  
Vol 174-177 ◽  
pp. 1299-1305
Author(s):  
Xun Liu ◽  
You Xin Jiang

Due to flaws of foamed concrete (e.g. low strength, high shrinkage and easily cracking), a new-type foamed concrete with high-strength and low-shrinkage was prepared using a combination of polypropylene fiber reinforcement and alunite expansive agent compensating shrinkage. Compared to conventional foamed concrete prepared under the same conditions, the modified foamed concrete with the optimal parameters has notable improvements: the 28 d shrinkage falls by 50 %, the compressive strength and flexural strength increase by 21.7 % and 37.5 %, respectively. A model is proposed to explain the mechanism of the co-action of PPF and AEA.


Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4778
Author(s):  
Carla Matthäus ◽  
Nadine Kofler ◽  
Thomas Kränkel ◽  
Daniel Weger ◽  
Christoph Gehlen

Lightweight mortar extrusion enables the production of monolithic exterior wall components with improved thermal insulation by installing air chambers and reduced material demand compared to conventional construction techniques. However, without reinforcement, the systems are not capable of bearing high flexural forces and, thus, the application possibilities are limited. Furthermore, the layer bonding is a weak spot in the system. We investigate a reinforcement strategy combining fibers in the mortar matrix with vertically inserted elements to compensate the layer bonding. By implementing fibers in the extruded matrix, the flexural strength can be increased almost threefold parallel to the layers. However, there is still an anisotropy between the layers as fibers are oriented during deposition and the layer bond is still mainly depending on hydration processes. This can be compensated by the vertical insertion of reinforcement elements in the freshly deposited layers. Corrugated wire fibers as well as short steel reinforcement elements were suitable to increase the flexural strength between the layers. As shown, the potential increase in flexural strength could be of a factor six compared to the reference (12 N/mm2 instead of 1.9 N/mm2). Thus, the presented methods reduce anisotropy in flexural strength due to layered production.


Materials ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 2937
Author(s):  
Huimin Chen ◽  
Chunyan Xie ◽  
Chao Fu ◽  
Jing Liu ◽  
Xiuli Wei ◽  
...  

Orthogonal test method was applied to analyze the strength properties of basalt-polypropylene mortar. The effect of basalt fiber length, polypropylene fiber length, basalt fiber volume content and polypropylene fiber volume content on the 28 d cube compressive strength and flexural strength were investigated. Test results show that comparing with flexural strength, the influence of basalt fiber length and polypropylene fiber length on compressive strength of mortar was greater than on flexural strength. The length of polypropylene fibers contributes the highest to the flexural strength. The effect of basalt fiber on mortar strength is the largest with 6 mm length and 4% content. Polypropylene fiber length has the greatest influence on the compressive strength of fiber mortar, followed by basalt fiber volume content. Volume content of polypropylene fiber has the greatest influence on flexural strength of fiber mortar, followed by polypropylene fiber length. According to the scoring of the efficacy coefficient method, the best ratio combination for compressive and flexural strength was the basalt fiber length of 9 mm, polypropylene fiber length of 6 mm, basalt fiber volume content of 4% and polypropylene fiber volume content of 4%. Compared with the blank samples, the 28 d compressive strength and 28 d flexural strength of the cement mortar samples were increased by 27.4% and 49% respectively. According to the test results, the properties of the fiber were analyzed and evaluated and the mechanism of fiber action and fiber microstructure were analyzed.


2011 ◽  
Vol 219-220 ◽  
pp. 1601-1607 ◽  
Author(s):  
Tammam Merhej ◽  
Xin Kai Li ◽  
De Cheng Feng

This paper presents the experimental investigation carried out to study the behavior of polypropylene fiber reinforced concrete (PPFRC) under compression and flexure. Crimped polypropylene fibers and twisted polypropylene fiber were used with 0.0%, 0.2%, 0.4% and 0.6% volume fractions. The influence of the volume fraction of each shape of polypropylene fiber on the compressive strength and flexural strength is presented. Empirical equations to predict the effect of polypropylene fiber on compressive and flexural strength of concrete were proposed using linear regression analysis. An increase of 27% in flexural strength was obtained when 0.6% volume fraction of twisted polypropylene fiber was added. It was also found that the contribution of fiber in flexural strength is more effective when twisted fibers were used. The compressive strength was found to be less affected by polypropylene fiber addition.


2011 ◽  
Vol 418-420 ◽  
pp. 441-444 ◽  
Author(s):  
Feng Lan Li ◽  
Yan Zeng ◽  
Chang Yong Li

Due to many different characteristics such as irregular polygon particle with pointed edges, rough surface and larger content of stone powder, machine-made sand has ignorable effects on the properties of concrete. As the basis for the design of concrete structures, the relations among the basic mechanical properties of concrete such as compressive strength, tensile strength, flexural strength and elastic modulus should be clearly understood. This paper summarizes the test data from the published references, and discusses the relations among these properties by statistical analyses compared with those of ordinary concrete. The results show that the axial compressive strength and the tensile strength can be prospected by the same formulas of ordinary concrete specified in current Chinese design code, but the prospected tensile strength should multiply a reducing coefficient when the strength grade of concrete is lower than C30. The elastic modulus of concrete with machine-made sand is larger than that of ordinary concrete, which should be prospect by the formula in this paper. Meanwhile, the formula of flexural strength is suggested.


2010 ◽  
Vol 168-170 ◽  
pp. 456-459
Author(s):  
Hai Yan Yuan ◽  
Shui Zhang ◽  
Guo Zhong Li

By adopting the method of orthogonal experimental design, the effect of three independent variables, that is steel fiber fraction, polypropylene fiber fraction and silica fume fraction on the compressive strength, flexural strength and shrinkage of cement mortar was studied. The results indicate that steel fiber is one of the most important factors affecting compressive strength and shrinkage, and polypropylene fiber is one of the most important factors affecting flexural strength and shrinkage of cement mortar. By using deviation analysis to analyze the orthogonal experiment results, the optimized mix proportion of hybrid fiber reinforced cement mortar is determined. The hybrid effect of steel fiber and polypropylene fiber on the properties of cement mortar is discussed.


2011 ◽  
Vol 346 ◽  
pp. 30-33
Author(s):  
Hong Wei Wang

A designed experimental study has been conducted to investigate the effect of polypropylene fiber on the compressive strength and flexural properties of concrete containing silica fume, a large number of experiments have been carried out in this study. The flexural properties include flexural strength and flexural modulus of elasticity. On the basis of the experimental results of the specimens of six sets of mix proportions, the mechanism of action of polypropylene fiber on compressive strength, flexural strength and flexural modulus of elasticity has been analyzed in details. The results indicate that there is a tendency of increase in the compressive strength and flexural strength, and the flexural modulus of elasticity of concrete containing silica fume decrease gradually with the increase of fiber volume fraction.


In this paper various mix proportions of Reactive Powder Concretes were formulated using ordinary Portland cement, Fly ash, Micro silica, Silica Fume, Quartz powder etc and these concretes were subjected to strength test. The best mix was selected for further in depth study with fibers like Sisal fiber, Coir fiber, Hair fiber and Polypropylene fiber mixed Reactive Powder Concrete and the various tests have been performed Cube Compressive strength, Cylinder Compressive strength, Flexural strength, Split Tensile strength, Shear test, Water absorption, Sorptivity and Chloride diffusion etc. As a result, fiber incorporated concrete shows increasing Flexural strength, splitting tensile strength, and shear strength up to 30% as compared to control RPC and gives minimal decrease in compressive strength by the addition of fibers. These characteristics make it as a promising material for casting non structural elements such as pressure pipes, flooring tiles, Partition panels, door and window frames. It can also be used as repair materials.


2020 ◽  
Vol 831 ◽  
pp. 110-114
Author(s):  
Riana Herlina Lumingkewas ◽  
Sigit Pranowo Hadiwardoyo ◽  
Abrar Husen ◽  
Saepudin

The development of nanotechnology continues to grow. The use of nanocement in concrete is expected to reduce the number of pores and improve hydration in concrete and provide more strength to the concrete. The use of natural fibers, in this case, coconut fiber can prevent cracks in concrete and make fiber concrete more ductile than ordinary concrete. The effect of using nanocement on coconut fiber concrete on the strength of the concrete to be studied. Methodology to complete the research objectives, use nanocement used in concrete, which has added coconut fiber. Tests reviewed the value of slump and specific gravity. Then, testing the compressive strength at 7, 24, 28 days. The results obtained were an increase of 48.19% in the strength of concrete. Further research needs to review on mixing nanocement with other natural fibers.


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