Experimental Research on Mechanical Properties of Basalt Fiber Reinforced Concrete
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Journal of Critical Reviews ISSN- 2394-5125 Vol 7, Issue 13, 2020 EXPERIMENTAL RESEARCH ON MECHANICAL PROPERTIES OF BASALT FIBER REINFORCED CONCRETE P.Manibalan1 , R.Baskar2 1Research Scholar, Dept of Structural Engineering, Annamalai University, Tamilnadu, India 2 Professor, Dept of Structural Engineering, Annamalai University, Tamilnadu, India Received: 11.04.2020 Revised: 12.05.2020 Accepted: 08.06.2020 Abstract Basalt fiber was a type of natural fiber which exhibit a recent demand in research field due to better chemical resistance, better environment friendliness and recyclability. Concrete were cast and designed for M40 grade and incorporated a basalt fiber in various proportion such as 0, 0.3, 0.6, 0.9 and 1%. The main scope of the research is to determine the optimum content of basalt fibre which enhances the mechanical strength of concrete. Compressive strength, split tensile strength and flexural strength of basalt fiber reinforced concrete was tested and compared with the control concrete. Test result indicated the significant improvement in compressive strength and high magnitude improvement in flexural and split tensile strength were obtained by using basalt fiber even at low contents. Keywords: Low content of Basalt fiber, compressive strength, split tensile strength, flexural strength and optimum content. © 2020 by Advance Scientific Research. This is an open-access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/) DOI: http://dx.doi.org/10.31838/jcr.07.13.61 INTRODUCTION basalt fiber of 0.3 -0.5% in the volume fraction of concrete, Concrete is the man-made material which lasts for thousands of improved the compressive, flexural and tensile strength [9-10]. years. About 10 billion tons of concrete are produced every year and it is the second most consumed substance in the world. M40 grade of standard concrete were analyzed with Globally, it is proved that the usage of concrete is twice that of incorporating basalt fiber in volume fraction and determine its steel, wood, plastic and aluminum combined. But, since concrete optimum range. The dispersion of basalt fiber is based on the is weak in compression, reinforcement is required to withstand fiber aspect ratio and this aspect ratio is also play a siginificant the tensile force when a structural member is subjected to role in strength of concrete. bending. Fiber-reinforced concrete was concrete is a concept of adding fibers to the concrete to meet with the general deficiencies to tensile strength, impact strength, fatigue, brittleness, ductility and durability. The fibers include natural fiber, synthetic fiber, glass, asbestos, carbon, organic, etc., which acts as a micro reinforcement improving its structural strength and cohesion [1]. This micro reinforcement depends on the dimensions of the fiber such as its length and diameter, its aspect ratio (diameter/length), percentage proportioning of fibers to be added on to the concrete, the direction at which the fiber to be placed and condition of mixing, etc., The major role of fibers in FRC is that they delay and arrest the crack propagation to Fig 1 Basalt fiber certain extent than the conventional concrete. It was a composite obtained by adding thread-like structures that are long, thin and EXPERIMENTAL STUDY flexible which is classified based on their source such as natural Material and mixture proportion and synthetic fiber. OPC 53 grade analogous to ASTM Type I cement were used in concrete mixture and its material property were checked in Basalt fiber shown in figure 1 is one of the natural fibers because laboratory as the specific gravity of 3.15. The gravel of 20mm it will be extracted from the basalt rock. The only crushed rock to size and free from impurities were used as a coarse aggregate. be used in the manufacturing of a fiber is the basalt fiber. The The river sand that pass through 4.75 mm sieve and retains on fiber is obtained by melting the igneous basalt rock for about 0.075 mm sieve were used as fine aggregate. Salt free water is 2,700° F. Basalt fiber has high modulus of elasticity than glass used for mixing the concrete since the presence of salt in water fiber so it acts as better replacement of glass rebar in the for concrete mix leads to decrease in strength and durability of concrete beam [2]. It is good resistance to salt, alkalies, impact concrete to a large extent. The length and diameter of basalt fiber load and fire. so, it enhances the mechanical and impact strength is also playing a significant improvement in the concrete than the carbon fiber concrete. [3–5]. strength. For this study, the basalt fiber of 6mm length is used Thermal resistance and high corrosion character of basalt fiber and it is added in various proportion such as BF0.3, BF0.6, BF0.9 improved the strength and strain capacity of concrete [6-7]. The and BF1 in the volume of concrete. In this research, the alphabet length and volume of fiber is increased for the enhancing the BF represents the basalt fiber concrete and 0.3, 0.6, 0.9 and 1 mechanical properties of concrete [8]. Research stated that the behind the BF shows the fiber percentage in volume fraction and the mix proportioning are tabulated in table 1 Journal of critical reviews 353 EXPERIMENTAL RESEARCH ON MECHANICAL PROPERTIES OF BASALT FIBER REINFORCED CONCRETE Table 1 Mixing proportion for 1m3 Mixture W/B Water Cement Fine Coarse Volume Fiber (Kg/m3) (Kg/m3) Aggregate Aggregate Fraction (Vf) (Kg/m3) (Kg/m3) (Kg/m3) M40 (0%) 0.40 160 400 660 1168 0 0 M40 (0.3%) 0.40 160 400 660 1168 0.3 7.9 M40 (0.6%) 0.40 160 400 660 1168 0.6 15.9 M40 (0.9%) 0.40 160 400 660 1168 0.9 23.8 M40 (1%) 0.40 160 400 660 1168 1 26.5 Mixing and curing strength is the same that of the compression strength test with Proper mixing of concrete and curing has to be done for the the difference of applying tensile load instead of compressive proper and accurate results. Dry mix involves cement and fine load. Similarly, the load is gradually increased till the specimen aggregate for one minute, then followed by coarse aggregate for fails and the corresponding load represents the ultimate load. another one minute. The proper care was taken in dry mixing The split tensile strength can be obtained by dividing twice the due to the hand mixer. Further, fiber was added based on their load taken by the cylindrical specimen to its circumference which proportion and continued the dry mixing until it dispersed can be formulated as, evenly. Finally, water was added slowly and evenly to the mixture. The plastic state of concrete was mixed for 5 minutes to ft= 2P/πDL ensure the proper workability and distribution of fiber. The Where, P is the load at which the cylindrical specimen fails, D is plastic concrete was cast in 150mm3 cube for compressive the diameter of cylinder and L is the height of cylinder. strength test, 150mm×300mm cylinder for split tensile strength test and 100mm×100mm×500mm prism for flexural strength Flexural Strength test of concrete. Then, all the specimens were removed from the A prism specimen of dimensions width 100mm, depth 100mm mould after 24 hours of casting. The specimen was cured in the and length 500mm is used for the test. The flexural strength test water tank to complete the hydration of cement particles for was done on the 1000kN capacity flexural testing machine as per desired time period. In this study, each value is considered by the IS:516-1959. The testing machine consists of two steel rollers average of three repeated tests. over which the specimen is placed. The cured prism specimen is dried, cleaned and placed over the rollers properly. The load is EXPERIMENTAL TEST SETUP applied gradually and the load of failure of the prism is observed. Compressive Strength The flexural strength represents the modulus of rupture of the The compressive strength test as per IS:516-1959 was conducted concrete specimen which is given by the below formula, on the universal compression testing machine whose capacity is 3000kN. The test was carried out on 150mm3 cube specimens fr= PL/BD2 having three specimens for each proportion of concrete mix after Where, P is the maximum load the prism carries, L is the prism 28 days of curing period. The cube specimen was taken out from span, B is the prism width and D is the prism depth the curing, dried, cleaned and placed between the base plate and loading plate. The compressive load is applied uniformly onto the TEST RESULT AND DISCUSSION surface of the specimen. Then, the load is gradually increased till Compressive Strength the specimen breaks. The load at which the specimen fails is the Figure 2 depicts the variation of strength in compression of ultimate load taken by that concrete mix. The compressive basalt and control concrete. BF 0.3 shows the significant impact strength can be obtained from the below formula, of fiber inclusion was observed. However, the addition of fiber fc= P/A above 0.3% obtained the greater influence of compressive strength. From table 2, it is clear that the BF 0.9 concrete showed where, P is the Ultimate Load at which the specimen fails and A is the highest strength in compression than other concrete mix the Cross-sectional area proportions and conventional concrete. The increase in compressive strength of BF 0.9 concrete is 30% greater than the Split Tensile Strength control concrete. From this above observation, it is clearly The cylinder specimen of diameter 150mm and of height 300mm exhibited that basalt fiber’s optimum content is 0.9% in total is used for the testing of split tensile strength of concrete.