Experimental Properties Evaluation of Fiber Reinforced Concrete related to Canal-lining

Abstract

Seepage is a major water loss from the canal as compared to the other forms of water losses. So, it becomes important to reduce this seepage loss to increase the conveyance efficiency. Concrete is commonly used for canal-lining to reduce seepage loss since concrete materials are usually available in the vicinities of the local farmers. Considerable seepage (15%-20%) has been observed even in the cement–concrete conventional sections. Concrete lining structure is identical to thin plate in which cracking occurrence is frequent. The performance of canals decreases with an increase in the rate of cracking in concrete canal-lining. The rate of cracking in canal-lining can be reduced by improving the flexure, compressive, and splitting-tensile strengths of concrete. Out of these, splitting-tensile strength of concrete plays a vital role in controlling cracks. The use of fibers for characteristics improvement of concrete is very ancient. Natural fibers include many benefits, like low cost due to its abundance, least health hazards, and flexibility. The use of synthetic fibers as reinforcement in matrix has also attained intentness by reasons of its high strength, less water absorption, and low density in nature. The overall aim of the research program is to explore materials for better performance of canal-lining in terms of reduced water losses by controlling its rate of cracking due to alternate wetting and drying, and due to differential settlement, etc. The purpose of this work is to examine experimental behaviors of jute fiber reinforced concrete (JFRC), nylon fiber reinforced concrete (NFRC), and polypropylene fiber reinforced concrete (PPFRC) for controlling the rate of cracking in canal-lining. For this purpose, the mechanical properties, water absorption, and linear shrinkage of JFRC, NFRC, and PPFRC are determined experimentally as per ASTM standards. The properties of plain concrete (PC) are used as reference. The proportion of 1:3:1.5:0.7 (cement: sand: aggregate: water) is used for PC mix. The mixes of JFRC, NFRC, and PPFRC are manufactured by adding the JF, NF, and PPF, respectively, in the same mix design as that of PC. For production of each type of fiber reinforced composite (FRC), respective fibers having length of 50 mm are added in concrete by an amount of 5% (by mass of cement). The specimens of both PC and FRCs were tested in the fresh and solid state. The FRCs were less workable when contrasted with PC for the same W/C ratio. Thus, the slumps of xix JFRC, NFRC, and PPFRC were reduced by 61%, 36%, and 39%, respectively, than that of PC. As compared to compressive strength (CS) of PC, the CS of JFRC and NFRC decreased by 36% and 31%, respectively, and that of PPFRC improved by 1%. As compared to splitting-tensile strength (SS) of PC, the SS of JFRC and NFRC showed a decrease of 19% and 10%, respectively, and an improvement of 5% is observed in SS of PPFRC. An improvement of 8%, 10%, and 34% is observed in modulus of rupture of JFRC, NFRC, and PPFRC, respectively, as compared to that of PC. An increase of 87%, 127%, and 107% is observed in compressive total absorbed energy of JFRC, NFRC, and PPFRC, respectively, than that of PC. As compared to splitting-tensile total absorbed energy (STE) of PC, a decrease of 37% and 21% is observed in STE of JFRC and NFRC, respectively, and an increase of 11% is observed in the STE of PPFRC. And an increase of 53%, 68%, and 100%, in flexural total absorbed energy of JFRC, NFRC, and PPFRC, respectively, in comparison to that of PC. The enhancement of 124%, 127%, and 148% is observed in compressive toughness index of JFRC, NFRC, and PPFRC, respectively, than that of PC. An enhancement of 2%, 2%, and 3% is observed in splitting-tensile toughness index of JFRC, NFRC, and PPFRC, respectively, than that of PC. And by comparing to that of PC, an enhancement of 86%, 91%, and 94% is noticed in flexural toughness index of JFRC, NFRC, and PPFRC, respectively. As compared to PC, an increase of 8% and 1% is observed in water absorption (WA) of JFRC and NFRC, respectively, and a decrease of 4% is observed in the WA of PPFRC. Linear shrinkage ‘LS’ (% decrease) of JFRC and NFRC is 67% and 30%, respectively, more than that of PC. While LS (% decrease) of PPFRC is 15% less than that of PC. Empirical relations have been developed with the help of experimental data for prediction of WA and LS. The relationship between WA/LS and each of the CS, SS, SPE, and FPE are made because of their observed mutual coherence in experimental outcomes. There is a good agreement between the experimental and empirical values. The percentage error is 0.4%-20%. Among the tested FRCs, PPFRC showed the better performance. This may ensure to control the rate of cracking in canal-lining, ultimately improving its performance.