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Hydration characteristics of bagasse in cement-based composites

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https://www.eduzhai.net International Journal of Composite M aterials 2013, 3(1): 1-6 DOI: 10.5923/j.cmaterials.20130301.01 Hydration Characteristics of Bagasse in Cement-Bonded Composites Omoniyi T. E*, Akinyemi B. A Department of Agricultural and Environmental Engineering, University of Ibadan, Oyo State, Nigeria Abstract Four co mpatib ility assessment methods were used to ascertain the co mpatibility of bagasse with cement composite. The time to reach maximu m hydration temperature was achieved when CaCl2 and water above 60℃ were used as treatment agents. Maximu m hydration temperature between 55℃ – 61℃ were achieved when treated with 1 – 3% CaCl2. The inhibitory index value of 1.58% - 8.83% were achieved when treated with bagasse while others have value greater than the acceptable parameter standard for exterior use. The maximu m hydration rate of 4.0 was achieved when the bagasse fiber was treated with 3% CaCl2 and this was closely follo wed by 2% CaCl2 at 3.38. These results showed that all the different compatibility assessment parameters adopted indicated that bagasse was inco mpatible with Port land cement without pre-treat ment. Treat ment of bagasse with cold water and addition of 2% CaCl2 satisfied all requirements for co mpatibility in terms of time to reach maximu m temperature, the maximu m hydration temperature and the inhibitory index value. Treatment with CaCl2 gave the best result probably due to its capacity to minimize the adverse effect of the soluble sugars and extractives and also to accelerate cement hardening and setting. This result shows that treated bagasse is compatible with cement bonded composite for construction purposes. Keywords Hydration Index, Bagasse, Treatment, Temperature ,Time 1. Introduction Increasing attention should be given to the use of natural fibre with a view to conserving energy and protecting the environment and because of basic engineering properties of crack resistance, duct ility and energy absorpt ion that it impacts on cement particleboard (CPB). In the past, wood was th e main agg reg at e emp loy ed in CPB. Ho wev er economic and environ mental p ressures have led to other lig no cellu loses b ein g co ns idered fo r use. A rang e o f s ubs t itu te mat erials , s uch as ag ricu lt u ral and wo od processing residues, tree barks and weeds, has been tested. Examples include rice straw and giant ipil-ip il, oil palm shell and cork granules[1]. Several other candidates are available, in clud ing ratt an cane, co conut hus k, b anan a, b agasse, bamboo, and oil palm. Th ese materials are availab le in abundance and present as waste in West Africa. Natu ral fibres cement co mposite is useful because of eco-friendly nature and provide the most economic and socially useful outlet for natural fibre chips, residues and agricultural wastes. Coconut is one of the most economically useful palms in tropical Asia and Africa[2]. All parts of the palm are useful and local people use it for lu mber and as source of food. Coconut husk however is of limited co mmercial use at p res en t. Rattan, a non timber forest product used for manufacturing cane furn iture, gro ws as a spiny climber in the tropics and sub-tropics. Follo wing harvesting, rattan is stripped of its spines and leaf sheaths before drying. Unfortunately much of the cane material becomes discoloured by staining fungi during this part of the process[1]. This material cannot be processed for furn iture and is considered waste. At present 20 – 30 % of the processed rattan is waste. The major challenges facing the development of durable natural fibre cement co mposite are the inherent weakness of the natural fibre part icles themselves such as low elastic modulus, high water absorption, susceptibility to fungal and insect attack and lack of durability in alkaline environ ment. And also because of the influence of botanical co mponents (hemi-cellulose, starch, tannin, phenols, and lignin) all which are known to inhibit the normal setting and strength development properties of cement matrix. Th is work examines the compatibility o f bagasse with ordinary Portland cement using hydration tests. 2. Materials and Methods * Corresponding author: temidayoomoniyi@gmail.com (Omoniyi T. E) Published online at https://www.eduzhai.net Copyright © 2013 Scientific & Academic Publishing. All Rights Reserved The hydration test method used was the same as described by[3] and[4] . This test investigated the suitability of bagasse in wood-cement manufacture. Bagasse was hammer-milled, 2 Omoniyi T. E et al.: Hydration Characteristics of Bagasse in Cement-Bonded Composites sieved and dried for two weeks. Only part icles that passed through 850 μm sieve and retained on a 600 μm were used. The bagasse/water/cement mixtures co mprised 15 g bagasse particles, 200 g ord inary Portland cement and 90.5 ml distilled water (as in[5] and[2] ). Each 15g bagasse sample was gradually mixed with 200g of cement in a polythene bag thereafter distilled water was added to the mixture and stirred until homogenous paste was obtained. Required quantity of CaCl2 (at four concentrations by weight 0, 1, 2, and 3% respectively) were added to the paste. The mixture was transferred to a De war flask and a thermocouple was inserted to enable temperature measurement at 1 – min intervals over a 23 – h period. The time taken to attain maximu m temperature was assessed. Three rep licates were used. The experiments were carried out at room temperature of 25 ± 2 ℃ . The same procedure was followed for bagasse pre-treated with cold and hot water. To calculate the inhibitory index (l), the following equation was used: I =  ( t 2 − t ' 2 t ' 2 ) × ( T2' − T2' T2 ) × ( S ' 2 − S ' 2 S 2 ) ×100 [6] Where: t2 is the time to reach maximu m temperature of the inhibited cement (bagasse-cementwater mixtu re ) t’2 is the time to reach maximu m temperature of the uninhibited cement (cement-water mixture) T2 is the maximu m hydration temperature of the inhib ited cement (bagasse-cement-water mixture) T’2 is the maximu m hydration temperature of the uninhibited cement (cement-water mixture) S2 is the maximu m temperature – time slope of the inhibited cement (bagasse-cement-water mixture) S’2 is the maximu m temperature – time slope of the uninhibited cement (cement-water mixture). 3. Results and Discussion 3.1. Hydration Test Results 3.1.1. Time Taken by the Bagasse-Cement to Attain Maximu m Temperature Table 1. Influence of Treatments on the Hydration Behaviour of the Bagasse-Cement Composite Parameters Levels of compatibility Particle/Cement Mixture t(h) T max I (%) R Ct CTmax CI CR Untreated Bagasse Bagasse and Cold Water Bagasse + Water at 500C 18 40 47.5 0.56 U U 14 47 30.2 1.2 S U 13 48 25.17 1.38 S U MI L MI L MI L Bagasse + Water at 600C Bagasse + Water at 700C Bagasse + Water at 800C Bagasse + 1% CaCl2 Bagasse + 2% CaCl2 Bagasse + 3% CaCl2 Clean Cement Paste Cement and Sand 12 48 21.57 1.5 S U MI L 12 48 19.39 1.5 S U MI L 11 49 17.04 1.73 S U MI L 10 55 8.83 2.5 S IS C M 8 61 1.58 3.88 S S C H 7 58 1.98 4.0 S IS C H 6 66 7 63 The effects of pre-treat ments on the hydration behaviour untreated bagasse-cement mixture about 18 hours to attain of the bagasse-cement are presented in Table 1. It took the maximu m hydration temperature as opposed to 14 hours for 4 Omoniyi T. E et al.: Hydration Characteristics of Bagasse in Cement-Bonded Composites the bagasse soaked in cold water for 48 hours. The equivalent time to attain maximu m hydration temperature for neat cement was 6 hours and 7 hours for cement mixed with sand. Using the time to attain maximu m hydration temperature parameter alone as measure of compatibility, untreated bagasse could be considered unsuitable, since it took more than 15 h to attain its maximu m hydration temperature. Aggregate/cement/water systems that attain maximu m hydration temperature in less than 15 h are considered suitable, while those that require more than 20 h are considered inhibitory[7]. The addition of CaCl2 at different levels improved the time taken to attain maximu m temperature by the mixtures. The best result was obtained with the addition of 2% CaCl2. In this case, the time to attain maximu m temperature reduced fro m 18 h (untreated bagasse) to 7 h (about 62% reduction). A close examinat ion of Table 1 shows that CaCl2 was more effective in reducing the time to attain maximu m temperature. 3.1.2. Maximu m Hydration Temperatures of the Mixtures The maximu m hydration temperatures (Tmax) of the different aggregate-cement mixtures are shown in Table 1. The values ranged from 400C for the untreated bagasse/cement/sand mixture to 660C for neat cement. Using Tmax as the criterion for co mpatibility, the cold and hot water treated mixture could be considered unsuitable for cement board production since they reduced hydration temperature to values below 500C, the value reco mmended by[8] , and[9] . Addition of 1% and 3% CaCl2 however increased Tmax fro m 40℃ for the untreated bagasse/cement mixtu re to 55℃ and 61℃respectively. t = time to reach maximu m temperature Tmax = maximu m hydration temperature of the inhibited cement. T’max = maximu m hydration temperature of the uninhibited cement. I = inhib itory index R = hydration rate Ct = co mpatibility level based on time to maximu m temperature CTmax = co mpatib ility leve l based on ma ximu m hydration temperature CI = compat ibility level based on inhibitory inde x CR = co mpatibility level based on hydration rate C = co mpatib le; S = suitable; U = unsuitable; IS = intermediately suitable; MI = moderately inhibitory; L = low; M = med iu m; H = high hydration rate Temperature (oC) o 65 60 55 50 45 40 35 30 0 2 4 6 8 10 12 14 16 18 20 22 24 Time (Hours) CaCl2 at 1% CaCl2 at 2% CaCl2 at 3% Fi gure 1. Effect s of Chemical Treatment s at Different Levels of CaCl2 Concent rat ion on Hydrat ion Behaviour of Bagasse Composite Temperature (oC) International Journal of Composite M aterials 2013, 3(1): 1-6 5 65 60 55 50 45 40 35 30 0 3 6 9 12 15 18 21 24 Time (hours) Clean cement paste Cement + sand C+S Untreated bagasse C+S+Cold water treated bagase Figure 2. Effects of Cold Water Treatment on Hydration Behaviour of Bagasse Composite 70 65 60 55 50 45 40 35 30 0 4 8 12 16 20 24 Time (Hours) Clean cement paste Untreated bagasse-cement composite Treated bagassecement composite Temperature (oC) Fi gure 3. Effect s of Chemical Treatment on Hydration Behaviour of Bagasse Composite 6 Omoniyi T. E et al.: Hydration Characteristics of Bagasse in Cement-Bonded Composites 50 Temperature (oC) 45 50oC 60oC 40 70oC 80oC 35 30 0 3 6 9 12 15 18 21 24 Time (Hours) Fi gure 4. Effect s of Hot Wat er Treat ment on Hydrat ion Behaviour of Bagasse Cement Composit e 3.2. Inhi bi tory Index The inhibitory index (I) values for the different treat ments are shown in Table 1. The values ranged fro m 1.58% for bagasse treated with 2% CaCl2 to 47.50% for the untreated bagasse cement mixture. The untreated bagasse-cement/sand mixtu re that had the longest time (18 h ) to maximu m temperature and lowest hydration temperature value (400C) also had the highest I value of 47.5% and the least hydration rate of 0.56. These results show that all the different compatibility assessment parameters adopted indicated that the bagasse was incompatible with Portland cement without pre-treat ment. Treat ment of bagasse with cold water and addition of 2% CaCl2 satisfied all requirements for compatibility in terms of time to reach maximu m temperature, the maximu m hydration temperature and the inhibitory index value. Treat ment with CaCl2 gave the best result probably due to its capacity to minimize the adverse effect of the soluble sugars and extractives and also to accelerate cement hardening and setting. Co mparable data in the literature for the inhib ition index of bagasse flakes and particles in cement matrices were not found. Other wood species in mixture with cement that gave moderate inhibition similar to bagasse include Eucalyptus[10], Cypress[4] and Pseudoacacia[8]. Summary and Concl usion: Hydration characteristics of bagasse cement composite have been determined. The influence of compatibility based on time, temperatures, hydration index and rate were examined for different treatments. It was concluded that bagasse treated with CaCl2 at 2% is compatib le with ordinary Portland cement. The follo wing conclusions were drawn fro m the hydration tes t; 1. Untreated bagasse is not compatible with ordinary Portland cement. 2. Addition of 2% CaCl2 improved the temperature and reduced the setting time. 3. Addition of 2% CaCl2 also gave the least inhibitory index and the highest hydration rate. This showed that when bagasse cement composite is treated with 2% CaCl2 the result is compatible and suitable for construction purposes. REFERENCES [1] Olorunnisola, A.O. Pitman, A. and M ansfield-William H. (2005). Strength Properties and Potential Uses of Rattan-Cement Composites. Journal of Bamboo and Rattan Vol. 4 (4) pp. 343 – 352. [2] Olorunnisola, A.O. Pitman, A. and M ansfield-William H. (2005). Hydration Characteristics of Cement-bonded Composites made from Rattan Cane and Coconut Husk. Journal of Bamboo and Rattan, 4 ( 2) pp. 193-201. [3] Hosfstrand, A.D.; Moslemi, A.A.; Garcia, J.F. (1984). Curing characteristics of wood particles from nikne northen Rocky M ountain Species mixed with Portland cement. Forest International Journal of Composite M aterials 2013, 3(1): 1-6 7 Products Journal 34 (2) : 57 – 61. M aderas Ciencia tecnologia, 10 (2) 93 – 98. [4] Okino, E.Y.A.; De Souza, M .R.; Santana, M .A.E.; Da Alves, M .V.; De Souza, M .E.; Texeira, D.E. (2005). Physico-mechanical Properties and Decay Resistance Of Cupressus ssp Cement-Bonded Particleboards. Cement and Concrete Composites 27: pp. 333 – 338. [8] Semple, K.E. and Evans, P.D. (2004). Wood-Cement Composites – Suitability of Western Australian M allee Eucalypt, Blue Gum and M elaleucas. A Report for the RIRDC/Land and Water Australia/FWPRDC/M DBC Joint Venture Agroforestry Program. [5] M oslemi, A.A. Garcia, J.F. and Hofstrand, A.D. (1983): An [9] Wei, Y.M .; Zhou, Y.G. and Tomita, B. (2000). Study of Evaluation of the rate of Heat Evolution of Portland Cement – Hydration Behaviour of Wood Cement-based Composite II: Northern Rocky M ountain spp. Wood Fibre and Science Effect of Chemical Additives on the Hydration 15(2). 164-176. Characteristics and Strengths of Wood-Cement Composites. [6] Papadopoulos, A.N. (2007). An Investigation of the Suitability of Some Greek Wood Species in Wood Cement The Japan Wood Research Society Journal, Vol. 46 (2000) pp. 444 – 451. Composites M anufacture. Springer Vertage Holz Roh Werkst [10] Okino, E.Y.A.; De Souza, M .R.; Santana, M .A.E.; Da Alves, (2007) 65 (245-246). M .V.; De Souza, M .E.; Texeira, D.E. (2004). [7] Papadopoulos, A.N. (2008). Natural Durability and Performance of Hornbeam Cement Bonded Particleboard. Cement-Bonded wood Particleboard with a mixture of eucalypt and rubberwood. Cement and Concrete Composites 26: pp. 729 – 734.

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