APPLICATION OF DIGITAL CELLULAR RADIO FOR MOBILE LOCATION ESTIMATION IIUM Engineering Journal, Vol. 21, No. 2, 2020 Wan Ibrahim et al. https://doi.org/10.31436/iiumej.v21i2.1285 INFLUENCE OF PALM OIL BIOMASS CLINKER AND EMPTY FRUIT BUNCH FIBERS ON CONCRETE PROPERTIES MOHD HAZIMAN WAN IBRAHIM1*, SAJJAD ALI MANGI2, SHARIFAH SALWA MOHD ZUKI1, RAMADHANSYAH PUTRA JAYA3, DADANG SUPRIYATNO4 1 Jamilus Research Center, Faculty of Civil Engineering and Built Environment, Universiti Tun Hussein Onn Malaysia, 86400, Parit Raja, Johor, Malaysia. 2 Department of Civil Engineering, Mehran University of Engineering and Technology, SZAB Campus Khairpur Mir’s, Sindh, Pakistan. 3 Department of Civil Engineering, College of Engineering, Universiti Malaysia Pahang, 26300, Kuantan, Pahang, Malaysia. 4 Faculty of Engineering, Universitas Negeri Surabaya, Indonesia. * Corresponding author: haziman@uthm.edu.my (Received: 3 rd November 2019; Accepted: 22 nd March 2020; Published on-line: 4 th July 2020) ABSTRACT: This study aims to evaluate the influence of palm oil Empty F r ui t Bunch (EFB) fibers on flexural strength performance of concrete in the presence of Palm Oil Biomass Clinker (POBC). This study considered various proportions of palm oil EFB fibers as 0%, 0.2%, 0.4%, and 0.6% in concrete with fixed amount of POBC as 10% . I t was investigated that there is substantial influence of palm oil EFB fibers on pr oper t i es of concrete containing 10% POBC as sand replacement. The experimental findings of this study indicated that the workability of fresh mix concrete decreases as palm oil E F B fiber content increased. Besides that, hardened properties of concrete were found to be improved as the amount of palm oil EFB fibers increased in the concrete. It was not i ced that flexural strength was improved with addition of 0.2% palm oil EFB fibers that act as reinforcement and deliver growth in flexural strength for concrete containing 10% of POBC. Hence, it was concluded that palm oil EFB fiber could be utilized as fiber reinforcement in concrete to improve flexural strength performance of the concrete. ABSTRAK: Kajian ini bertujuan mengkaji pengaruh gentian tandan kelapa sawit ( E F B) terhadap kekuatan lentur pada konkrit dengan kehadiran klinker minyak kelapa sawit biomas (POBC). Kajian ini mengguna pakai pelbagai peratus serat EFB kelapa sawit dalam konkrit iaitu sebanyak 0%, 0.2%, 0.4%, dan 0.6% dengan jumlah tetap POBC sebanyak 10%. Didapati bahawa gentian tandan kelapa sawit EFB yang mengandungi 10% POBC berpengaruh besar sebagai pengganti pasir dalam bahan konkrit. P enem uan eksperimen menunjukkan bahawa kebolehkerjaan campuran baru konkrit berkurangan apabila kandungan gentian EFB minyak sawit meningkat. Selain itu, sifat-sifat mengeras pada konkrit didapati bertambah baik apabila jumlah gentian EFB minyak sawit meningkat dalam konkrit. Di samping itu, kekuatan lenturan meningkat dengan penambahan sebanyak 0.2% serat EFB minyak kelapa sawit, berfungsi sebagai penguat dan penambah kekuatan lenturan pada konkrit yang mengandung 10% POBC. Ol eh i t u, serat EFB minyak kelapa sawit boleh digunakan sebagai penguat gentian dalam konkr i t bagi meningkatkan kekuatan lenturan konkrit. KEYWORDS: bunch fiber; biomass clinker; compressive strength; flexural strength 100 mailto:haziman@uthm.edu.my IIUM Engineering Journal, Vol. 21, No. 2, 2020 Wan Ibrahim et al. https://doi.org/10.31436/iiumej.v21i2.1285 1. INTRODUCTION The production of palm oil has been increased over the years. According to a re c e n t report by the Malaysia Palm Oil Board (MPOB), crude palm oil production has incre a se d from 24.91 to 28.64 million tons in a year [1]. This huge quantity of palm oil p ro d uc tio n left behind the waste by-products known as Palm Oil Biomass Clinker (POBC) a n d p a lm oil Empty Fruit Bunch (EFB). In Malaysia, EFB is being utilized as a fertilizer for the agricultural field and POBC is being considered in concrete as cement and sand replacement material. POBC is a waste material produced through incineration of oil palm shells and mesocarp fiber as fuel for stream turbines in mills [2]. A mass iv e q u a n tity o f POBC is usually dumped into landfills, which causes environmental problems. H o w ev e r, use of sustainable materials should be given immediate attention and emphasis on the sustainable development through adopting waste by -products into the potential construction material [3]. The POBC has a lower value of specific gravity and higher crushing value, which indicates its potentiality to be considered as an alternative source of fine aggregate. Th e re is no pre-treatment or modification required for this material. The ad op tio n o f PO BC a s fine aggregate to some extent could save the depletion of natural resources [2]. Recent study was conducted by Wan Ibrahim et al. [4] on POBC as fine aggregate replacement in concrete with hooked-end steel fibers. They considered a 10% proportion of PO BC to b e an optimum replacement level of fine aggregates in concrete. However, th is m e th o d c a n reduce the self -weight of concrete, which delivers lightweight and green and s u s ta in ab le concrete. Beside that palm oil EFB fiber is one of the local natural fibers, which can easily be obtained at low cost and low level of energy either in manpower or technology. Henc e, this study aims to investigate the influence of palm oil EFB fiber on the fresh and hardened concrete properties with 10% POBC as fine aggregate. 2. PREVIOUS RELATED RESEARCH 2.1 Effects of POBC on Concrete Properties Concrete containing POBC as fine aggregate is influenced by the physical prope rtie s of POBA. However, POBC is a porous material that absorbs more water than normal aggregates, its water absorption was noted in the range of 4.7-26.5%, wh ic h d e liv e r lo w workability concrete [5]. It was also declared by Ahmmad, et al. [6] that lightweight concrete can integrate more waste materials like crushed Oil Palm Shell (OPS) a s c o a rs e aggregate and Palm Oil Clinker (POC) as a replacement of fine aggregate. They d e c la red that the modulus of elasticity was 23% higher in OPS concrete. The lower compressive strength of self -compacting concrete was observed when fully or partially coarse and f in e aggregate were replaced with POC [2]. Gunasekaran et al. [7] considered Coconut Shell Concrete (CSC). They declare d th a t workability and tensile and flexural strength were improved. Overall, CSC bond s tre ngth is comparable to that of normal and lightweight aggregate concretes. However, they further declared that coconut shells fulfil the provisions to be used as aggregate for lightweight concrete. Abutaha et al. [8] investigated the compressive strength of concrete with Palm Oil Clinker (POC) as coarse and fine aggregate. They declared that the amount of POC in th e mix reduces the compressive strength of the concrete as shown in Fig. 1, which shows that the targeted compressive strength of Grade 40 concrete was achievable with 1 0 % c o ars e aggregate replacement with POC. The strength declined by 11.73%, 16.79%, 18.94%, 101 IIUM Engineering Journal, Vol. 21, No. 2, 2020 Wan Ibrahim et al. https://doi.org/10.31436/iiumej.v21i2.1285 19.66%, 21.60% and 30.37% at the replacement levels of 10%, 20%, 40%, 60%, 80% an d 100% respectively. The maximum drop of strength was noticed with full re p la c em e nt o f coarse aggregate. Nevertheless, the compressive strength performance of concrete with POC as fine aggregate is far better than coarse aggregate replace ment. It was observed that POC as fine aggregate can enhance the compressive strength as shown in Fig. 2. It indicated that at the replacement level of 10%, 20%, 40%, 60% and 100% the compressive strength was noticed as decreased by 4.07%, 4.43%, 0.15%, 0.80%, and 5.17%, respectively. However, compressive strength was found to be 5% improved at 80% replacement. These results show the potentiality of POC to be utilized as re p la c e m e nt o f fine aggregate. Therefore, this study also considered the 10% replacement. Fig. 1: Concrete strength performance with POC as replacement of coarse aggregates [8]. . Fig. 2: Concrete strength performance with POC as replacement of fine aggregates [8]. Furthermore, Shahreen et al. [9] examined the flexural strength of concrete comprising POC as fine aggregate replacement. It showed a positive increment in flexura l strength at early ages due to the presence of POC fine particles, which creates a pozzolanic reaction and densification of the concrete mix and enhanced internal bond s among aggregates and cement paste, resulting in the development of strength as seen in the results provided in Fig. 3. They declared that fine particles of POC occup y the free space s in th e 102 IIUM Engineering Journal, Vol. 21, No. 2, 2020 Wan Ibrahim et al. https://doi.org/10.31436/iiumej.v21i2.1285 concrete and fill the voids, which delivers high density and increases the s ta b ility o f th e concrete mix. It was noticed that the flexural strength of concrete wa s in c re a se d a rou nd 28% and 33% with incorporation of 5% and 10% of POBC as fine aggregates , respectively [9]. However, the opposite results were found with more than 10% of POBC [10]. The adverse influence was noticed with the utilization of POBC as coarse and fine aggre ga te s in concrete. Fig. 3: Flexural strength result of POC concrete and conventio nal concrete [9]. From the literature review it can be concluded that the presence of POBC c a n a f fec t the performance of concrete. Therefore, the flexural strength performance would be improved with the addition of fiber along with the 10% proportion of POBC as fine aggregate replacement. 2.2 Effects of Natural Fiber to Concrete Particularly in tropical states like Malaysia and Indonesia, palm oil EFB are the abundant waste that is left behind after the fruits are stripped from fruit bunches f or the oil extraction process [11]. EFB fiber is a type of fiber that is clean and free from pes tic id es . This fiber could be utilized in concrete to improve its performance. It was previously w e ll known that the inclusion of fibers in concrete creates reinforced concrete that delivers better strength than normal concrete. For instance , previous research work has been summarized below on the fiber proportion and performance of concrete. Sim et al. [12] investigated the influence of basalt fiber on structural concrete and found that basalt fiber is a good substitute for strengthening concrete structures. In addition, Kim et al. [13] considered two type of concretes; normal concrete and high - fluidity concrete. Whereas, they found that the addition of 1% jute fiber by volume in th e normal strength concrete does not deliver significant increment, but in high-fluidity concrete it gives a substantial rise in compressive strength , around 55%, a s c o m p are d to one without fiber. The compressive strength of 0% jute fiber content for high-fluidity concrete gives 25 MPa and for 0.5% of jute fibe r content deliver about 42 MPa, which indicated that the presence of fibers could positively influence the concrete perform a nc e. Hence, it was generally observed that the flexural strength can be increased as the fibe r content increased in concrete. However, presence of fiber can resist tensile load and increase the flexural strength. 103 IIUM Engineering Journal, Vol. 21, No. 2, 2020 Wan Ibrahim et al. https://doi.org/10.31436/iiumej.v21i2.1285 3. MATERIALS AND METHODOLOGY 3.1 Materials Ordinary Portland cement (OPC) was used in this study. The coarse aggrega te s w e re collected from Muar, Johor, Malaysia. This study considered a 10 mm average o f c o ars e aggregate. After collection, coarse aggregates were dried under open sun for f e w d a y s to achieve saturated surface dry (SSD) conditions. However, the fine aggregates (sand) w e re transported from a river in Kahang, Johor, Malaysia. The fine aggregates were a ls o d rie d for a few days under open sunlight to achieve saturated surface dry (SSD) cond itions. Before mixing, the sand was sieved through a 5 mm sieve. 3.2 Palm Oil Biomass Clinker This study considered Palm Oil Biomass Clinker (POBC) as shown in Fig. 4, which was collected from a biomass steam plant located in Tanjung Langsat, man age d b y TPM Technopark Sdn Bhd. Initially, it was partially replaced by the fine aggregate (sand ). Th e optimum replacement percentages of sand with POBC was chosen as 10% based previo us studies [4]. Afterward, POBC were passed through a 5 mm sieve size. Furthermore, a random sample of POBC was investigated with a Scanning Electron Microscope (SEM) for an understanding of its microstructure, as shown in Fig. 5. It was observed that PO BC has micro voids that could affect the properties of concrete and create weak region s in th e form of free voids. The presence of voids is the significant cause of reduction in s tre n gth of concrete. These voids also provide a gap between particles and result in wea k e r b o nd s in the hardened concrete. Some organic compounds were noticed on the surface of the POBC. It can be concluded that POBC contain s voids and organic compounds tha t a f fec t its porosity and low value of specific gravity. Fig. 4: Palm oil biomass clinker. Fig. 5: SEM image of POBC. 3.3 Palm Oil Empty Fruit Fibers Palm oil empty fruit bunch (EFB) fibers, as shown in Fig. 6, were used in th is s tu d y . The length of the palm oil EFB fiber was fixed at the range of 30 mm to 50 mm with a diameter of around 0.05 mm. The aspect ratio of the palm oil EFB fibers was in the ra n ge of 60 to 100 for better strength development. 104 IIUM Engineering Journal, Vol. 21, No. 2, 2020 Wan Ibrahim et al. https://doi.org/10.31436/iiumej.v21i2.1285 Fig. 6: Palm oil empty fruit bunch fibers. 3.4 Experimental Procedure In this study, normal concrete mix design was prepared for 25 MPa at 28 days w ith a fixed water-to-cement ratio of 0.50. A total of four mixes were prepared; one was the reference mix with 10% POBC but without fibers and the other three c o nta in ed v a ryin g amounts of palm oil EFB fiber at 0.2, 0.4 and 0.6% by weight total batch mix. The quantity of fiber was calculated by multiplying the overall weight of ingredients of the concrete mix with the percentage of fiber content. The concrete mix details are provided in Table 1. Table 1: Mix design detail (kg/m3) for concrete containing POBC with palm oil EFB fiber Sample Notation Cement Sand CA POBC Water EFB Fibers 0% EFB 18.24 37.80 28.62 0.00 9.12 - 0.2% EFB 18.24 34.02 28.62 3.78 9.12 0.195 0.4% EFB 18.24 34.02 28.62 3.78 9.12 0.390 0.6% EFB 18.24 34.02 28.62 3.78 9.12 0.585 Overall, 48 specimens were prepared to explore the compressive and flexural strength of the concretes at 7 and 28 days, as mentioned in Table 2. Concrete cubes of 100 mm size were cast for the purpose of compressive strength. The prisms of 100 mm in cross -sectio n and 500 mm in length were cast for the evaluation of flexural strength. Furthermore, curing of concrete was observed under water immersion conditions. Table 2: The Specimen prepared for strength performances Palm Oil EFB fibers (%) 7 days 28 days Compressive Flexural Compressive Flexural 0 3 3 3 3 0.2 3 3 3 3 0.4 3 3 3 3 0.6 3 3 3 3 Sub Total 12 12 12 12 Tota l Sa mples 48 105 IIUM Engineering Journal, Vol. 21, No. 2, 2020 Wan Ibrahim et al. https://doi.org/10.31436/iiumej.v21i2.1285 4. RESULTS AND DISCUSSION 4.1 Particle Size Distribution Particle size distribution has been done through sieve analysis. Fig. 7 illustrates the cumulative percentages passing for sand and POBC at various sieve size s. H o w e v er, th e sand and POBC particle size distribution curve did not exceed the upper and lower lim it s . Both sand and POBC used in the experiment fulfil the particle size behaviour stated in BS 882: 1992, the required percentage by mass passing BS sieve for sand. In this study, aggregates used were air dried to obtain saturated dried surface. To achieve this condition, aggregates were dried at room temperature for 24 hours. Coarse aggregates of 10 mm size were used, and less than 5 mm were removed through sieving. The specific gravity for sand and POBC used in this study has the average specific gravity of 2.07 and 2.63, respectively. The specific gra v ity o f PO BC is 21% lower than the average specific gravity of sand. Fig. 7: Particle size distribution of sand and POBC. 4.2 Workability of Concrete Workability is an aspect of concrete, which indicates flow without mechanical shaking. The workability performance of concrete containing 10% POBC along with various proportions of palm oil EFB fiber are presented Fig. 8. It shows a reduction in workability due to the addition of fiber content. The slump value dropped from 2 0 m m to 18, 12, and 8 mm at fiber contents of 0.2, 0.4, and 0.6%, respectively. The results sh o w ed a substantial decrease in workability due to presence of fibe r. As the fiber content increased, workability was reduced. However, the presence of fiber absorbed mo re w a te r in the concrete mix [14] and resulted in the drop in workability. An adequate performan c e was noticed with 0.2% fiber. It was also previously noticed by Ahmad et al. [1 5 ] th a t th e addition of fibers cause the reduction in workability. However, the palm oil EFB f ib e r is an organic fiber that could reduce the quantity of free water in a concrete mixture and affect the mobility of concrete. 106 IIUM Engineering Journal, Vol. 21, No. 2, 2020 Wan Ibrahim et al. https://doi.org/10.31436/iiumej.v21i2.1285 Fig. 8: The slump value with various percentage of reinforced palm oil EFB fibe r. 4.3 Compressive Strength Compression strength test performances of concrete with 10% POBC as a fine aggregate replacement with the addition of 0.2%, 0.4%, and 0.6% of palm o il EFB f ib e r has been presented in Fig. 9. The experimental findings indicate that compressive strength was reduced as fiber quantity increased in the concrete. The control sample with o u t f ibe r shows the highest compressive strength of 27.23 MPa at 28 days. Compressive strength results with the addition of 0.2%, 0.4% and 0.6% palm oil EFB fibe r show a red u ctio n in strength of 12.6%, 17.7%, and 21.7% respectively. Comparatively, the strength performances with 0.2% fiber is considered to be satisfactory, due to the lower re d u ctio n in the strength [4,16,17]. This study clarifies that there is a continual decrease in compressive strength as palm oil EFB fibers increase in the concrete mix. It shows that concrete becomes more porous and delivers lower strength. This study also validated th a t in the presence of both materials, POBC and palm oil EFB fiber, concrete depletes its water content, since more water is absorbed by these two materials. As a result, redu c tion in water content could slow the hydration process of concrete and ultimately cause it to exhibit lower strength, even at 28 days. Fig. 9: Compressive strength of fiber reinforced concrete at different curing periods 4.4 Flexural Strength Experimental results of flexural strength of concrete incorporating 10% POBC as fine aggregate replacement along with the addition of 0.2%, 0.4% and 0.6% o f p a lm o il EFB 20 18 12 8 0 5 10 15 20 25 0% (C ontrol) 0.2% 0.4% 0.6% S lu m p ( m m ) Pe rce n tage of Pal m O il EFB Fi be r (%) 25.71 27.23 21.26 23.73 20.94 22.40 20.39 21.30 20 22 24 26 28 30 7 Days 28 Days C o m p r e s si v e S tr e n g th ( M P a ) C u ri n g Age (Days) 0% (C ontrol) 0.2% 0.4% 0.6% 107 IIUM Engineering Journal, Vol. 21, No. 2, 2020 Wan Ibrahim et al. https://doi.org/10.31436/iiumej.v21i2.1285 fiber has been demonstrated in Fig. 10. It was observed that flexural strength o f c o nc re te was better in the presence of fibers. It was noticed that flexural strength was increased from 2.18 MPa to 2.43 MPa with the addition of 0.2% fiber, which is almost 11. 47 % ris e in flexural strength at 28 days. However, 0.4% and 0.6% fiber content also delivers around 5.96% and 4.59% improvement in the flexural strength of concrete. Hence, it is worth noting here that the increase in palm oil EFB fiber content causes a reductio n in f le xu ral strength. It was previously acknowledged that the addition of supplementary materials along with fibers enhances the flexural strength of concrete [4,18,1 9, 2 0, 21 ]. Th is s tu d y also experimentally validated that 0.2% proportion of fiber enhances the concrete properties in terms of flexural strength, and it is hereby recommended a s a n a p p ro pria te proportion of fibers in a concrete mix. Fig. 10: Concrete flexural strength at curing periods of 7 and 28 days. 5. CONCLUSIONS This experimental study confirmed that POBC has a good potential to be utilized a s a fine aggregate replacement. Based on the performance of concrete containing 10% PO BC as fine aggregate with addition of palm oil EFB fibe r, the following conclusions can be made: • Concrete containing 10% POBC as a fine aggregate along with additio n o f p a lm oil EFB fiber delivers lower workability performances and around 10% reduc tio n in workability with the addition of 0.2% fiber in concrete. • Concrete compressive strength was also reduced with addition of 0.2%, 0.4% a n d 0.6% palm oil EFB fiber, which gives around 12.6%, 17.7%, and 21.7% reduction in compressive strength, respectively. However, 0.2% fiber content is declare d a s optimum, due to minimum reduction in the strength. • The flexural strength performances of concrete were found to be in c re as e d f ro m 2.18 MPa to 2.43 MPa with the addition of 0.2% fiber, which is almost an 11.47% rise in flexural strength at 28 days. Therefore, based on the experimental outcomes, the appropriate proportion of fiber is recommended to be 0.2%. 2.18 2.18 2.22 2.43 2.20 2.31 2.18 2.28 2 2.1 2.2 2.3 2.4 2.5 7 Days 28 Days F le x u r a l S tr e n g th ( M P a ) C u ri n g Age (Days) 0% (C ontrol) 0.2% 0.4% 0.6% 108 IIUM Engineering Journal, Vol. 21, No. 2, 2020 Wan Ibrahim et al. https://doi.org/10.31436/iiumej.v21i2.1285 ACKNOWLEDGEMENTS This study was supported by Universiti Tun Hussein Onn Malaysia (UTHM) and Ministry of Education Malaysia through Fundamental Research Grant Scheme Vot No. FRGS/1/2018/TK01/UTHM/02/3. REFERENCES [1] Kushairi A, Loh SK, Azman I, Hishamuddin E, Abdullah MO, Mohd Noor Izuddin ZB, Razmah G, Sundram S, Ahmad Parveez MK. (2018) Oil Palm Economic Performance in Malaysia and R&D Progress in 2017 – Review Article. Journal of oil palm research 30(2):163-195. DOI: https://doi.org/10.21894/jopr.2018.0030 [2] Kanadasan J, Razak HA. 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