The Performance of Concrete with Rice Husk Ash, Sea ... - ScienceDirect

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ScienceDirect Procedia Engineering 95 (2014) 473 – 478

2nd International Conference on Sustainable Civil Engineering Structures and Construction Materials 2014 (SCESCM 2014)

The performance of concrete with rice husk ash, sea shell ash and bamboo fibre addition Ade Sri Wahyuni*, Fepy Supriani, Elhusna, Agustin Gunawan Department of Civil Engineering, Bengkulu University, Jalan WR Supratman, Kandang Limun, Bengkulu 38371A, Indonesia

Abstract Concrete has good compressive but low in tensile strength. The addition of natural fibre into fresh concrete can increase the ductility of the concrete matrix. This research aims to investigate the tensile strength of concrete with 0.50% addition of bamboo fibre based on cement weight. To increase the strength of concrete, the mixture of rice husk ash (RHA) and sea shell ash (SSA) was used as partial replacement of fine aggregate. The replacement is devided into four different percentages namely 10%, 20%, 30% and 40% based on the weight of fine aggregate. The experimental work consisted of casting 13 different types of concrete to be compared in term of splitting tensile strength at the age of 28 and 90 days. In general the tensile strength of bamboo fibre reinforced concrete is comparable to that of Normal Concrete. © Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license ©2014 2014The The Authors. Published by Elsevier Ltd. (http://creativecommons.org/licenses/by-nc-nd/3.0/). Peer-review under responsibility of organizing committee of the 2nd International Conference on Sustainable Civil Engineering Peer-review under responsibility of organizing committee of the 2nd International Conference on Sustainable Civil Engineering Structures and Construction Materials 2014. Structures and Construction Materials 2014

Keywords: bamboo fibre, waste materials, lightweight concrete

* Corresponding author. Telp.: +62-8161-7306-079 E-mail address: [email protected]

1877-7058 © 2014 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license

(http://creativecommons.org/licenses/by-nc-nd/3.0/). Peer-review under responsibility of organizing committee of the 2nd International Conference on Sustainable Civil Engineering Structures and Construction Materials 2014

doi:10.1016/j.proeng.2014.12.207

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Ade Sri Wahyuni et al. / Procedia Engineering 95 (2014) 473 – 478

1. Introduction The concept of environmentally friendly technology has inspired the researchers to do more in protecting the environment. Utilization of waste materials as alternative building materials has become the popular way to overcome the environmental problem in most developing countries [2,5,7]. Waste materials such as Rice Husk and Sea Shell have great potential to be used as building materials. The combination of high silica content from Rice Husk Ash, and CaO from the Sea Shell Ash has pozzolanic behaviour which influence the concrete strength. Furthermore, it is encouraged to use the renewable resources as building materials for continuing availability of building materials. The focus on this research is utilizing the bamboo fibre in concrete. Bamboo plant grows very well in Bengkulu province. This concrete also utilize the waste materials which is available abundant in Bengkulu namely the Rice Husk Ash and the Sea Shell Ash. The usage of material that is available in the area will save the cost of the construction. 2. Literature review Concrete, as the most used material on earth, is known for its high compressive strength and low tensile strength. Adding fibre into reinforced concrete becomes popular to increase the tensile strength of concrete. The research about improving the concrete performance by using waste material and renewable resources is very popular as part of “green technology program”. Rice Husk Ash (RHA) is gaining its popularity to be used in concrete due to the silica content. Many researchers try to utilize the RHA as partial replacement of cement. Ramezanianpour et al [9] reported that cement replacement by RHA for up to 15% could enhance the durability of RHA concrete and reduced the chloride diffusion. The duration and temperature of furnace are important parameters that influence the reactivity of RHA pozzolans. Research by Kartini [6] shows the optimum replacement of OPC with RHA taken at 28 days strength for Grade 30 and 40 was 30% and 20 % for grade 50. This replacement also reduced the water permeability of the concrete. The result of research conducted by Habeeb and Mahmud [4], said that 10 % replacement of RHA gave excellent improvement in strength and still worked for up to 20% cement replacement. The fineness of the RHA could also influence the strength of the concrete. Previous research shows different percentages of RHA which is acceptable in concrete as partial cement replacement. The different source and treatment of RHA might contribute to the variation of the results. The following literatures are about the fiber addition into concrete. Torgal and Jalali [14] said that promoting the use of concrete reinforced with vegetable fibres could be a way to improve concrete durability and also sustainable construction. Adding the short-fibre reinforcement in low volumes (less than 2-3%) can increase the fracture toughness of concrete that will help to control the width of crack that form due to the volume changes in concrete [10]. When concrete cracks, fibres help to bridge a crack and transfer load across the crack. As such, fibre reinforcement will limit the extent of restrained shrinkage cracking by limiting the width of the crack that forms in concrete elements [12, 13] Bamboo is chosen because of good behavior such as the Modulus of Elasticity which is very similar to that of concrete, susceptible to volume changes in water and Increases ultimate tensile strength [3, 11]. Ni [8] suggested that the fibre strength was particularly important to composite toughness but not as important to the strength. Examination of SEM micrograph, of the composite fracture surfaces, showed that the samples containing the weaker fibre had produced the expected higher population of broken fibres than samples containing the stronger fibres The problems with product from unprocessed natural fibres such as coconut coir, sisal, sugarcane bagasse, bamboo, jute, wood and vegetable fibres have been reported with the long term durability of some of the products. The properties of concrete made using unprocessed natural fibres depend on a number of factors including the type and length of fibre as well as the volume fraction. To show some improvement in mechanical properties, the minimum fibre content is of the order of 3% by volume [1].


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3. Experimental investigation The combination of three different mixture of RHA and SSA i.e : 65:35, 50:50, 35:65 will replace 10% , 20%, 30% and 40% of fine aggregate by weight. The bamboo fibre added is 0.5% of cement weight. It is expected that there will be no delay in increasing strength of the concrete as the same amount of cement used for all type of concrete. The cylinder mould measuring 150 mm in diameter and 300 mm in height were prepared for indirect tensile strength test. The specimen were cast, demoulded after 24 hours and cured in the curing tank until the day of testing. 3.1. Material used The Rice Husk Ash used in this research is originated from Sukaraja, Bengkulu, Sea Shell from Pulau Baai Bengkulu. Bamboo Betung which is already four years old is used as the fibre with dimension of 2 cm long. Fig.1 shows the Rice Husk Ash and the Sea Shell Ash, while Bamboo Fibre used in the concrete mixture can be seen in Fig. 2.

Fig. 1. Rice husk ash, sea shell ash

Fig. 2. Bamboo fibre

3.2. Aggregate The fine aggregate was obtained from Curup, Bengkulu, and the coarse aggregate with nominal size of 10 mm and 20 mm was from North Bengkulu. The physical properties of fine and coarse aggregate is tabulated in Table 1. Table 1. Physical properties of aggregate Properties

Result Fine agg

Coarse agg

Fineness Modulus (FM)

1.730

6.810

Specific Gravity

2.650

2.710

Bulk Density

1.427

1.391

3.3. Mix design Thirteen mixture proportions were made. Normal Concrete was used as the control mix. The water binder ratio was kept at 0.45. The slump value was 6-10 cm. The mix proportions for concrete and the RHA-SSA are given in Table 2 and Table 3 respectively.

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Table 2. Concrete mix design proportion No

Materials

Amount kg/m3

1

Cement

500.0

2

Fine Aggregate

560.6

3

Coarse Aggregate

934.4

4

Bamboo fibre

2.5

Table 3. The mixture proportion of RHA and SSA Type

% fine agg replacement

RHA:SSA

V1

10%

65:35

V2

10%

50:50

V3

10%

35:65

Fine Aggregate is replaced by 10% of the mixture of RHA and SSA with three different proportion by weight as stated in Table 3. The concrete variation V4-V12 is following the same pattern with increasing percentage of fine aggregate replacement i.e 20%, 30% and 40% respectively. 4. Result and discussion The test of tensile strenght of concrete was conducted in accordance with SNI 03-2491-2002 in concrete laboratory, Bengkulu University. The tensile strength of normal concrete was compared to 12 other types of concrete The test involved centering the sample in the testing machine. The force applied was at the constant rate until it reached the maximum force. Fig. 3a shows the splitting test set up with the fail cylinder sample. Fig. 3b. shows the inside of the concrete with scattered bamboo fibre. It is important to make sure that the bamboo fibre distributed evenly inside the concrete, so it does not create the weak spot that decrease the strength of the concrete.

Fig.3a. Splitting test set up

Fig.3b. Bamboo fibre inside the concrete

Fig. 4. shows the result of tensile strength test of Normal Concrete and 12 variation of concrete at the age of 28 and 90 days. In general, the splitting tensile of normal concrete is comparable to bamboo fibre reinforced concrete. It is clear from the graph that the tensile strength of V2, V4, V8 and V9 is higher than that of normal concrete by 26% at the age of 90 days.

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Ade Sri Wahyuni et al / Procedia Engineering 00 (2014) 000–000

3.9

Tensile strength (MPa)

3.8 3.4

3.6 3.4

3.9

3.9

3.3

3.9

3.8 3.7

3.5 3.3

3.9 3.6

3.5 3.2

3.3

5

3.6

3.5

3.2

3.2 2.9

3.2

3

2.7

NC

V1

V2

V3

V4

V5

V6

V7

V8

V9

V10 V11 V12

Type of concrete 28 days

90 days

Fig.4. The splitting tensile strength test results

Althouth most sample show the increasing number of Tensile strength at the later age , however the tensile strength of V3, V5, V6 and V7 decreased at the age of 90 days up to 30% . Further research is needed to verify this anomaly result. However it is too early to make any conclusion right now, as the test at later age will give the better picture of performance of the concrete with additive and bamboo fibre. 5. Conclusions In general the tensile strength of bamboo fibre reinforced concrete is comparable to that of Normal Concrete. Despite the strange result of a few sample which decrease at the later age, the bigger picture shows the addition of rice husk ash, sea shell ash and bamboo fibre, increase the tensile strength of concrete. It is too early to make the conclusion about the influence of Rice Husk Ash and Sea-Shell Ash in bamboo fibre reinforced concrete only with data at day 28 and 90 days. It is important to provide the data of compressive strength and tensile strength at later ages so, the better picture of the influence of the additives and fibre to concrete can be observed. Acknowledgements The authors would like to acknowledge the financial support through the Fundamental Research Grant from Directorate General of Higher Education Indonesia. References [1] Cement and Concrete Institute, Fibre Reinforced Concrete, Published by the Cement and Concrete Institute, Midrand. 2010. [2] P.Chindaprasirt, C. Jaturapitakkul, U. Rattanasak, Influence of Fineness of Rice Husk Ash and Additives on the Properties of Lightweight Aggregate, Fuel. 88 (2008) 158-162. [3] K. Ghavami, Bamboo as Reinforcement in Structural Concrete Elements, Cement and Concrete Composites. 27 (2005) 637-649.

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[4] G.A. Habeeb., H.B Mahmud, Study on Properties of Rice Husk Ash and Its Use as Cement Replacement Material, Material Research, 13(2) (2010) 185-190. [5] Z. Ismail., A. Enas, Use of Waste Plastic in Concrete Mixture as Aggregate Replacement, Waste management. 28 (2008) 2041-2047. [6] K. Kartini, Rice Husk Ash-Pozzolanic Material for Sustainability, International Journal of Applied Science and Technology. 1 (6) (2011) 169-178. [7] A.M Neville, Properties of Concrete, 4th edition, Pearson Education Limited, Essex, England. 1995. [8] Y. Ni, Natural Fibre Reinforced Cement Composites, Doctoral Thesis, Departmentof Mechanical Engineering, Victoria University of Technology, Australia. 1995. [9] A.A. Ramezanianpour, M. Mahdikhani, Gh. Ahmadibeni, The Effect of Rice Husk Ash on Mechanical Properties and Durability of Sustainable Concretes, International Journal of Civil Engineering. 7 ( 2) (2009) 83-91. [10] K Raoufi., J. Weiss,The Role of Fibre Reinforcement in Mitigating Shrinkage Cracks in Concrete, in Fibrous and Composite Materials for Civil Engineering Applications, Edited by R. Fangueiro, Woodhead Publishing Limited. 2011 [11] C.S. Rodrigues, K. Ghavami, P. Stroeven, Porosity and Water Permeability of Rice Husk Ash- Blended Cement Composites Reinforced with Bamboo Pulp, J. Material Science..41 (21) (2006) 6925-6937. [12] H.R. Shah, S.E. Swartz , C. Ouyang, Fracture Mechanics of Concrete, John Wiley & Son Inc, Chichester, England. 1995. [13] H.R .Shah, J. Weiss, Quantifying Shrinkage Cracking in Fibre Reinforced Concrete Using the Ring Test. Materials and Structures, 39 (9) (2006) 887-899. [14] F.P. Torgal., S.Jalali, Natural Fibre Reinforced Concrete, in Fibrous and Composite Materials for Civil Engineering Applications, Edited by R. Fangueiro, Woodhead Publishing Limited. 2011.