improving the properties of lateritic soil ... study is to determine the effect of rice husk ash and...

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Proceedings of The Academic Conference of African Scholar Publications & Research International on Challenge and Prospects Vol. 8 No. 2. 10th December, 2015 – Bauchi State University, Gadau, University Assembly Hall, Mai Campus, Itsa-Gadau, Bauchi State. IMPROVING THE PROPERTIES OF LATERITIC SOIL STABILIZED WITH RICE HUSK (POWDERED AND ASH) FOR BRICKS 1 DAMMO. M.N*; 1 JOSEPH I.A; 1 DEBORAH. J.M; 1 G B. YUSUF; 2 AJI .B; AND 1 JIDDA .M ABSTRACT This research determined the effect of lateritic soil modified with rice husk powdered and ash with a view to obtaining a cheaper and effective replacement for the conventional soil stabilizers. Preliminary tests were performed on the sample, for identification and classification purposes. Compressive strength was investigated after 7, 14 and 28 days of curing. Each of the two stabilizers (rice husk powdered and ash) were added in varying proportions of 2%, 4%, 6% and 8% by weight of the lateritic soil for producing the bricks. Compressive strength test conducted revealed that the cement stabilized bricks for rice husk ash and powdered developed a rapid increase in strength from 0.76 to 3.38kN/m 2 and 0.76 to 3.76kN/m 2 respectively. Rice husk powdered and ash was therefore found as an effective stabilizer for lateritic soils. In all, the compressive strength increased with increasing proportion of the stabilizers INTRODUCTION Soil stabilization may be defined as any process aimed at improving the performance of a soil as a construction material. Bell (1993), referred to soil stabilization as the process of mixing additives with soil to improve its volume stability, strength, permeability and durability. The soil that is of concern in this study is laterite. Laterite is a red tropical soil that is rich in iron oxide and usually derived from wide variety of rock weathering under strongly oxidizing and leaching conditions. It forms in tropical and sub-tropical regions where the climate is humid (Raheem et al; 2010). Replacement of Portland cement is a promising application not only in the field of concrete but also in the field of soil improvement, and effect of calcium silicate hydrate is expected to be similar within soil grains. Research on this application of rice husk ash has been carried out more often recently and all of them share the same observation that in cooperation with lime, the mixture can help to considerably improve the strength, permeability, durability and volume stability of different types of soft soil. The main advantage of the lime-rice husk ash cement compared with the Portland cement is that it can save much energy. Detail calculation of comparison between the two systems by a simple Life cycle inventory analysis in the Appendix 1 shows that the electricity used by the system of lime and rice husk ash is only one fifteenth of the amount of the case of Portland cement.

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Page 1: IMPROVING THE PROPERTIES OF LATERITIC SOIL ... study is to determine the effect of rice husk ash and powdered stabilization with lateritic soil. Lateritic Soil and Stabilization: The

Proceedings of The Academic Conference of African Scholar Publications & Research International on Challenge and Prospects Vol. 8 No. 2. 10th December, 2015 – Bauchi State University, Gadau, University Assembly Hall, Mai Campus,

Itsa-Gadau, Bauchi State.

IMPROVING THE PROPERTIES OF LATERITIC SOIL STABILIZED WITH RICE HUSK (POWDERED AND ASH) FOR BRICKS

1DAMMO. M.N*; 1JOSEPH I.A; 1DEBORAH. J.M; 1G B. YUSUF; 2AJI .B; AND 1JIDDA .M

ABSTRACTThis research determined the effect of lateritic soil modified with rice husk powdered and ash with a view to obtaining a cheaper and effective replacement for the conventional soil stabilizers. Preliminary tests were performed on the sample, for identification and classification purposes. Compressive strength was investigated after 7, 14 and 28 days of curing. Each of the two stabilizers (rice husk powdered and ash) were added in varying proportions of 2%, 4%, 6% and 8% by weight of the lateritic soil for producing the bricks. Compressive strength test conducted revealed that the cement stabilized bricks for rice husk ash and powdered developed a rapid increase in strength from 0.76 to 3.38kN/m2 and 0.76 to 3.76kN/m2 respectively. Rice husk powdered and ash was therefore found as an effective stabilizer for lateritic soils. In all, the compressive strength increased with increasing proportion of the stabilizers

INTRODUCTION Soil stabilization may be defined as any process aimed at improving the performance of a soil as a construction material. Bell (1993), referred to soil stabilization as the process of mixing additives with soil to improve its volume stability, strength, permeability and durability. The soil that is of concern in this study is laterite. Laterite is a red tropical soil that is rich in iron oxide and usually derived from wide variety of rock weathering under strongly oxidizing and leaching conditions. It forms in tropical and sub-tropical regions where the climate is humid (Raheem et al; 2010). Replacement of Portland cement is a promising application not only in the field of concrete but also in the field of soil improvement, and effect of calcium silicate hydrate is expected to be similar within soil grains. Research on this application of rice husk ash has been carried out more often recently and all of them share the same observation that in cooperation with lime, the mixture can help to considerably improve the strength, permeability, durability and volume stability of different types of soft soil. The main advantage of the lime-rice husk ash cement compared with the Portland cement is that it can save much energy. Detail calculation of comparison between the two systems by a simple Life cycle inventory analysis in the Appendix 1 shows that the electricity used by the system of lime and rice husk ash is only one fifteenth of the amount of the case of Portland cement.

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The common sense for rice husk ash producing is the more active ash the more efficient reaction, so almost all the experiments for soil improvement were implemented with the ash which is supposed to be active by burning at an appropriate temperature and duration. However, exothermic property of the burning rice husk makes the inner temperature of the burning mass uncontrollable. Consequently the quality of the rice husk ash can be largely various even the burning condition is set up at the optimum, accordingly the overall positive effect of the additives might come not only from the good quality of the ash. There was also research about soil improvement effect with uncontrolled burnt ash and it also showed a good result(Vinh Pham, 2012). Rice husk ash (RHA) is a poor nutrition material and it is rarely used for agricultural purposes such as animal food or fertilizer. The feature property of the rice husk is that its combustion heat is approximately 13.4 MJ/kg, which is a high average calorific value [16]. The inorganic component lying in the collected ash after burning is dominated by silica. The ash is about 20% of weight of the rice husk, and silica amount can reach to 96% of the ash by appropriate burning condition. Consequently, the main perspectives of utilizing rice husk are for energy purpose and silica resource.In terms of energy, comparison to coal whose combustion heat is about 30 MJ/kg [17] shows that a ton of rice husk is equivalent to 0.4 ton of coal. Besides, being plants means that this source of energy is CO2 neutral as CO2 released from pyro-processing is equal to the consumed amount during its life [18]. The needs for adequate provisions of building facilities are enormously increasing with increase in population and also the maintenance of the existing one. Engineers are faced with the problems of providing very suitable materials for the Building construction. Owning to this fact, continuous researches have been carried and still being carried out by individual, firms and institutions on ways to improve the engineering properties of soils. The most available soils do not have adequate engineering properties to really bear the load. So improvisations have to be made to make these soils better. These lead to the concept called soil stabilization which is any treatment (including, technically, compaction) applied to a soil to improve its strength and reduce its vulnerability to water, if the treated soil is able to withstand the stresses imposed on it by all weather conditions without excessive deformation, then it is generally regarded as stable. Several buildings and pavement in Nigeria roads are failing due to lack of use of soil with adequate Engineering strength. So the need for improvement of the engineering properties of soil has been a paramount concern to the building and transportation engineers. The ability to blend the naturally abundant lateritic soil with some chemical reagent to give it better engineering properties in both strength and water proofing has been of paramount importance. In bid to improve the engineering properties of soil to make it suitable for building construction, several researches on soils Stabilization have been carried out. Rice husk is a major by product in the manufacturing of rice in the rice industries. Proper disposal of waste product has been a global concern. In order to make rice husk a useful material, several researches have been conducted. Some of the researches show that rice husk powdered and ash contains a high amount of silicon oxide making it highly pozzolanic. The aim of

Page 3: IMPROVING THE PROPERTIES OF LATERITIC SOIL ... study is to determine the effect of rice husk ash and powdered stabilization with lateritic soil. Lateritic Soil and Stabilization: The

this study is to determine the effect of rice husk ash and powdered stabilization with lateritic soil.

Lateritic Soil and Stabilization:The word Laterite describes no material with reasonable constant properties. To those in the temperate countries, it could be described as a red friable clay surface. To those in the hilly tropical countries, it could be described as a very hard homogenous vescular massive clinker – like materials with a framework of red hydrated ferric oxides of vescular infill of soft aluminium oxides of yellowish colour and in less hilly country, it could exist as a very hard, or soft coarse angular red. Lateritic soils as a group rather than well-defined materials are most commonly found in a leached soils of humid tropics. Laterite is a surface formation in hot and wet tropical areas which is enriched in iron and aluminium and develops by intensive and long lasting weathering of the underlying parent rock (Wikipedia, 2007). In order to fully appreciate the usefulness of lateritic soil, its problems (in both field and laboratory) would have to be identified and useful solutions applied. The mechanical instability, which may manifest in form of remoulding and manipulation, results in the breakdown of cementation and structure. The engineering properties affected by this mechanical instability include particle size, Atterberg’s limits, and moisture-density distribution. Thermal instability is shown through sensitivity to drying to be described as potential self-stabilization. The affected engineering parameters are Atterberg’s limits, particle size distribution. The effects of these problems therefore affect the strength of the material. Soil stabilization is any treatment applied to a soil to improve its strength and reduce vulnerability to water, if the treated soil is able to withstand the stresses imposed on it by traffic under all weather conditions without deformation, then it is generally regarded as stable.

RICE HUSH ASH% KN/m2 7 14 21 28

0 0.76 0.82 1.3 2.16 3.122 0.89 1.03 1.4 2.52 3.354 1.00 1.16 1.5 2.65 3.576 1.31 1.74 1.95 3.26 4.088 1.28 1.54 1.6 2.94 3.76

RICE HUSK % KN/m2 7 14 21 28

0 0.76 0.82 1.3 2.16 3.122 0.67 0.84 1.27 2.12 3.184 0.80 0.89 1.30 2.35 3.296 1.23 1.36 1.65 2.70 3.678 0.98 1.14 1.37 2.44 3.38

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Materials and Preparation The lateritic soil sample used for the study was collected from a construction site in Bukuru Plateau State, Nigeria. Materials were mixed thoroughly to achieve a homogeneous mixture using shovel and masonry trowel. After thorough mixing of the constituent materials, the mould box of the CINVA-Ram machine was greased with oil to allow easy removal of bricks. Mixed samples were fed into the mould box and covered. It was then compressed by a hand operated toggle level and piston system, which exerted a minimum compacting pressure of about 2 MN/m2. After compression, the cover was removed while the mould box was jacked upward to remove the brick. Fig. 2 shows a produced brick. A total of ninety bricks were moulded, comprising of nine bricks produced for each proportion of the stabilisers used and also nine for the unstabilised bricks.

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DISCUSSIONThe Atterberg limits are significantly altered with lime and rice husk ash combinations. Muntohar (2000) and Mtallib, M.O. A (2011) found out that the liquid limit reduces and plastic limit increases with increasing lime and rice husk ash combinations. This is attributed to the fact that the rice husk ash pozzolanic reaction with the lime form compounds possessing cementitious properties with soil particles. Their results also show decrease in the plasticity index at all lime and rice husk ash contents which makes the stabilized soils better for use as construction materials. Research on the potential of using rice husk ash, reveals that some of its physical properties are responsible for the role that rice husk ash plays in improving the material properties and durability of its composite. Some of these physical properties are larger specific surface area, fine particle size. (Safiuddin, 1990, cited in Obam and Iorliam, 2011) Table 2 shows some physical properties of RHA as published by Narayan ( Obam and Iorliam, 2011)

[1] Conclusion [2] According to experimental results, the unstabilized brick sample (sample F) exhibits

compressive strength value of 0.9 N/mm2. But when admixed with lime and RHA combinations at varying percentages, considerable improvement can be seen in the compressive strength values. Specifically, the compressive strength was 4 N/mm2 at 12.5% Lime and 12.5% RHA combination. In general 10 % lime and 2.5% of RHA combination (compressive strength of 3.9 N/mm2) can be taken as the economical dosage to stabilize the soil bricks.

[3] According to the BS 3921 the compressive strength of a brick should not be less than 5 N/mm2. However in practice, typical compressive strengths for stabilized soil bricks are less than 4 N/mm2. Local bricks presently in use have compressive strength within the range of 0.5 N/mm2 to 1.75N/mm2 which is much below the standards (Bogahawatta V.T.L). Where the buildings loads are small, in the case of single storey constructions a compressive strength of 1- 4 N/mm2 is sufficient. Many building authorities around the world recommend values within this range. These stabilized bricks are also suitable to be used for non load bearing partition walls where high compressive strength is not essential.

[4] Density of stabilized soil bricks are not very high (< 1900 kg/m3) and within the range of normal fired clay bricks density (1300 – 2200 kg/m3). This may be considered as an advantage, when the bricks have to be transported over long distances.

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[5] In comparison with water absorption of different types of clay bricks available in Sri Lanka, lime- rice husk ash stabilized soil bricks exhibit low water absorption value. ( < 20 % )

Stabilized blocks can be produced on site itself or nearby area using excavated soil for construction. Thus, it will save the transportation cost and time. Since they can be manufactured by semi skilled labour, local economy will flourish. The use of natural, locally-available waste materials such as rice husk ash directs to sustainable construction. Since energy consumption and air pollution is much less than fired bricks, stabilized blocks can be labelled more eco friendly. If demand of RHA increases, rice mill owners can adopt technologically advanced furnaces to incinerate rice husks at controlled conditions. It will also create a positive impact on the air quality.

REFERENCESen-Hwei Hsu and B.S. Luh, Rice Hulls, in Rice: Production and Utilization, B.S. Luh, Editor 1979,Avi Publishing Company: Connecticut. p. 736-763.Catelin, M., 2010 Survey of Energy Resources - Coal, 2010, World Energy Council.REFUEL. Intelligent Energy Europe. 16 Feb 2012]; Available from:[6] http://www.refuel.eu/biofuels/.Vinh Pham, (2012). Utilization of rice husk ash in geotechnoloy: applicability and effect of the burning condition. Thesis

A.A. Raheem.; O.A. Bello.; and O.A. Makinde (2010). A Comparative Study of Cement and Lime Stabilized Lateritic Interlocking Blocks. The Pacific Journal of Science and Technology Vol11.(2). Pp 27-37

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Rice husk

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Rice husk ash

REFERENCES(1) British Standards Institute, 1981, BS 3921 (1981), Specification for clay bricks (2) British Standards Institute, 1981, BS 1377 (1990), Specification for soil tests

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(3) Dolage D.A.R., Mylvaganam K, Mayoorathan P and Inparatnam S, April 2011, “Use of Rice Husk Ash Blended Cement to Produce Cement Sand Blocks”, ENGINEER, Vol.45, No.02, PP (11-19). (4) Food and Agriculture Organization of United Nations, Trade and Market Division, April 2010, FAO Rice Market Monitor, Volume 13, Also available at:http://www.fao.org/economic/est/publications/rice-publications/rice-market-monitor-rmm/en/ (5) Mtallib, M.O. A, 2011, “The Improvement of the Index Properties and Compaction Characteristics of Lime Stabilized Tropical Lateritic Clays with Rice Husk Ash (RHA) Admixtures”, The Electronic journal of Geotechnical Engineering, Volume 16 (6) Musa Alhassan and Alhaji Mohammed Mustapha, 2007, “Effect of Rice Husk Ash on Cement Stabilized Laterite”, Leonardo Electronic journal of Practices and Technologies, Issue11, PP (47-58). (7) Musa Alhassan, Apr. 2008, Potentials of Rice Husk Ash for Soil Stabilization, AU J.T. 11(4),PP: 246-250 (8) Musa Alhassan, Oct. 2008, Permeability of Lateritic Soil Treated with Lime and Rice Husk Ash, AU J.T. 12(2),PP: 115-120 (9) Nick Zemke Emmet Woods, 2009, “Rice Husk Ash”, California Polytechnic State University, Available at: http:// cvbt-web.org (10)Ogah Sylvester Obam and Amos. Y. Iorliam, 2011, “Engineering Properties of clay-Rice Husk Ash Composites”, Journal of Engineering and Applied sciences, Volume 3 (11)Oyekan, G.L, Kamiyo,O.M, March 2011, “A study on the engineering properties of sandcrete blocks produced with rice husk ash blended cement”, Journal of Engineering and Technology Research, Volume 3 (3),PP (88-98). (12)Ravande Kishore, Bhikshma V. and Jeevana P, 2011, Study on Strength Characteristics of High Strength Rice Husk Ash Concrete, The Twelfth East Asia-Pacific Conference on Structural Engineering and Construction, Available at www .sciencedirect.com (13)Suraya Abdul Rashid, Alireza Naji Givi and Farah Nora A.Aziz, 2010, “Contribution of Rice husk ash to the properties of Mortar and concrete”, Journal of American Science, Volume 6 (3), PP : 157-165 (14) Bogahawatta V.T.L, Building materials in Sri Lanka