International Journal of Civil and Structural Engineering Research ISSN 2348-7607 (Online) Vol. 7, Issue 1, pp: (8-15), Month: April 2019 - September 2019, Available at: www.researchpublish.com
EXPLORING THE SUITABILITY OF NIGERIAN-BASED RICE HUSK ASH FOR HIGH STRENGTH CONCRETE PRODUCTION FOR USE IN CONSTRUCTION 1
Anthony O. Bucknor, 2Fisayo M. Animashaun, 3Festus A. Olutoge, 4 Oluwaseun A. Adetayo, 1
Department of Civil Engineering, University of Ibadan Department of Industrial and Production, University of Ibadan 3 Department of Civil Engineering, University of Ibadan 4 Department of Civil Engineering, Federal University of Technology Akure 2
Abstract: This study investigates properties of Nigerian-based RHA as a partial replacement for cement in HSC for sustainable and economic construction. Rice husks were obtained from Ire Ekiti, calcined to ash in a furnace under the range of 600 - 800℃, sieved and milled to improve the surface area and composition test was done. Two samples of RHA (milled and unmilled) were prepared and RHA-Cement blends using 0%,10%,20%,30%,40% and 50% by weight of cement. 72 cubes were prepared with an expected compressive strength of 60 MPa with each percentage replacement respectively having 12 cubes each for 7, 14, 21 and 28-days compressive strength to obtain the optimum percentage replacement. In the RHA produced, combined proportion of ( ), ( ), and ( ) gives 91.48% with loss of Ignition (LOI) of 3.79%, thus, satisfying ASTM 70% minimum requirement for the combined proportion of these oxides and 6% maximum Loss of Ignition. From the compressive strength test, the unmilled RHA -Cement blends performed poorly with respect to the control mix while the milled RHA -Cement shows an increase in strength and peaked at 10% with an average 28 days compressive strength of 63.70 MPa while 20% RHA gives 59.85 MPa. The close result of the average compressive strength of the 20% RHA to the target strength of 60 MPa, 10% and 20% RHA mixes were chosen as the likely optimum RHA replacement. With respect to these findings, Nigerian-based RHA shows promises for use in construction activities. Keywords: rice husk ash, sustainable, Nigerian, High strength concrete, construction.
I. INTRODUCTION The construction industry is one of two largest producers of carbon dioxide (CO 2), creating up to 5% of worldwide manmade emissions of this gas, of which 50% is from the chemical process and 40% from burning fuel [15], [6]. The CO2 emission from the concrete production is directly proportional to the cement content used in the concrete mix; 900 kg of CO2 is emitted from the production of every ton of cement, accounting for 88% of the emissions associated with the average concrete mix [9], [12]. Cement manufacture contributes greenhouse gases both directly through the production of carbon dioxide when calcium carbonate is thermally decomposed, producing lime and carbon dioxide, [5], [6] and also through the use of energy, particularly from the combustion of fossil fuels. The world’s annual consumption of Portland cement (1880 – 1996), rose from 2 million tons to 1.3 billion tons. The major environmental impact associated with the production
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