Effects of source location on the pozolannic properties of Rice Husk Ash (Rha) and strength properties of concrete

Godwin Adie Akeke *

Department of Civil Engineering, University of Cross River, Calabar.
 
Research Article
GSC Advanced Engineering and Technology, 2021, 02(01), 011–020.
Article DOI: 10.30574/gscaet.2021.2.1.0042
Publication history: 
Received on 25 October 2021; revised on 28 November 2021; accepted on 30 November 2021
 
Abstract: 
This paper presents the effects of variability in the chemical and elemental composition of Rice Husk Ash (RHA) sourced from four (4) different locations on Tensile Properties of Concrete. RHA is an agricultural waste gotten from rice mills after removal of rice paddy for food and burnt in open air or under controlled processes. RHA is found to be pozzolanic and can be used to partially replace cement to enhance the strength and quality of concrete. The different sources where RHA was gotten are; Ogoja, Abakaliki, Adani and Adikpo in Nigeria. It is discovered that the pozolanic properties of RHA varies based on their source location. Samples from Ogoja where found to have the highest pozzolanic properties followed by Abakaliki, Adani, and Adikpo, their silica content was found to be 84.55, 76.3, 70.12, 70.11, respectively. RHA was used to replace cement in concrete at 5, 10,15,20,25 and 30%. The compressive strength was determined and the values are as follows; And the compressive strength values at 28 days was found to be in the range of 37-42N/mm2 at 5%RHA, 35-39.5N/mm2 at 10%RHA, 30-34.5N/mm2 at 15%RHA, 27-29N/mm2 at 20%RHA, 22-25.6N/mm2 at 25% RHA and 21-24N/mm2 at 30% RHA compared to the controlled sample with a strength value of 42.64N/mm2. Cylindrical columns concrete of size 100mm diameter by 200mm long were moulded and stored in water for 28 days before testing for tensile splitting strength. The values determined from the split tensile test are as follows; 2.1-3.1N/mm2 at 5%RHA, 2.1-2.5N/mm2 at 10% RHA, 1.8-2.10 N/mm2 at 15% RHA, 1.2-1.7 N/mm2 at 20%RHA, 1.1-1.3 N/mm2 at 25% RHA and 0.62-0.9 N/mm2 at 30% RHA while the results of the controlled sample is 3.1 N/mm2.From the results above it can be deduced that source location influences the chemical properties of RHA strength characteristics of the Concrete with RHA as partial replacement.
 
Keywords: 
Rice Husk Ash (RHA); Pozolannic, strength; Concrete
 
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