Effects of kaolin calcined at different temperatures on the properties of river sand and quarry dust concrete
Date
2024-04
Authors
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Journal ISSN
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Publisher
Federal University of Technology, Owerri
Abstract
The study explored the mechanical and durability properties of concrete blended with kaolin from Umuariaga, Ikwuano Local Government Area, Abia State, Nigeria. The kaolin was calcined at 6500C, 7500C, and 8500C accordingly to obtain metakaolin (MK). Two sets of binary concrete were investigated. The first set was composed of Portland cement, metakaolin, river sand (RS) and crushed granite. While, the second sample was made of a similar composition except that quarry dust (QD) was used in place of river sand. MK was utilized to replace Portland cement at percentages ranging from 0% to 50% at 5% intervals. Mix ratio of 1: 1.68: 2.32 (i.e. cement: river sand: crushed granite) and 1:1.42:2.04 (i.e. cement: quarry dust: crushed granite) at 0.4 water-cement ratio targeting 30 MPa compressive strength value were experimented. The compressive strength, young modulus of elasticity and water absorption property of the various concrete cube samples of size 150×150×150 mm3 were tested after curing by immersing in water for 7 and 28 days. The multiple regression analysis (MRA) of the experimental data was conducted using historical design (HD) of the response surface methodology (RSM). This was implemented using the Design expert software version 13. Generally, the results show that the effect of the different calcination temperatures for producing the metakaolin did affect the slump and strength properties of the concrete. However, as the percentage of metakaolin increased, the slump values lessened for both RS and QD concrete. At 0%MK for all three temperatures, the maximum slumps for RS and QD concrete were found to be 112 mm and 98 mm, respectively. Minimum values were noted at 50% inclusion of MK. It was found that, for both types of concrete, the compressive strength values at 7500C were slightly higher than the other two temperatures. After 28 days, the binary concrete containing river sand exhibited the highest compressive strength at 15%MK for 6500C, 20%MK for 7500C, and 20%MK for 8500C, with corresponding values of 38.92 N/mm2, 42.05 N/mm2, and 40.98 N/mm2. While the quarry dust concrete had 36.48 N/mm2, 38.02 N/mm2, and 36.30 N/mm2 for 6500C, 7500C, and 8500C respectively, all at 20%MK. The Young modulus for the river sand had 33.55 GPa at 15%MK, 34.88 GPa at 20%MK, 34.30 GPa at 20%MK while the young modulus for quarry dust had 32.45GPa at 20%MK, 33.16 GPa at 20%MK, 32.64GPa at 20%MK for 6500C, 7500C, and 8500C respectively. The Water absorption for river sand had 1.22% at 20%MK, 1.10% at 20%MK, 1.22% at 20%MK while the water absorption for quarry dust had 1.46% at 20%MK, 1.33% at 20%MK, 1.45% at 20%MK for 6500C, 7500C, and 8500C respectively. The multiple regression analysis gave a 2-factor interaction (2FI) model for the best binary concrete achieved at 750 0C with R-squared values of 0.9182, 0.9451, and 0.9566 for compressive strength, young modulus and water absorption respectively with river sand. While with the quarry dust, the R-squared values of 0.9618, 0.9756, 0.9953 for compressive strength, young modulus and water absorption respectively was achieved. The investigation showed that metakaolin gotten from Umuariaga, Abia State in Nigeria improved the mechanical and durability properties of the tested concrete from 5%MK -20%MK replacement level.
Description
This thesis is for the award of Master of Engineering (M.ENG) in Civil Engineering (Structures)
Keywords
Metakaolin, binary concrete, compressive strength, young modulus, water absorption, response surface methodology, Department of Civil Engineering
Citation
Ibe, K. C. (2024). Effects of kaolin calcined at different temperatures on the properties of river sand and quarry dust concrete (Unpublished Master's Thesis). Federal University of Technology, Owerri, Nigeria