Strength Characterization of Clay Deposits at College of Engineering, FUNAAB Abeokuta and Environs

Abstract

Most clay deposits in Abeokuta, Southwest, Nigeria, do not have comprehensive data on their general properties, making it difficult to utilize them in any engineering application. In order to establish whether the clay deposits at the college of engineering (COLENG), FUNAAB, Abeokuta and environs were suitable for use in ovens or furnaces, some of their physico-mechanical and thermal properties were examined. Clay deposits from the location were collected, pre-calcined to 120^oC and mixed with up to 20 wt% Portland cement, as binders. The samples were used to produce several bricks following recommendations from standard codes. Important physio-mechanical and thermal properties: bulk density (BD_c), apparent porosity (AP_c), linear shrinkage (LS_c), compressive strength (CS_c), refractoriness (R), thermal shock resistance (TSR_c), thermal conductivity(TC) of the produced bricks were determined. The results for BD_c, AP_c, LS_c, CS_c, R, TSR_c and TC of the developed bricks ranged from 1.46– 1.67 g/cm³, 14.0 – 21.4%, 10.5 – 15.0%, 6.0 – 6.8 MPa, 800 – 1010^oC, 4.1 - 5.8 cycles and 0.185 – 0.221 W/mK, respectively. These results are close to those of the control sample which for the same parameters, were 1.60 g/cm³, 20.0%, 10.0 %, 7.0 MPa, 1050^oC, 5.9 cycles and 1.000 W/mK, respectively. Sample B (90 wt% pre-calcined clay, 10% OPC) had the best combined properties evaluated, close to the control samples. The study showed that the clay deposits at COLENG, FUNAAB, Abeokuta and environs can be employed in ovens operating with temperature lower than 1000.