The Effect of Burnt Clay Brick Production Process on the Compressive Strength and WaterAbsorption Properties

Abstract

Compressive strength and water absorption are important properties of burnt-clay brick. Compressive strength and water absorption are influenced by the manufacturing method and the firing processes of the brick. This study considered the effect of stacking distances of the brick in the field kiln from the heat source on compressive strength and water absorption properties. The bricks were sampled from three different field kiln site locations, Kastina-Ala, Zarki-Ibiam, and Jootar, Benue State Nigeria. Equal distribution for appropriate representation of the bricks in the kiln was guided by quartile (first, second, and third). Ten samples were collected at each stack quartile layer with a total of 30 bricks samples per field kiln. This gave a total of 90 burnt clay bricks samples for the compressive strength and water absorption rates analysis. The result of the analysis showed that the mean compressive strength of the burnt clay bricks decreased from the brick stacked at the lower quartile (Q1) to the upper quartile (Q3) with an average mean value of 4.04 N mm–2 (SD = 1.24 N mm–2). The water absorption property of the burnt clay bricks decreased from the upper quartile (Q3) to the lower quartile (Q1) with the total average mean value of 17.45% (SD = 8.05%). The linear regression analysis between the compressive strength and the distances from the heating source showed p-value = 0.00 and the coefficient of the regression value = – 0.017 while that of water absorption properties gave p-value = 0.095 and coefficient of the regression = 0.029. The result means that the farther the distance of the brick from the fire, the lesser compressive strength, and the greater water absorption properties of the bricks. This was an indication that stack distance of the clay brick from the fire in the field kiln affects the brick quality.