Assessing the Correlation between Brick Properties and Firing Hours of Locally Produced Clay-burnt Bricks in Taraba State, Nigeria

The use of burnt-clay bricks is increasing in rural areas because of its availability and low cost. However, the burning of bricks locally at unknown temperatures will likely result in the production of bricks that are unfit for construction purposes. The study assesses the minimum number of days bricks require to attain the minimum stipulated standards for compressive strength and water absorption. The results obtained were compared to the NIS 87: 2000 standards to assess their conformity. From the study results, the mean compressive strength of bricks (1.576 N/mm², 2.306 N/mm², 3.634 N/mm²) at 48, 72 and 96 hours of firing fails to attain the target value of 5N/mm² as stipulated by the NIS building code. However, the mean compressive strength after 120 hours (5.386 N/mm²) attains the stipulated unit value. The water absorption rate displayed similar findings with mean values of 37.12%, 34.2%, 28.88% failing to conform with the stipulated 20% standards. However, the mean of water absorption after 120 hours (21.02%) has no significant difference and hence conforms to the stipulated value. This therefore means that bricks should be burnt far beyond the 120 hours in order to safely conform to 5N/mm² and 20% compressive strength and water absorption respectively.