Experimental Case Studies on Clay Fired Bricks Compressive Strength

Modern age manufacture technology requires controlled conditions for the burning and pressing of the clay bricks, while in the past these aspects weren't strictly controlled. It is expected to have different behaviours of the brick units for existing masonry buildings, as a result of the diverse fabrication technologies at different moments in time. The present paper presents a case study about the experimental testing on two batches of clay fired bricks. First batch is obtained from an existing structures and the second batch is represented by new bricks. Compression tests were conducted on specimens extracted from every batch of bricks. The experimental tests were carried out according to the current national standard for masonry units. For every tested batch of bricks, the standardized compression strength was computed as an arithmetic mean of the corrected ultimate stress. Following the large dispersion of the results for the specimens obtained from old bricks, the authors consider the standard method to determine the compressive strength of the bricks isn’t suitable for the determination of the brick batch class. Therefore, a series of probabilistic calculation were conducted by the assimilation of the experimental tests results to the processing methods characteristic for masonry. Using these procedures, the characteristic and the 5% fractile value of the compressive strength were determined for every batch of masonry units.