Development of Quality Assessment Criteria for Burnt Clay Bricks of Different Ages Based on Ultrasonic Pulse Velocity Test

Burnt clay bricks are widely used as a construction material in Pakistan, and their testing for quality confirmation is frequently needed for new and old bricks used in existing structures. The destructive testing methods are time-consuming and not always feasible for testing the bricks used in existing structures. The current study investigated the feasibility of using the ultrasonic pulse velocity (UPV) test as a non-destructive technique to assess the quality of both new and old bricks in masonry structures. A relationship was developed after performing the UPV test followed by a compression test on burnt clay brick samples of five different ages acquired from different sources. The acquired brick samples ranged from new to a century old. Consequently, as a novel contribution, brick quality assessment criteria based on UPV were proposed according to which a UPV value greater than 3000 m/s represents an excellent first-class brick whereas a UPV value lower than 2000 m/s shows a second-class brick. Further, the effectiveness of the UPV test to assess the compressive strength of old bricks was demonstrated with a case study of a 100-year-old masonry structure. The research concluded with the remarks that the compressive strength of bricks can be assessed with reasonable accuracy using the UPV test. The developed quality assessment criteria can be used to quickly check the quality of new and old burnt clay bricks