The Ball-on-Three-Ball (B3B) Test – Application to Cement Paste and Mortar

While originally used for ceramics, the ball-on-three-ball (B3B) test has shown value for use with cementitious materials. The B3B test uses disk-shaped samples that can be sectioned from a cylinder, which allows a large number of samples to be tested to provide information on statistical repeatability. Additionally, this test is also well suited for use in some cement paste degradation studies. In this research, cement paste and mortar samples made with standard ASTM sand or natural sand were tested using the B3B test. The results showed that the B3B test has less than 10 % variation in flexural strength for cement paste and mortar. Data analysis using statistical Weibull theory indicated that the B3B flexural strength is typically lower than four-point bending flexural strength; however, this can be explained by size effect considerations. Recommended testing procedures were given.