Monitoring Postpeak Crack Propagation in Concrete in the Brazilian Tension Test

Abstract

The Brazilian tension test is the most common tension test used for concrete, with the advantage of simple setup. However, cracking in the Brazilian test takes place abruptly, which does not allow monitoring of postpeak behavior and crack propagation. In this paper, a novel experimental testing technique that enables monitoring of postpeak cracking behavior using the Brazilian tension test is described. The technique uses additional spring supports in parallel to the test specimen to offload the test specimen incrementally. When the concrete specimen reaches its peak load, the spring supports will resist approximately 80% of the machine load. As the concrete specimen cracks, its stiffness drops, and the spring system increasingly carries more of the load. The load on the specimen is continuously reduced, which slows crack propagation. Comparison with the standard Brazilian tension test without springs shows that the proposed test does not affect the concrete behavior precracking or postcracking but slows down postpeak crack propagation and thus allows monitoring of postpeak concrete behavior in tension.