Dynamic and Static Tests of Plain Concrete Specimens. Report 2. Phase 2: Flexure and Triaxial Compression

The effect of the rate of application of load on the triaxial compressive and flexural strengths of specimens from two concrete mixtures having static compressive strengths of approximately 2000 and 4000 psi, respectively, was investigated. The test specimens were cast as 1-12- by 3-in. cylinders and 6- by 6- by 20-in. beams, which were tested in triaxial compression and flexure, respectively. Triaxial specimens were tested under three lateral pressures 0, 250, and 500 psi in order to establish the relation between shear strength and principal stresses. Dynamic loading of the specimens was accomplished with the rapid-loading, MIT-WES, gas operated impact machine. Resistance-wire strain gages were bonded to the concrete specimens used in the triaxial compression tests to obtain stress-strain relations. Static tests were made on hydraulic testing machine.