Please with a shot

High dynamic loading of structural members made of concrete or masonry may result from explosions or are due to the impact of particles of projectiles. The resistance against the impact of particles or projectiles depends decisively upon the properties and composition of the construction material used for the structural members hit. The Institute for Construction Materials investigates together with the laboratory for ballistics, competence area “weapons technology and protective systems” in the department of Mechanical Engineering of UniBw M construction material properties impact starting with concrete as an initial example. The investigations form a basis for future modelling and contribute to optimization of concrete composition in order to be protective against ballistic impacts.

Figure: High speed photo of a projectile after penetrating a concrete element

Concrete specimens are fired at in the course of the tests conducted at the laboratory for ballistics. High-speed cameras document the tests and help determining the residual energy of the projectile. For analyzing the tests in detail a laser scanner measures all fracture surfaces and as a result the different portions of the energy can be determined. As a result of the project concrete technology parameters can be provided for numerical modelling which accomplished an optimal material selection for improved protection with concrete elements of while maintaining the dimensions.

The research results gained with the impact behavior of sand-lime bricks permits for the first time to produce purposefully sand-lime bricks with enhanced impact resistance on industrial scale.

Figure: projectile stuck in high strength concrete