Dynamic test devices for analyzing the tensile properties of concrete

Owing to their low tensile failure strain, concrete is a difficult material to test under dynamic tensile loading. Indeed, conventional testing apparatuses such as high-speed hydraulic presses or Split Hopkinson Bar facilities rely on a mechanical balance of the specimen implying a short round-trip time in the specimen in comparison with the...

Simplified stochastic modeling of concrete spalling due to fire

Predicting spalling of concrete due to fire loading is undoubtedly a complex task to come across. Existing numerical models are dealing with the phenomena on different complexity levels of describing the physical/chemical processes and material behavior. But still they do not take the highly stochastic nature of these processes into account....

Shock propagation in a cemented tungsten carbide

WC-based ceramic metal composites (cermets) are of great importance in both armor and munition design due to the combination of properties imparted by the presence of two different phases. WC-Co cermets are of interest in this area due to the hardness and strength imparted by the WC phase while the cementing Co matrix acts to increase plasticity...

Validation of FEM models describing moisture transport in heated concrete by Magnetic Resonance Imaging

Fire safety of buildings and structures is an important issue, and has a great impact on human life and economy. One of the processes negatively affecting the strength of a concrete building or structure during fire is spalling. Many examples exists in which spalling of concrete during fire has caused severe damage to structures, such as in the...

Effects of polypropylene fibres in concrete: Microstructure after fire testing and chloride migration

Explosive spalling of pieces of concrete from the heated surface is considered to be the most dangerous effect of damage of concrete subjected to intense fire attack, especially when it occurs in restricted areas such as underground tunnels. Recent investigations have revealed that the amount of explosive spalling and the extent of cracking can...

Numerical modelling and experimental assessment of concrete spalling in fire

In this paper, the phenomenon of spalling of concrete in fire has been studied using a numerical model. Spalling is the violent or non-violent breaking off of layers or pieces of concrete when it is exposed to high temperatures as experienced in fires. The types and mechanisms of spalling have been explained. A numerical model has been developed...