Defining the Concrete Material Properties
Next, we must specify the properties of the concrete in the slab. In this instance, we only have one slab and all the concrete is the same (to generate different types of concrete, see the 'Properties | Concrete Materials' section).
The concrete properties are defined in terms of compression strength, weight, and Poissons ratio. These are used to represent the stress-strain-temperature relationship, defined in accordance with EC4.
Two different generic types of concrete are included in Vulcan - lightweight concrete (LWC) and normal weight concrete (NWC). Each of these has a different function relating the parameters to alternative stress-strain-temperature curves. Warning: The actual weight of the concrete is not included in the analysis and should be defined as part of the loading.
The stiffness boxes allow a representation of the orthotropic characteristics of a composite deck floor, which has significantly stiffer properties parallel to the ribs than it does in the perpendicular direction.
To modify the properties of the slab:
1. Open the 'Properties | Concrete Materials' dialog box.
2. Select the 'Edit' tab.
3. From the drop-down menu, select material number '1' - the slab should now change colour to signify that it is made from this material.
4. Enter the required material properties in the relevant boxes (as shown below).
N.B. The concrete stress-strain curve form is important at ambient and high temperature: