In each release of Revit we are now seeing a continuous trickle of new features and improvements to the Reinforced Concrete modelling and detailing capabilities. Most of the ‘standard’ features are already firmly established and now Autodesk move on to the reinforcement of complex concrete forms and cross platform workflows. As discussed in my previous post on the Revit 2018 steel detailing features, Autodesk have some stiff competition in this area and are quickly closing the gaps. Also an expected delivery of a BIM project is a complete 3D model and it may no longer be appropriate to issue flat 2D drawings and a bending schedules. Some of the new tools will be very useful in Civil projects such as Tunnels, Bridges and roadside structures where the geometry is likely to be curved and sloped.
I have tested all the new features and will start with the main function of the reinforcement of complex concrete features. In the image below I was able to add 4 L bars in plan and then create a varying range to the inverted truncated pyramid shape.
I also tested the varying distribution on other native Revit in-place families and did struggle with twisted and double curved objects but in general, this new function is very useful and saves a lot of time. In fairness I would image that you would need extra control over double curves and twists and likely have to use something like Dynamo to place ‘real’ reinforcement in a logical way.
Another refurbished tool is the Rebar graphical constraints. This tool enables reinforcement bar to be constrained in 3D views as well as the traditional 2D views. The user can selected the rebar plane or the end points of the bar and then constrain this to a relevant plane on the host element. In the image shown below you can see the bar plane constraint being set and then the end of the L bar to the front face.
The reinforcement bar also has Bar Handles that allows the physical leg lengths to be dynamically edited which is quite handy when you need to drag the bar around in the 3D view. The graphical constraints will still show the check box to snap the bar to cover.
You can now directly import a 3D solid from another CAD application (AutoCAD, Rhino, Trimble SketchUP & Bentley Microstation) and host reinforcement directly into the elements. This is a neat workflow when coupled to tools such as Infraworks. You can create a bridge and then export this directly to Revit and then add reinforcement.
In the example above a 3D ramp has been modelled in AutoCAD and then directly imported and reinforced within Revit. In practice this is only useful for single elements and not an entire bridge as you will need to import each solid separately and then set the correct Sub Categories and parameters.
In conclusion Autodesk continue to strengthen the Revit application and make the legacy 2D detailing a think of the past.
lawrenceH
Autodesk Revit Structure 
One question: How do I add longitudinal bars in the ramp above? Is it done manually or can it be a set of curved bars?
It can be done fairly easily with Dynamo and as a rebar set. You can get Dynamo to pick the edge and offset. This can then be divided into stock lengths and then you can add the rebar.
Have you tested it? This user seems to have trouble with adding longitudunal rebars with Dynamo:
https://forum.dynamobim.com/t/spiral-ramp-rebar/9697/14
I have checked this using straight bars that will naturally deflect on fixing. I didn’t use a bar with a radius as the helix is fairly large.