BIM – a concrete choice for multiple construction materials

When discussing the value of BIM and digitisation for construction, a lot of the focus falls on steel – but what about concrete? As the most commonly used man-made material on earth, concrete forms a staple part of many of today’s buildings and infrastructure. Read on to take a closer look at how Trimble’s Tekla software is used for cast-in-place and precast projects…

Automation

It stands to reason that by automating otherwise manual processes, you can not only save time but also reduce the chance of error and improve productivity levels. But how is this level of automation achieved?

Let us take detailing as an example, a process where there can be frequent repetition and, as such, presents the opportunity for standardisation. Within Tekla Warehouse, you can find a library of standard components available for use, from bolts and connections to precast panel ties, meaning you no longer have to waste time individually detailing them.

Another common challenge on any project is change management, whether coming from the client, architect or other sub-contractor. Here, the value of a software with parametric capabilities shines through. Rather than having to spend time manually checking and identifying the impacts of a single change, this can all be done automatically. By making the change in one place, all corresponding components or associated documentation will be updated too, providing added peace of mind that everything is accounted for.

Kilnbridge Construction Services on Canary Wharf’s Water Street Bridge: The required changes were all promptly incorporated within the model, Tekla Structures’ automatic clash detection confirmed the design was correct and constructible. The corresponding fabrication drawings and scheduled were generated within just two days, enabling the new reinforcement to be delivered to site on time.

After the model has been finalised and you’re in the position to produce the relevant drawings or schedules, here again you can benefit from automation. With the central model serving as a single source of information, you can easily and quickly generate the associated fabrication drawings, cut and bar bending documents and concrete pour schedules.

Visualisation

As always, regardless of the material you are building with, visualisation is key. In many ways, by creating the 3D model, you are constructing the building or structure before you reach the site; building it first in the digital environment.

Hewson Consulting on the Luton DART: The use of BIM enables you to assess concrete reinforcement in a more visual way – can this be built? Is that rebar placement possible? Is it constructible? In many ways, it forces you to confront potential design issues head on, as you can physically see the structure in front of you in 3D.

The benefits of this are of course endless and well documented. When it comes to precast, this enhanced visualisation enables you to identify and resolve any potential clashes before they become a problem. After all, once the concrete has been cast and slabs are arriving on site, there’s not much you can do if they don’t fit as intended.

Likewise, for cast-in-place and reinforced concrete, you can benefit from being able to visualise logistics. It’s all well and good having the clash-free structure and its components detailed in the model, but what about physically being able to gain access for the concrete pour? Or what about highly congested areas of rebar, which could cause a challenge for installers on site? Click here to find out how Atkins did exactly that at Hinkley Point C.

Temporary Works

Digital adoption within the temporary works sector remains fairly inconsistent, perhaps due to the overall consideration of temporary works within the wider construction industry, often brought in late on a project and not given the due time it deserves. This way of thinking is of course rather unjust, having an integral role to play in facilitating the safe delivery of the permanent.

From formwork and falsework to scaffolding and propping, temporary works form a large part of the cast-in-place concrete sector. Being able to model, visualise and consider both the permanent and the temporary structures within the one digital environment is invaluable, ensuring a more effective way of working together.

William Hare on the 21 Moorfields development: When it comes to temporary works, the design is often heavily dependent on the permanent works design – and vice versa. For example, the team had to consider the extensive temporary works scheme alongside permanent connections and features, vehicle access zones and site obstructions. Tekla helped to facilitate the effective coordination between it all, enabling us to consider and visualise the temporary alongside the permanent and create the optimum temporary works design.

For example, we have recently collaborated with ScaffPlan on a plug-in tool for Tekla Structures, helping to automate the process of modelling temporary works for concrete. Watch the webinar to learn more about the Scaffplan plugin for Tekla Structures.

Streamlined workflows

As with so many aspects of construction, there are numerous stages and countless companies involved on a concrete structure, from estimation, detailing and design through to bar bending, precast manufacturing, concrete pouring and site construction or assembly. As a result, communication and integration is key and should be at the heart of all digital workflows.

3D models are invaluable for cast-in-place projects, for example. They help you plan how much concrete is needed and how to bend rebar correctly. They also enable you to find mistakes early and use less material, optimising the design; as well as offering real-time visibility on the progress of the project on site. Trimble’s tools make it easy to handle changes and create drawings automatically, making your job simpler and more accurate.

- Hany Salah, Fields Sales at Trimble

By using cloud-based collaboration tools, you can facilitate enhanced levels of communication, with the common data environment allowing precast or CIP models to be synchronised and easily shared with the manufacturer, contractor, engineer or design office.

Thanks to the controlled thread of data connecting all Tekla software solutions, you can also complete the engineered design in Tekla Structural Designer before transferring the design intent directly into Tekla Structures for concrete and rebar detailing. As a result of this software interoperability, teams stand to save considerable time, with the streamlined flow of information preventing the need for work to be replicated or the structure to be modelled twice. Watch the webinar to see how you can design rebar in Tekla Structural Designer and Tekla Structures.

Manufacturing

Precast concrete is very similar to steel construction in many ways, being an example of offsite manufacturing, where the precast slabs are cast away from the main site before being delivered and assembled.

Here, as with steel, the direct integration between software and machine can be invaluable, allowing the data to be exported and transferred from the 3D model to the machinery. With minimal manual input, you can avoid the likelihood of human error, as well as dramatically improving speed and efficiency levels.

Whether it be steel, cast-in-place or existing construction, the use of Trimble technologies (Tekla Structures in particular) allow the user to efficiently interact with many different disciplines that may be present in any job.
The relationship and connection that precast have to these different disciplines is streamlined and made more efficient to all invested parties, thanks to the insight offered by the BIM model and the realisation of how the many materials used in projects can interact without conflict.
For precasting, Tekla Structures offers the user the highly valuable insight of information and data, throughout the contractual period, whether it be a tender modelling, estimating, planning and manufacture, quality control or delivery.

James Dunstan, Detailing and Manufacturing Specialist at Trimble

For a design engineer, the decision to use precast or cast-in-situ concrete can come down to a number of factors. As well as cost and site logistics, it can be driven by the size and complexity of the structure. Precast concrete elements are easily manufactured in controlled factory environments and assembled on-site, providing higher quality control and speed of construction.

However, when a structure reaches a certain number of stories, cast-in-situ concrete is often favoured due to the monolithic structural stability inherent within flat design, which allows fixed floor depths and a maximisation of floor space. A difference of 300mm per floor depth doesn’t sound much, but when multiplied over 30 floors, it provides an extra 3 floors of potential rental space. This is one of the reasons why reinforced cast-in-situ concrete is the structural material used for medium-high rise buildings.

Stuart Campbell, Senior Manager Enterprise Accounts at Trimble

Interested in learning more about the value of Tekla software for concrete? A great example of this in action is Hewson Consulting’s work on one of the Thames Tideway shafts, featuring a combination of precast, cast-in-place and reinforced concrete.

By modelling all components within the one model, the team could consider coordination with the various interfaces and also the M&E elements, visualise site access for the precast installation and highlight potential problem areas of rebar, all of which resulted in a smooth delivery on site with minimal TQs and RFIs received. Click here to read the case study