Five common issues encountered by concrete contractors

CGI hand made of MEP, rebar, steel reaches from sky and holds concrete pump helping worker on site

One of the most commonly used man-made materials on earth, concrete is a vital part of the construction industry. However, the practicalities of working with structural concrete, whether precast or poured, can prove highly complex, especially on large projects with tight deadlines or where complex design geometry is required.

Here, Ismail Makda, Business Development Manager - Concrete at Trimble Solutions (UK) Ltd explores five of the common issues encountered by concrete contractors and discusses how incorporating digital technology, including BIM, within their workflow could help provide a solution.

Q: Between the tender process and a contract being awarded, information, such as drawings, material take offs and cost estimates, can be lost. How can contractors ensure that this information is maintained and controlled, avoiding the need for repetition or valuable time being wasted? 

A: Even at the initial tender stage of a project, valuable time, labour and resources are dedicated to creating and presenting a clear bid and concept. During this preliminary phase, concrete estimators will often be presented with initial 2D drawings in a PDF format, from which they will then have to generate accurate material quantities and take-offs for project time and cost estimations – overall, a very long and time-consuming process. 

However, once the contract is awarded and the project moves to the Technical Design stage, all of the previous data, documentation and work can often be lost during this transition, essentially meaning that the design team will have to start from scratch. Incorporating BIM tools, such as Tekla Structures, or an information management platform within a company’s processes can help to eliminate the need for such repetition and time wasting, helping to manage the movement of data further down the DPoW and ensuring only the relevant data is transferred. 

3D model of concrete building next to flowchart showing concrete workflow

Q: Following on from the subject of data sharing, how can concrete contractors effectively communicate with other project parties? 

A: With such a large number of trades and contractors working on any project, it is a challenge to ensure that all parties work together effectively. Indeed, collaboration and communication are vital in order to ensure that all building elements, whether precast and cast-in-situ concrete or steel rebar, frames and beams, are not designed in isolation but are instead considered as a whole. 

The consequences of failing to consider the bigger picture and communicate with other sub-contractors are widely evident, with design clashes between structural components being a common occurrence on construction projects. Discovering such issues on site can be hugely detrimental to the overall project delivery, resulting in additional costs and time delays due to rework being required – something that can be especially time-consuming when it comes to precast concrete or rebar cutting and bending.  

So, how can digital technology help? Since the launch of Trimble Connect, it’s great to see that people within the concrete industry are still getting excited about the benefits a cloud-based platform can provide. Enabling teams to view, share and reference up-to-date project data, drawings and documentation is incredibly valuable, encouraging greater communication and providing visibility of the project as a whole.

Screenshot of Trimble Connect showing 3D model and documentation associated with it

Such a data-sharing platform also opens up enhanced communication channels between project parties, providing a streamlined approach as opposed to lengthy email chains. In turn, this will also aid problem-solving on a project, for concrete contractors can easily discuss any potential problems with other contractors, being able to pinpoint exactly where on the model the issue is, add comments and even assign a task to a specific person on the project.  

Q: Temporary works, including formwork, can often be overlooked during the design process. How can contractors more quickly and efficiently plan, design and manage formwork operations?

A: This is a real issue within the industry. Indeed, we often hear from formwork contractors and suppliers who report being brought onto a project last minute and provided with limited notice and/or information to deliver the formwork design drawings. 

It is for this reason that we have been working hard over the last few years to develop tools within Tekla Structures specifically for formwork contractors and suppliers, providing them with the ability to design formwork in a quick, efficient and largely automated manner. From a library of ready-made common formwork components and the flexible insertion of different formwork panels, corners, shoring and pouring platforms to the ability to automate repetitive tasks, such as the placing of formwork ties and clamps, with digital processes formwork contractors can benefit from intelligent, automatic tools. 

Despite often being overlooked due to its temporary nature, formwork can in fact be the most time-consuming part of any cast-in-situ concrete construction project. Therefore, the ability to design and model the required formwork in a way that is both quick and highly accurate not only prevents project delays due to design errors being discovered on site but also allows for a more streamlined process, with the site able to be efficiently and successfully prepared ready for the concrete to be poured. 

Tekla Structures 3D model of formwork, clamps, props and platforms

Q: Whether coming from the architect’s office, client or elsewhere within a project, last minute design changes are extremely common on any construction project. However, how a contractor deals with such changes can have a significant effect on the overall project delivery…

A: Yes, last minute design changes can, understandably, result in significant consequences for the delivery of a project, especially if contractors have not digitised their processes or are still working in 2D only. Regardless of the building material, change management can be a hugely stressful challenge, with considerable time needed to re-design the component or section in question, ensure the new design is constructible within the wider context and then update all associated precast or rebar fabrication drawings. 

Kilnbridge, the concrete contractor, experienced exactly this on the Water Street Bridge project in Canary Wharf, but as a result of its BIM processes the company was able to efficiently resolve the last minute changes. Two weeks prior to a key concrete element being constructed, the permanent works engineer noted that the design calculations hadn’t correctly accounted for the loading from a ship impact, meaning substantial changes in the concrete reinforcement were required. Fortunately, Kilnbridge was able to promptly incorporate the changes within Tekla Structures, confirm that the new design was constructible and the corresponding fabrication drawings and schedules were generated quickly and efficiently. 

What’s more, by linking BIM software to Rhino and Grasshopper, concrete contractors can even further improve their ability to react efficiently to last minute changes, for incorporating parametric and data driven design within the digital workflow makes it even easier to adapt the model. Design teams would be able to update the parameters of the particular concrete component or rebar section with the new required figures/data in Rhino, with the associated model, along with all documentation and drawings, in Grasshopper and Tekla Structures automatically updating. 

Rhino Grasshopper screenshot showing many nodes next to Tekla Structures model

Q: Inefficient information transfer, incorrect documentation and human error at the concrete design, fabrication and pouring stage can all prove hugely detrimental to a project’s delivery. How can concrete contractors work to minimise such risks? 

A: The amount of information and documentation contained on any construction project will be significant, making it difficult to ensure that the correct data has been transferred to the correct stage or department at the correct time, especially if a contractor has not digitised its workflow. What’s more, with a human workforce, the potential for human error has to be an expected risk for contractors to consider, whether at the formwork design, pouring or precast or rebar fabrication drawing stage.

By moving to a digital workflow, this human element of risk is, for the most part, removed, with features such as clash detection, smart information management and automation all stepping in. A completed Building Information Model will contain an immense amount of information-rich data, from which all pour, precast fabrication and rebar bending drawings and schedules can then be generated, providing concrete contractors with the assurance that all resulting data and documentation will be accurate, being recycled throughout the workflow. 

Q: What does the future hold for concrete contractors? 

A: With technologies moving ahead at a rapid pace, many contractors risk getting left behind should they not avail themselves of all the different efficiencies embedded within such technology. Indeed, in the current climate, we are seeing an increasing number of contractors going under due to the increasing pressures within the construction industry. 

With the emergence of technology such as point cloud scanning, augmented reality, 3D printing and machine learning, it represents a marked change in how contractors can obtain, transfer and communicate information. Slowly but surely, we are seeing the 3D BIM way of working becoming the norm, with those who have embraced and positively adopted it already reaping the project cost savings and the enhanced efficiency and profitability. 

Point cloud visualization showing clash checking of existing precast panel against model

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