Applications of 3D printing in civil engineering.

Introduction/Definition.

The world of civil engineering has witnessed a groundbreaking revolution in recent years: the integration of 3D printing technology. this innovative approach has the potential to transform the way we design, construct and shape our built environment. With its ability to fabricate complex structures with unparalleled precision, speed, and cost-efficiency, 3D printing is paving the way for a new era in civil engineering.

3D Printing in Civil Engineering can be used to create construction components or to print the entire building.

3D printing is basically the construction of 3D objects from a CAD model or a digital 3D model.

It refers to various technologies that use 3D printing as a core fabric method for fabricated building or construction components.

Applications of 3D printing in civil engineering.

The most valuable feature of 3D printing is its ability to create the most complex geometric shapes easily. And create the additive layers to form the structure. With this kind of “anything is possible” feature and the speed by which it makes them, it will advance the course of Civil Engineering.

Enhancing Road Repair and Resilience Techniques

Road maintenance often falls under the umbrella of civil engineering responsibilities. Members of the public typically appreciate potholes getting repaired, but they don’t like how the heavy equipment needed for the job creates congestion for the traffic flow. Fixing the roads may soon become easier — and substantially more mobile — thanks to 3D printing.

A machine called the Addibot is a streamlined and portable 3D printer originally designed for ice resurfacing. However, its inventor is tweaking the design to make it compatible with tar and asphalt.

Keeping the roads in good condition also may require civil engineers to get to the bottom of what’s causing them to break down. In areas of the country with Amish populations, the buggies and horseshoes can be hard on the pavement.

One solution that may require 3D printing is a screw-in stud for the horses to wear. It has a larger surface area than what the horses used before and might be kinder to the pavement. Users could also change the studs for different seasons.

These options take a different approach to road infrastructure maintenance. But, both examples show how 3D printing could play a key role in fixing issues or making them less likely to happen so often.

Improvements in modes of Bridge construction

An example is the first concrete bicycle bridge opened up to users in 2017 in the Netherlands or when Shanghai, China printed the longest 3D bridge (26 meters in 450 hours). These bridges were an important milestone in a battle that was turning to be one of feasibility. It is showing the world that Additive manufacturing can unlock higher levels of human development, including emergency bridges constructed in seconds, quick response to disasters, and many more.

Advantages of 3D printing

Eco-Friendly

3D printing can be considered eco-friendly due to the use of recyclable materials like metals and thermoplastics. Parts can also be printed exactly where they are needed instead of being shipped from a centralized heavy-manufacturing plant. This eliminates the significant energy costs associated with transport. The additive nature of 3D printing also results in less wastage.

Quick Prototyping

The low cost and print-on-demand features of 3D printing make it ideally suited to developing prototypes. A 3D printed part can be produced in less than a day. This allows for rapid iteration of new concepts without the up-front tooling cost typical of other common technologies like injection molding.

Accessibility

3D printing has gained widespread adoption over the past decade. This can be traced back to some key patents held by Stratasys expiring in 2009. The open-source nature of 3D printing since then has allowed for the development of low-cost consumer 3D printing machines. The increased user base allowed for the creation of a large body of easy-to-access online knowledge on best practices, fault finding, and general optimization techniques for 3D printing. This has allowed for unprecedented accessibility that is very rare in other technology spaces.

Strong and Lightweight Components

3D printing only adds material exactly where needed. For example, internal volumes can be made to have mesh structures that are dense where stress concentrations are high and less dense in areas where they are low. Techniques like topological optimization and generative design also produce parts whose geometry is optimized for a specific load case and remove material wherever it won’t have a structural benefit. These techniques often produce parts with highly complex, organic-style geometries which makes them impossible to manufacture with other technologies.

Faster design and Construction

The construction speed that can be achieved through 3D printers is advantageous using this technology in comparison to the classic construction methods.

It is so because 3d printing is easier and quicker than the classical methods of construction.

From the preparation of the blueprint to the final product, 3D printing incorporates designs and ideas quickly.

Complex designs can be prepared from a CAD model and be used for 3D printing. In routine, it takes just a few hours for the 3D printing to complete.

Reasonably Priced

The 3D printing process is reasonably priced when compared to other manufacturing technologies like injection molding. This is especially true at low-to-medium production volumes and high part complexity. This is because 3D printers are priced from $200, with used 3D printers being even cheaper. Materials can also cost as little as $15 per kg – for ABS for example. Although, 3D printing materials are generally more expensive than the comparable baseline raw material cost. This is due to the requirement to prepare the raw material for the specific printing process, i.e. filament spools for FDM and fine powder for SLS. Despite this additional raw material cost, 3D printing makes use of less material due to not being completely dense

Better Quality of Objects

The problem that most designers face is how to construct projects as systematically as possible. Most additive construction instruments do the building inbuilt one-step process.

The process is very efficient as it does not require any interference by the machine operator during the construction phase. The machine takes only a few hours/days to achieve the results once the CAD blueprint is finalized and uploaded to the machine.

The designer has full control over the final product.  The dependence on various construction processes like painting, welding, etc is reduced as the machine produces a part in just one step.

Waste Reduction

3D printing produces very little waste. This waste is typically in the form of support structures that are removed after printing, in the case of SLS-printed parts. These support structures are optimized to be as lightweight as possible. Subtractive manufacturing techniques require the removal of large volumes of material which produces significant waste. Additive technologies like 3D printing are designed to selectively add material only where needed. This then offsets the minimal waste produced by support structures.

Print on Demand

3D printing requires a very limited setup to begin printing. The setup process and the 3D printing machine are the same regardless of the type of part being printed. All that is required is to convert the 3D model of the part, usually handled with either OEM or third-party software. After the conversion is complete, the file is loaded into the printer through a USB-A connector, wirelessly, or an SD card. The material is then added to the printer, typically either as a liquid photopolymer, a filament, or a powder. Thereafter the print process will continue without any human intervention. When the part is complete some post-processing, like the removal of support structures, may be required. On-demand cloud services simply require a 3D model and will 3D print and ship your item without the need to invest in a 3D printer.

Personal Satisfaction

3D printing rubs shoulders with the likes of woodworking and pottery as one of the most rewarding hands-on hobbies.

From assembling the printer to firing off that first print, by way of tweaking settings and making modifications to getting over those troubleshooting humps, there’s a genuine pleasure in chasing down that perfect print, acquiring skills, and learning the ins and outs of your 3D printer.

If you’re the type of person who loves self-led discovery and finds learning fun, few hobbies deliver quite as much personal gratification as 3D printing.

Speed

3D printing has already shown that it can build a home or building from the ground up in a matter of days. That’s a significantly faster timeframe than conventional construction, which can take months and years to fully construct a commercial building. According to Marco Vonk, Marketing Manager at Saint-Gobain Weber Beamix, “You save about 60% of the time on the jobsite and 80% in labor.

Waste reduction

Worldwide construction waste currently totals more than 1 billion tons each year, and according to Construction Dive, this number is expected to double by 2025. While 3D printing won’t be able to solve all of the construction waste problems, it can help. This is largely because 3D printing is an additive manufacturing process that only uses as much material as is necessary for creating a structure. When paired with other waste-reducing processes and building methods like prefabrication and lean construction, the potential of a waste-zero building seems all the more likely.

Reduced error

According to OSHA, more than 5,000 workers are killed on the job each day. Because construction would be more programmable and automated, worker injuries and fatalities would likely decrease if 3D printing was incorporated onto the jobsite.

Besides less waste being created by humans on construction sites, 3D printing can also give construction sites an opportunity to be nearly error-free. 3D printing can produce high-quality structures for clients and reduce the number of accidents on construction sites. Because printers can operate through nights and weekends, humans are often only responsible for supervising the machines.

Recycling

Another environmental benefit of 3D printing is that you can use recycled materials in your projects. 3D printers create lattice patterns with materials, so recycled plastic can create a sturdy structure. Construction sites can also use other reusable materials like recycled concrete.

Innovative solutions

Whereas traditional construction methods involve reusing plans and templates, 3D printing can create custom solutions. Architects can design innovative buildings using new architecture software and the 3D printer can create them. For example, if clients want a specific design or unusual shapes for their homes or offices, you can rework the models in the software and reprint them until you construct the final product. You can do this with little impact on cost or human effort.

Completes the job

3D printers can create entire buildings, including houses and offices. This is typically more cost-effective, better for the environment and quicker than traditional construction. Towns may also consider using 3D printing for other infrastructure needs such as stairways, bridges, railings and other community projects.

Disadvantages of 3D printing in construction

3D Printing Technology is Expensive

3D printing equipment and materials cost make the technology expensive. Industrial grade 3D printers are still expensive costing hundreds of thousands of dollar, which makes the initial expenses of using the technology very high. For a single machine, capital investment starts in the tens of thousands of dollars, and can increase to as high as hundreds of thousands of dollars or more. Also, the materials used in commercial grade 3D printers are costly compared to product materials used in traditional manufacturing.

Labor shortage

3D printing technology can make designs and prototypes in a matter of hours as it uses only one single step. It eliminates a lot of stages that are used in subtractive construction. As a result, it doesn’t require a lot of labor cost. As such, adopting 3D printing may decrease construction jobs. For countries that rely on a large number of low skill jobs, the decline in construction jobs could dramatically affect the economy. It’s likely that robotics will have a much larger impact here.

The construction sector is booming, and skilled workers are in high demand. The only problem is that there are not enough of them.

Even considering the labor shortage, 3D printing requires an even more specific skill set that would have to pull from a slimmer and more niche group of candidates. Construction labor shortages are already a problem, and finding qualified workers to employ in 3D printing construction environments could prove to be even more challenging in the future.

High Energy Consumption

According to research by Loughborough University, 3D printers consume approximately 50 to 100 times more energy than injection molding, when melting plastic with heat or lasers. In 2009, studies at The Environmentally Benign Manufacturing, a research group dedicated to investigating the environmental impacts related to product manufacturing, showed that direct laser metal deposition uses 100 times as much electrical energy as traditional manufacturing. For mass production, 3D printers consume a lot of energy and are therefore better suited for small batch production runs.

Limited Materials

While 3D printing is a significant manufacturing breakthrough, materials that can be used are still limited, and some are still under development. For example, the 3D printing material of choice is plastic. Plastic is preferred as it can quickly and easily be deposited down in melted layers to form the final product. However, plastic may vary in strength capacity and may not be the best for some components. Some companies offer metal as a material, but final product parts are often not fully dense. Other specialized materials including glass and gold are being used but are yet to be commercialized.

High costs

Perhaps the biggest challenge to the widespread adoption of 3D printing technology on construction sites is the high cost of purchasing or renting such equipment and the logistics involved in getting these large 3D printers to the work site. 3D printers are costly, and that upfront purchase cost doesn’t include materials or maintenance. Right now, it’s difficult for many construction professionals to justify 3D printing’s cost over the technology’s benefits.

Harmful Emissions

3D printers used in enclosed places such as homes can generate potentially toxic emissions and carcinogenic particles according to researchers at the Illinois Institute of Technology. Their 2013 research study showed that 3D desktop computers could emit large numbers of ultrafine particles and some hazardous volatile organic compounds during printing. The printers emitted 20 billion ultrafine particles per minute using PLA filament, and the ABS emitted up to 200 billion particles per minute. Emitted radiations are similar to burning a cigarette, and may settle in the bloodstream or lungs posing health risks including cancer and other ailments.