There are many variables to consider when choosing a concrete application method, such as durability, cost, ease of use and resistance. There is no one method superior to the rest, which is why evaluating the pros and cons of every option is necessary to selecting which would best suit an individual construction project’s needs.
One method to consider is shotcreting.
What is shotcrete?
Shotcrete is the process of spraying concrete onto a surface pneumatically projected at high velocity. The particles are compacted into the receiving surface during the application process, creating a strong, uniform layer.
Either wet-mix or dry-mix can be utilized for shotcreting. The dry-mix uses dry ingredients that simultaneously mix with water in the hose as it is sprayed, while the ingredients for the wet-mix are combined before being placed in the hose. Both can be applied vertically or overhead, by hand or remote control.
Here are some of the advantages and disadvantage of using shotcrete in a construction project.
Advantages of using shotcrete
Density
Employing the shotcrete method properly ensures the concrete will be compact and durable. The high velocity at which the mixture is sprayed drives particles into every crevice on the receiving surface, resulting in a mass typically more durable and long-lasting than other methods can provide.
Versatility
Shotcrete is used for reinforcing excavations, lining inside tunnels, mines, and subways, and for theme parks, skate parks, and retaining walls. Limitations when using other methods, like shape, size, depth and style, do not exist with this one. This allows its employment for decorative projects as well, while still ensuring strength, durability and longevity. Shotcreting’s unlimited customization potential makes it popular with forming pools, retaining walls and faux finishes, and constructing high-rise facades.
Resistance
Wet-mix shotcrete in particular has a low permeability and is resistant to many environmental factors, including fire, mold, and worms. The consistent coating is also less likely to be damaged by frost from colder climates. Wet-mix specifically has shown high resistance to thawing after freezing temperatures start to rise, although dry-mix does well too.
Disadvantages of using shotcrete
Application
When employing shotcrete, a quick application is necessary to ensure effective results. If the mixture is not utilized fast enough, it could start to dry beforehand, creating a substance too hard to spray. This leads to an increase in cost for additional mixture, time spent on a project, and potential reparations for any damage in the worst-case scenario.
Expertise
Shotcrete should be utilized by expert operators only. If done improperly, shotcrete could create a situation worse than other methods; a spray is more likely to get into unwanted areas. This could also increase the risk for potential damage and cost of cleanup. Learn about the proper techniques and potential risks of shotcrete before using this method for the first time and consider having an experienced supervisor nearby too.
Dust
The dust content for dry-mix will be a much bigger factor to consider when choosing an application method, as dry ingredients are being used. More exposure to dust drastically increases health risks like lung-related diseases from inhalation of silica, dermatitis and burns on the skin, and eye problems like redness, burning, or even blindness. Make sure to wear the proper protective gear when working with dry-mix to reduce dust-related risks.
Read also: Duties and Responsibilities of Safety Officer in Construction Field
Final Thought
Shotcrete is a limitless method that is ideal for many projects; it can be applied in any direction, makes customization easy, and dries into a durable surface that can withstand almost anything. As long as it is employed by a highly-skilled professional, it is ideal for almost any concrete application project.