February 17, 2023
The proper mix is crucial to achieve the optimal outcome in concrete spraying. The components of shotcrete (aggregates, cement, water, fine material, chemical additives, and fibers) work together to create a complicated system that affects the finish quality.
Another critical factor is the proper application method, which guarantees that the shotcrete will adhere to the surface and reduces rebound.
Shotcrete acquired by professional concrete contractors plays a crucial role in meeting standards. Follow these guidelines to ensure maximum operator safety and the best results.
Shotcrete is a technique that is used to apply concrete that involves projecting it quickly, primarily onto vertical or above surfaces. Consolidation of the concrete occurs as a result of the application’s impact.
Even though shotcrete’s hardened qualities are comparable to those of traditional cast-in-place concrete, the way it is placed produces a strong bond with the majority of substrates and quick or instant results, especially when working with complex forms or shapes. Compared to traditional concrete placement, the shotcrete method might be more cost-effective and require less formwork.
Wet or dry-mix techniques are used to apply shotcrete. Before being added to the delivery hose, the wet-mix shotcrete process thoroughly mixes all the materials, including water.
When making dry-mix shotcrete, water is injected into the mixture at the nozzle. Shotcrete can be used for new construction and restorations, and works well for curved and thin parts.
Also read: Pitfalls To Avoid In The Shotcreting Process
In underground applications, assessing the risk of falling rock and loose debris is the first stage in preparing the substrate. The substrate must be free of dust and other flexible materials and debris and cleaned with water, air, or a mix of both.
If you are making a pool, there shouldn’t be any standing water at the excavation site. To ensure control of subsurface water movement, the pool bottom should include a layer of stone. It is best to invest in shotcrete services from concrete contractors to make infrastructure and aesthetically pleasing structures such as swimming pools.
Keep the distance between the nozzle and the substrate between 1 and 2 meters. The distance between the nozzle and the substrate determines the impact force that ensures the shotcrete’s adhesion to the surface. Too little space will cause a lot of rebound. The impact force is insufficient at too great a distance to adhere to and compact the shotcrete properly.
There must be support structures for freestanding walls to prevent vibration. These walls need to be carefully attached and secured.
Place the nozzle on the substrate at a 90° angle. The angle between the nozzle and the substrate influences the proper shotcrete compaction and the amount of rebound. To provide a homogeneous effect, the spraying must be done over the entire surface uniformly in circular motions.
Applying layers should start at the bottom of the surface and move upward. The initial layer acts as a support for the excavation and an adhesive link for the subsequent layers. The remaining layers thickness and number are determined by the needs of the job site and the desired homogeneity.
If any plumbing lines are to be part of a vertical wall, they must be firmly fastened in place. To reduce vibration throughout the shoot, run plumbing in the floor stone if necessary and ensure the piping has been pressure-tested. (Take into account the difficulty and expense of fixing a plumbing issue before vs. after the concrete is completed.)
Preventing material buildup in the hoses, nozzle, and additive pump is a crucial component of proper equipment maintenance and cleaning to avoid a more discontinuous flow and ensure smooth operation. The equipment must be thoroughly cleaned before the application can be restarted.
To avoid losing compressive strength and the emergence of fractures brought on by the concrete’s quick hardening, concrete contractors advise keeping the surface damp for at least seven days following application. This procedure is known as curing.
The use of paper or plastic covers and sheets, the sprinkling or spraying of water on the surface, or the addition of particular additives to the concrete mix are a few techniques.
SprayForce Concrete is a COR-certified and BBB – A+ accredited concrete contractor company. We at SprayForce Concrete have a team of ACI-certified nozzlemen with more than ten years of experience in the shotcrete industry. Our experienced team provides structural shotcrete, architectural, soil retention, and infrastructure services. Contact us today for more information.