The endless applications of water jetting: Construction

This article, ‘Application of water in construction’, was included in the EWJI Yearbook 2023. Consult the publication here.

The applications of water jetting are endless. In addition to its uses in areas such as cleaning, it is also a widely used technique in construction. In the following lines, we will deal with different aspects related to its use in construction: the work that can be carried out, the necessary verifications, the machinery and equipment used, the organization of the work, the maintenance of machines and equipment, as well as the basic calculations to ensure efficient results. Safety is also an essential issue in any water jetting work, so some guidelines will be provided to ensure risk prevention. Finally, some indications will be given regarding the environmental effects of the use of this technique in construction, as well as a regulatory framework.

Uses of water jetting in construction

The water jet is used to perform the following actions:

• Marking of roads and paint layers.
• Selective hydrosanning of concrete in poor condition and uncovering of reinforcement and metal elements.
• Joint filling and grout removal.
• Improving the surface quality of materials such as stone, stone or concrete.
• Aesthetic finishes on concrete and natural rock.
• Maintenance of equipment used in construction.
• Removing oxides and coatings from metal structures.
• Hydrodemolition, which allows the selective removal of concrete by overcoming the internal tensile strength of the concrete. Robotic equipment or automated systems are often used in this industry due to its complexity.
• Surface preparation by hydrocleaning: this allows us to recover a surface or prepare it for a new coating, by carefully and selectively removing the material.
• Hydro-cutting, which utilizes high pressure to cut materials such as concrete without creating dust, sparks, vibrations, etc.

Advantages of water jetting in construction

This method enables us to identify a number of benefits, including increased safety, since using high pressure requires less personnel than using manual demolition tools, for example, there is a lower risk of harm; versatile: water jetting can be employed for a wide range of applications on various surface types; preservation of the reinforcement, as it prevents damage to it and gets rid of any necessary corrosion; longer service life, because it is a vibration-free process, so it does not cause microfractures on the surface being worked on, preserving the structural integrity; savings: when compared to conventional cleaning techniques, it uses far less detergent, sometimes to the point where it is not even necessary; good performance: compared to manual methods, good quality work can be completed with fewer resources and in less time; environmental benefits: by reusing the water, the amount of waste and toxic elements generated in the processes.

Organisation of high-pressure work

When dealing with operators, there should always be a minimum of two people doing the same task alternately to prevent weariness. Additionally, there needs to be an efficient mechanism for communicating that is used to carry out the work and was decided upon and communicated in advance.

Due to the high amounts of noise created by the machinery employed, hand signals are the most popular means of communicating. The entire command team must understand these signals, and any gestures must only be used after the water gun has ceased.

The supervisor will be in responsibility of doing all pre-work inspections, securing the necessary work permits, being certified for emergency stops, and maintaining visual contact with the machinery being used. Once responsibilities have been defined, necessary checks should be performed to prevent potential risks.

Steps for a correct implementation of risk prevention in high-pressure works

Effective risk prevention begins with good planning and everyone’s acceptance of responsibility for their part in adhering to the defined work safety standards.

The following phase is to assess any potential dangers, and depending on how significant they are, various actions will be developed. This creates a hierarchy of preventive measures for occupational risks, for which group options are always preferred over individual ones.

Finally, a series of checks will be carried out, including the analysis of the environment, the marking out and demarcation of the working area, the verification of the equipment’s correct operation, the training and qualification of the employees, and the proper use of Personal Protective Equipment (PPE), depending on the works.