HIGH PRESSURE WATER JET DEMOLITION OF CONCRETE

Compared to other materials (wood, stone, etc.), concrete is newer and has only been used for the past hundred years. Soon after starting using concrete in construction, the needs for the demolition of concrete began to emerge, either in the context of rebuilding or connection of more modern construction elements or in the demolition of entire worn-out buildings.

Demolition of concrete now represents a significant share of construction work. It was generally considered as hard work that damaged the existing reinforcement. Usually, large cracks occurred during demolition. Due to all this, the quality of work was poor.

Classic methods have also negatively affected the health of employees in the construction industry. It was not until twenty years ago that new concrete demolition techniques have emerged.

One of them is water jet demolition (hydrodemolition). It is a newer approach to demolition, which we researched and presented in the graduation thesis.

In the theoretical part of the graduation thesis, we presented two basic types of demolition more thoroughly. We focused on the demolition with high pressure technology in terms of technical properties, the necessary equipment and the condition of buildings after the demolition.

In the theoretical part, we also included a chapter on the impact of demolition work on health and work abilities of construction employees due to the development of vibration disease. In the empirical part, we conducted a survey to prove the negative impact of working with the classic method of demolition on the health of employees.

We also found that the hydrodemolition method is less often used in Slovenian companies. The second part of the empirical work included a comparative analysis of two construction sites, where demolition of similar dimensions was carried out by different methods – once with the classic method and once with water jet technology.

We compared the cost aspect, the required number of workers, the consumption of the machines and the availability of equipment. We found that demolition with high pressure technology is more affordable, but the costs of initial investments and maintenance are higher.

There is definitely a need for fewer workers, who are less exposed to negative health effects. We believe that all this is still a sufficient argument for greater use of high pressure technology and it should be brought closer to the Slovenian market.