The construction industry faces major challenges regarding sustainable resource

management, particularly in relation to concrete. Concrete production is

resource-intensive and significantly contributes to carbon dioxide emissions, while

demolition projects generate large volumes of residual concrete that are often disposed

of as waste. This unused material presents both an environmental problem and a

potential resource. Against this background, the issue is framed around how demolition

concrete can be better utilized instead of being wasted.

The purpose of this thesis is to investigate the potential of converting demolition

concrete into recycled aggregate for use in new construction projects. The study also

focuses on a comparison between residential construction and infrastructure projects in

order to highlight differences in requirements and challenges between the two sectors.

To achieve this purpose, a literature review was conducted, examining current research

and industry reports. These provided data on the technical properties of the material,

such as compressive strength, density, and water absorption, which were compared to

natural aggregate materials. Environmental and economic aspects of using recycled

concrete were also addressed. Additionally, interviews with industry professionals

(engineers and contractors) were carried out to gather practical insights, assess the

current industry attitude, and identify barriers to implementation.

Recycled concrete aggregate (RCA) often exhibits lower technical performance than

natural aggregate. Water absorption can be significantly higher, and compressive

strength tends to decrease at high replacement levels. Nevertheless, the technical

analysis in this study indicates that with proper crushing methods, sorting, and possible

additives, recycled aggregate can meet relevant strength and quality requirements. In

infrastructure projects, RCA is considered suitable for replacing virgin materials to a

large extent without compromising structural integrity. In residential construction,

higher demands are placed on material quality in load-bearing elements and aesthetics.

Therefore, recycled concrete can be used selectively in such projects, primarily in

non-structural components. Several sources suggest that up to 30% replacement is

feasible without significantly compromising performance.

From an environmental perspective, increasing the use of recycled concrete is

beneficial. Replacing part of the virgin aggregate reduces the need for natural gravel and

crushed rock, thereby conserving natural resources and reducing waste volumes.

Several analyses also indicate that carbon emissions and energy use in production can

be substantially reduced. The economic analysis shows that concrete recycling can be

cost-effective in the long run, especially when processed locally, where cost savings

may be achieved. At the same time, treatment costs must be taken into account.

Interviews with industry professionals reveal cautious optimism regarding RCA,

primarily driven by sustainability goals and potential cost savings. However, the need

for clearer standards, improved quality control, and economic incentives was

emphasized in order to increase practical implementation.

In conclusion, this thesis shows that residual concrete from demolition has the potential

to evolve from a waste issue into a sustainable resource for the construction sector. With

the right conditions, recycled aggregate can contribute to both reduced climate impact

and increased resource efficiency, especially in infrastructure applications.