Reusing construction materials has become increasingly significant in the context of the Netherlands’s goal to achieve a fully circular economy by 2050. This thesis provides a guideline for the reuse of masonry, emphasising the transition from traditional demolition methods into techniques that facilitate the reuse of masonry elements. The research explores the development of masonry, current practices, and future perspectives, highlighting the environmental gain and durability proceedings.

Masonry, a cornerstone of Dutch residential construction, offers significant potential for reuse due to its durability and historical prevalence. Despite innovations like drystacking and prefabrication, traditional masonry remains dominant. This study underlines the urgency of enhancing masonry reuse in light of the projected increase in new housing construction and subsequent demolitions. The research identifies a gap in the reuse methods of masonry, proposing an approach of cutting out panels from exiting walls for incorporation into new projects.

The thesis begins with a historical overview of masonry and its separate elements, mortar and brick. It traces its development from Roman times to the present. Early masonry in the Netherlands saw the use of tuff stone and brick, evolving through various phases influenced by technological advancements and changes in construction methods. The introduction of cavity walls, the development of different brick bonds, and the use of various mortars are detailed, highlighting the transition from masonry as a structural element to its current role as a (decorative) façade.

Innovations in masonry construction are examined, focussing on drystacking, robotics, and prefabrication. Drystacking allows erecting masonry facades without mortar, facilitating easy disassembly and reuse. While promising, Robotics in masonry construction face challenges in widespread adoption due to the complexity and precision required. Prefabrication, though historically significant, remains underutilised in modern construction.

The thesis analyses the current stock of buildings in the Netherlands, emphasising the potential of masonry reuse. It discusses the materials flow, highlighting the substantial use of bricks and concrete in new construction. The research outlines the demolition trends, noting that older buildings, particularly those from the post-war period, are prime candidates for material recovery.

A significant portion of the thesis is dedicated to the practical aspects of masonry reuse. It describes the process of removing masonry elements, including desk research, visual inspection, and destructive tests. Techniques for sawing, hoisting and transporting masonry panels are discussed, providing a step-by-step guide for practitioners. The study also addresses storage and implementation, emphasising the need for proper handling to maintain the integrity of the reused material.

Durability is a critical concern in masonry reuse. The thesis evaluates structural and climate durability, assessing the properties of masonry elements under various conditions. It explores the impact of frost/thaw cycles, improper joint application, and strategies on the longevity of reused masonry. The research employs DIANA modelling to simulate the structural behaviour of masonry panels, providing insight into their performance during non-conventional boundary conditions of lifting the element from the existing structure.

The environmental impact of masonry reuse is quantified through a life cycle assessment (LCA). The study compares the environmental burdens of reused masonry elements with traditional buildings and reusing masonry bricks. It highlights significant reductions in CO2 emissions and total MKI value in both comparisons.

The thesis concludes with practical recommendations in the form of a guideline, encouraging a shift towards more sustainable building practices. The research emphasises the importance of quality control and standardisation in reusing, ensuring that reused material meets current regulations and performance standards.

By addressing the technical, environmental, and practical aspects of masonry reuse, this thesis contributes to the broader discourse on sustainable construction. It provides a valuable framework to enhance masonry reuse, aligning with the Netherlands' ambition for a circular economy. The guideline presented in this thesis research aims to facilitate the adoption of masonry reuse practices, promoting environmental conservation and resource efficiency in the construction sector.

Waste generation is one of the main environmental problems and is a result of the current linear economy. Materials/elements are used whereafter they are wasted which is a problem considering the finite material supply on earth. Therefore, the current linear economy needs to move towards a circular one in which materials are reused and thus kept in the circle. However, reuse is still not a common practise. This is due to the fact that there are no insights in the structural feasibility, potential savings on environmental impact, and costs related to reuse. Besides the lacking knowledge about the different aspects there is no clear image where the potentials for reuse are located within the sector.
The goal of this research is to give insights in the reuse potentials and to find opportunities within the sector. This research started with a material flow analysis to find promising material flows in the sector. In this material flow analysis it was found that the demolition of office buildings is responsible for a big portion of the outgoing material flow and the majority of the ingoing material flow is related to the new construction of serial houses. In the analysis it was found that the elements with the highest ECI and mass are floor elements. Next the available floor elements coming from office buildings and the floor elements needed for the construction of serial houses were examined to check possible matches. It was found that new plank- and hollow core slab floors used in serial houses can potentially be substituted for reused monolithic- and hollow core slab floors out of office buildings.
Thereafter, two different tools were developed. One related to the reuse of monolithic floors and one related to the reuse of hollow core slab floors. These tools are means to give insights in the reuse potentials considering the structural feasibility, potential savings on environmental impact, and costs. Different cases were checked using the tools and the following results were found:
-In all cases it was structurally feasible to use reused floors coming from office buildings in the new construction of serial houses.
-When reused floor elements are used it is possible to save 40-90% on environmental impact.
-Reused floor elements can be cheaper or more expensive as new floor elements.
These results are promising and hopefully contribute to an acceleration of reuse in practise. The research states where the potentials for reuse are located in the sector and presents two tools which check the reuse potentials considering structural feasibility, environmental impact, and costs.

We are currently facing a transition of economy. Previous years were focused on a linear economy, consisting of the make-waste concept. The products that are made with raw materials are thrown away after its use. Unfortunately the Earth does not contain an unlimited source of materials and we need to focus on reusing materials. Concluding to create a circular economy in which waste does not exist at all.

The goal is to start with reusing as of today, instead of in the future. In other words, using the current existing elements. However, to do so it must be known which elements are available. Therefore, a data analysis has been done on the current existing structures as well as the future perspective. These analyses combined concluded in a common scope, visualized as a Lego box. This Lego box does not only consist of all the current existing structures (within the determined scope), but also provides a future perspective on the demolishing plans in the near future. Based on a time-consuming manual research a variety of nearly 70 viaducts have been examined. This lead to the summarization of 5 different girder categories: Box girders, inverted T-girders, Infilled girders, T-girders and remaining.

With the specific girders known, design applications can be created. The focus on these applications is to think outside the box and reusing a girder in a different function than the original purpose. The design applications are created with a brainstorm session. For this session multiple different broad-minded individuals had been invited for an open discussion which concluded in over 20 different design applications. Thereafter, these applications have been examined with the help of an MCDA, based on the three main criteria. This MCDA is executed with the help of multiple different experts with a background regarding one of the three main criteria. With these expert judgements the total amount of design applications have been demarcated to a top 5. Reusing a girder as: Bicycle bridges, (non-)residential buildings, retaining walls, sound barriers and culverts

In conclusion, this thesis provides valuable outputs and the first impressions regarding reuse in another application seem at least interesting. With the different impact factors determined, the possibility looks very promising. It can be stated that reusing in general will be better for the environment, as well as for your own wallet. Reusing a girder as culvert can in theory be seen as a good reuse application, but not higher in a general value than reusing again as a girder. This is based due to the fact that using the girder as a culvert will take more research in practice, especially regarding structural aspects. However, from this thesis it the first impression conclude in the fact that the impact in costs as well as environmental impacts are bigger when reusing the girder in another function