Analysis of the geometrical imperfections of a dry-stacked masonry block based on Miscanthus

in Construction and Building Materials (2021)

Binary blended cement pastes and concrete using gravel wash mud (GWM) powders

in Construction and Building Materials (2021)

Luxembourg 2050 - Prospects for a Regenerative City Landscape : Report Phase 2

Report (2021)

Design model for dry-stacked and demountable masonry blocks

in POWERSKIN Conference Proceedings (2021, April 09)

The construction industry around the world produces a large part of inert wastes mainly coming from building demolitions. Facing to this envi-ronmental challenge and considering the new policy initiatives ... [more ▼]

The construction industry around the world produces a large part of inert wastes mainly coming from building demolitions. Facing to this envi-ronmental challenge and considering the new policy initiatives supporting the designing of sustainable buildings, dry-stacked masonry comes forward as a promising solution since components can be dismantled, saved in a component bank and reassembled on new sites. The speedy growth of the construction industry, the increasing importance given to the complete life cycle of buildings and the evolution of construction technics have led to the development of dry-stacked masonry structures. Mortarless masonry structures minimise skilled labour requirements and improve construction productivity. However, despite these advantages, there are no design standards providing guidelines to assess the load-bearing capacity of dry-stacked masonry block, which therefore limits its use in construction. In an attempt to fill this lack, the current paper investigates the load-bearing capacity of dry-stacked masonry and its influencing parameters. The effects of the geometric imperfections such as height imperfections and bed-joint roughness have been analysed as well as a mitigation strategy. Then, based on experimental evidence, a design method has been proposed for dry-stacked masonry solicited by axial compression. The developed design methodology provided promising results, with 93% of accuracy in the prediction of the dry-stacked masonry’s’ load-bearing capacity. [less ▲]

Modelling of mineral construction and demolition waste dynamics through a combination of geospatial and image analysis

in Journal of Environmental Management (2021), 282

As the construction sector is shifting towards circular economy models, the role of mineral construction materials as main waste fraction in terms of volumes is crucial. A characterization of this mineral ... [more ▼]

As the construction sector is shifting towards circular economy models, the role of mineral construction materials as main waste fraction in terms of volumes is crucial. A characterization of this mineral stock, as well as the waste derived from it is decisive in ensuring the application of the best practices of circular economy. This paper describes a methodology for assessing the mineral building stock through a combination of geospatial and image analysis. By analysing old topographic maps, buildings are grouped according to their building age into different typologies and based on these maps the construction and demolition activity is evaluated. The mineral stock is assessed and estimations of the mineral construction and demolition waste (CDW) is generated for different stochastic scenarios. This methodology is applied exemplarily on the country of Luxembourg. It was found that the total mineral construction stock for Luxembourg is 276.75 Mt and has been growing at a rate of 20.81% to 24.39% in the last 30 years. Furthermore, the study identified a mean age of the urban building stock of about 60 years and a typical maximum building lifetime of 122 years. Based on the stochastic projections the mineral CDW generated from the existing building stock is expected to be up to 226.9 Mt by 2100, while if future building scenarios are considered, it can be as high as 885.3 Mt. The annual CDW production is expected to be sufficient for a viable concrete recycling activity if regulations on the waste volume flows are made available. [less ▲]

Extended Producer Responsibility in the Construction Sector through Blockchain, BIM and Smart Contract Technologies

Poster (2020, December 09)

Despite the enormous amount of raw or secondary materials flowing within the construction industry, the actual available volume of materials and their respective End-of-Lifecycle (EoL) treatment is not ... [more ▼]

Despite the enormous amount of raw or secondary materials flowing within the construction industry, the actual available volume of materials and their respective End-of-Lifecycle (EoL) treatment is not regulated nor uniform. On top of that, the EoL responsibility of different stakeholders after the future building deconstruction is confusing and disputable. Consequently, different sustainability policies and metrics suffer from inaccurately reported volumes of circulating materials in the economy. Hence, this article aims to find a new way to improve and regulate the EoL treatment of recyclable materials and to create value for them. The ultimate goal of the proposed framework is to make original manufacturers responsible for the EoL treatment of their recyclable construction materials and products under the Extended Producers Responsibility (EPR) policy that is enacted in the European Union for sustainable management of waste streams. Adhering to the EPR is difficult for buildings as they are long-term and complex assets. A high degree of transparency, accuracy and security is required to correctly track the lifecycle information of building parts and their respective manufacturers for the EPR implementation. For this purpose, a framework is conceptualised based on the immutability and transparency of blockchain technology to remove trust and trace barriers in the current supply chain. The proposed conceptual model results from the synergy of Building Information Modelling (BIM) technology, material and component banks, blockchain technology and smart contracts for the EoL treatment of recyclable materials. As a result, a data-driven and closed-loop material cycle will be accomplished. This paper demonstrates that through self-executing smart contracts, a clear line of responsibility and ownership could be defined while manufacturers could be made accountable in the post-consumer phase of their construction products. [less ▲]

Performance of lime-metakaolin pastes using gravel wash mud (GWM)

in Cement and Concrete Composites (2020), 114(103772),

The performance of ternary binders using lime, metakaolin (MK) and gravel wash mud (GWM) powders is studied for the development of novel lime-pozzolan pastes. This study examines the influence of varying ... [more ▼]

The performance of ternary binders using lime, metakaolin (MK) and gravel wash mud (GWM) powders is studied for the development of novel lime-pozzolan pastes. This study examines the influence of varying mixture proportions using different types and compositions of lime powders and GWM at different treatment levels on the mechanical properties of lime-MK-GWM pastes. Various characterisation techniques including particle size distribution (PSD), X-ray fluorescence (XRF), X-ray diffraction (XRD), compressive strength tests, simultaneous thermal analysis (STA) and scanning electron microscopy (SEM), were applied on the different raw materials, respectively, on the hardened pastes to determine the reaction kinetics, the resulting microstructure and the mechanical performances of the lime-MK-GWM binder systems. Higher strength-enhancing contributions of thermally treated GWM powders (calcined at 850°C) leading to compressive strengths up to 18 MPa were confirmed and the strength-based evaluations revealed that hydrated lime-based pastes achieved higher mechanical performances than hydraulic lime-based binder systems. [less ▲]

Summertime Overheating Risk Assessment of a Flexible Plug-in Modular Unit in Luxembourg

in Sustainability (2020)

Modular buildings offer faster construction process, provide better construction quality, allow reducing construction waste and are potentially flexible. Frames of modular units can be made of metal ... [more ▼]

Modular buildings offer faster construction process, provide better construction quality, allow reducing construction waste and are potentially flexible. Frames of modular units can be made of metal, timber, concrete or mixed materials but lightweight structures do not always allow erecting high-rise buildings and generally present a higher risk of overheating and/or overcooling. To reconcile these pros and cons, a typology of modular building called Slab was designed by a group of architects. The building is composed on the one hand of a permanent concrete structure named shelf-structure and on the other hand of several flexible removable timber modular units, also known as modules. The shelf-structure will host the common utility rooms and will serve as docking infrastructure for the housing modules. To provide high flexibility, the Slab building was designed to adapt to any orientation and location in Luxembourg. An energy concept and a HVAC systems design has been developed for the Slab building. Furthermore, a two-fold sustainability analysis was carried out. The first part of the analysis regards the determination of the minimum required wall thicknesses of the modules in accordance with Luxembourgish regulatory requirements, although the current regulation does not yet consider the Slab building typology. The second part, which is the subject of this paper, is thermal comfort assessment, more precisely, summertime overheating risk assessment of these modules, in compliance with Luxembourgish standard. In this regard, dynamic thermal simulations have been realized on two module variants; the first fulfills the passive house requirements, and the second—the current requirements for building permit application, which in principle corresponds to low energy house requirements. Simulations showed that with adequate solar shading and reinforced natural ventilation by window opening, overheating risk could be avoided for the normal residential use scenario for both module variants. [less ▲]

Application of the DAD method for damage 1 localisation on an existing bridge structure using 2 close-range UAV photogrammetry

in Engineering Structures (2020)

A novel damage detection and localisation method, the so-called Deformation Area Difference method for localisation of damages in bridge structures is introduced. The method is based on static load ... [more ▼]

A novel damage detection and localisation method, the so-called Deformation Area Difference method for localisation of damages in bridge structures is introduced. The method is based on static load-deflection experiments with the prerequisite of high precise deflection measurement. This study presents the first experiences of applying the DAD method on a real bridge structure. The investigated structure is a prestressed concrete slab bridge with a span of about 27 m, which was built in 2013. The loading on the bridge is applied using six heavy trucks, each weighing up to 32 t. A wide range of the modern measurement technologies were used to achieve high precision measurements of the bridge deflection along the longitudinal axis, namely the photogrammetry using a big size drone, laser scanner, total station, levelling and displacement sensors. The performed load-deflection test was non-destructive since the maximum deformation did not exceed the serviceability limit state. The exercise of the novel damage detection and localisation method on a real structure initiated further optimisation opportunities of the DAD method and the study of its limits. Several boundary conditions and methodical influence factors related to the applicability of the proposed method were analysed, such as impacts of measurement precision, damage degree, the position of damage, and the number of measurement repetitions. [less ▲]

Development of innovative concrete mixtures aggregates

Scientific Conference (2020, June 22)