The depletion of non-renewable natural resources and generation of waste is one of the key issues... more The depletion of non-renewable natural resources and generation of waste is one of the key issues to be addressed to achieve sustainable goals of the modern society. A great amount of natural resources consumption and a significant part of waste production is contributed to the building industry and infrastructure, in particular construction, maintenance and demolition. Moreover, production of building materials (even those with a high recycled content) consumes a lot of energy and produces harmful emissions. Therefore the efficient use of resources implies that the durable building materials and elements produced from such materials should be used as long as possible regardless of the limitation of the building service life. The most challenging building parts are the load-bearing structures because they need to satisfy high quality and strength, structural safety, stability and integrity requirements.
World Conference on Timber Engineering (WCTE 2023)
This study demonstrates the modelling assisted long-term monitoring of wooden bridge components w... more This study demonstrates the modelling assisted long-term monitoring of wooden bridge components with surfaces exposed to solar radiation. An improved multi-phase finite element model is developed to predict the distribution of moisture content, relative humidity and temperature in wood. Hygro-thermal measurements are collected from the monitoring system of the stress-laminated Tapiola Bridge in Finland. The monitoring uses integrated sensors which provide both the relative humidity and the temperature in given locations of the deck, which are compared to the numerical results. The modelling assisted monitoring can help to reduce the maintenance costs of timber bridges, as well as the cost of instrumentation, and to increase the safety.
World Conference on Timber Engineering (WCTE 2023)
The aim of this paper is to present a methodology to predict bending or compression resistance of... more The aim of this paper is to present a methodology to predict bending or compression resistance of structural wooden elements during the onset and growth of the material decay. Two methods are proposed to calculate remaining bending and compression resistance under the attack of brown rot and white rot are presented: (1) reduction of material strength or (2) reduction of the cross-section of the wooden element. The methods are based on the bending and compression tests of material exposed to extreme moisture and are demonstrated as a part of the structural integrity online calculation tool introduced in this paper. They are applicable to planed wood where the decay is expected to progress from the surface inwards. It should be noted that the prediction of structural resistance is in the present state limited to specific loading conditions and decay mechanisms and it is not recommended to replace structural design according to the building codes. However, the estimation of the remaining structural integrity of the material may be very important for the planning of maintenance actions in the structures, such as bridges, where the immediate replacement is not possible or for better safety measures in removing, renovating or demolishing decaying wooden construction.
The paper presents a comparative environmental and economic analysis of several steel structures,... more The paper presents a comparative environmental and economic analysis of several steel structures, starting from an optimal design case considering a new steel structure made with new materials, along with further design possibilities of the same steel building made using reclaimed elements. The analysis is based on a single-storey industrial hall, quantifying the savings achievable by reusing construction materials in a comparative life cycle assessment and life cycle cost assessment. The paper shows the environmental benefits together with the structural feasibility of a strategy based on the reuse approach in construction. The results show that the greatest gain is achieved in the production stage when the reuse approach is adopted rather than recycling. A 29-35% reduction in emissions is observed when the structure is built with reused steel, while the potential financial benefits are greater.
Sidantal 33 Språk finska Nyckelord rivning, cirkulär ekonomi, bygg-och rivningsavfall, materialåt... more Sidantal 33 Språk finska Nyckelord rivning, cirkulär ekonomi, bygg-och rivningsavfall, materialåtervinning, återvinning, återanvändning Referat När det gäller bygg-och rivningsavfall har Finland som mål att senast nästa år (2020) uppnå den materialåtervinningsgrad på 70 procent som fastställts i EU:s avfallsdirektiv. Enligt den senaste uppskattningen från 2017 var återvinningsgraden ca 54 procent. Återvinning av rivningsmaterial hör till de centrala åtgärderna när det gäller cirkulär ekonomi inom byggandet. Sammanlagt 85 procent av bygg-och rivningsavfallet uppkommer i samband med reparationer och rivning av hela byggnader. Därför bör allt större uppmärksamhet fästas vid hanteringen av rivningsprocesserna. Det finns skäl att i högre grad betona rivningens roll som en projekthelhet som föregår bland annat nybyggnadsprojekt. Rivningsinventering är en ny, frivillig åtgärd för kartläggning av material och skadliga ämnen i byggnader som ska rivas. Syftet med inventeringen är att skapa goda förutsättningar för ändamålsenlig återvinning av rivningsmaterial, för undvikande av miljö-och hälsorisker och för en högklassig rivningsprocess i alla slag av rivningsprojekt. Inventering inför rivning bygger på EU-förfarandet Pre-demolition audit. Handledningen ingår i en tredelad serie som ska bidra till högre kvalitet på rivningsprojekt. De två övriga delarna behandlar genomförandet av hela rivningsprocessen samt upphandling av rivning.
Zenodo (CERN European Organization for Nuclear Research), May 22, 2021
Post-consumer wood: waste originating from final wood products whose life cycle ended (i.e. which... more Post-consumer wood: waste originating from final wood products whose life cycle ended (i.e. which are unsuitable for further use, worn out or withdrawn from use) and which were used as final products at least during their first useful life. Wood by-products: waste originating from the wood sector, i.e. from manufacturing where wood and its derivatives are comprehensively processed; wood by-products are generated at the subsequent stages of wood processing into wood materials and final wood products. Recycling: a recovery process in which waste is reprocessed into products, materials or substances used for their original purpose or other purposes; this includes reprocessing of organic material (organic recycling), but excludes energy recovery and reprocessing into materials which will be used as fuels or for filling excavations. Zero waste approach (waste neutrality): When waste production (sources) and-consumption (sinks) are equal, then total net waste is zero. This could be achieved through reuse and recycling. Allocation: partitioning the input or output flows of a process to the product system under study Life cycle assessment (LCA): compilation and evaluation of the inputs, outputs and the potential environmental impacts of a product system throughout its life cycle
Foreword Construction and Demolition Waste (CDW) is by volume the largest waste stream in the Eur... more Foreword Construction and Demolition Waste (CDW) is by volume the largest waste stream in the European Union. Although a vast majority of CDW is recyclable and reusable, one of the common barriers to recycling and reuse of CDW is the lack of confidence in the quality of recovered materials and components. This document extends the Waste Audit Guideline published by the European Commission in 2017 1. The Guideline provides information about the best practices for the assessment of CDW streams prior to demolition or renovation of buildings or infrastructure, called "waste audit". The aim of the Guideline is to facilitate and maximize recovery of materials and components for beneficial reuse and recycling without compromising the safety measures and practices outlined in the EU Construction & Demolition Waste Management Protocol 2. This CDW Management Protocol states that: Any demolition, renovation or construction project needs to be well planned and managed in order to reduce environmental and health impacts while providing important cost benefits. Waste audit (part of pre-demolition audit as defined in the CDW Management Protocol 2) is to be carried out before any renovation or demolition project, for any materials to be reused or recycled, as well as for hazardous waste. Public authorities should decide upon the threshold for pre-demolition audits Pre-demolition audits take full account of local markets for CDW, reused and recycled materials. A good pre-demolition audit must be carried out by a qualified expert (the auditor). The scope of this document includes waste from demolition and renovation works. It excludes construction waste, building equipment and excavated or dredged soils. The guideline has the following target groups of stakeholders: Industry practitioners; construction sector (including renovation companies and demolition contractors), waste treatment, transport and logistics as well as recycling companies, Public authorities at local, regional, national and EU levels,
This work proposes a multi-Fickian method to analyse the hygro-thermal behaviour of timber bridge... more This work proposes a multi-Fickian method to analyse the hygro-thermal behaviour of timber bridge elements under Northern Europe climates. A temperature-dependent wood hysteresis is included in the ...
The structural performance of timber elements may depend on the environmental conditions and in p... more The structural performance of timber elements may depend on the environmental conditions and in particular on the cyclic variations of the moisture content. Moisture gradients in the sections of the structural elements can produce additional stresses, the so-called moisture-induced stresses (MIS), which can cause the formation of cracks and delamination in wooden components. In order to achieve a reliable evaluation of the safety level of timber structures, the present paper proposes a numerical methodology to evaluate the MIS in glulam beams of timber bridges under Northern European climates and mechanical loads. A hygro-thermal multi-Fickian model for prediction of moisture content, relative humidity and temperature in wood is sequentially coupled with an orthotropic-viscoelastic-mechanosorptive model for calculation of wood stresses. Both models were developed by some of the authors in Abaqus FEM code in previous works and their coupling is used here to analyse the hygro-thermo-mechanical response of a glulam beam of Vihantasalmi Bridge in Finland under bending loads. Both perpendicular and parallel to grain MIS in a beam section sheltered from rain are evaluated during a 10-year analysis and conclusions on the crack risk related to these stresses are given.
The project aims are to support C&D waste reduction, preserve natural resources and reduce overal... more The project aims are to support C&D waste reduction, preserve natural resources and reduce overall the environmental impacts of buildings by encouraging the re-use of the building components. It is closely related to the national programme promoting resource and material efficiency, Kestävää kasvua materiaalitehokkuudella. The aim of our research project is to contribute to reaching European policy initiatives towards a resource-efficient and low-carbon economy. It strives to create a better understanding of the end-of-life scenarios of building structures and the possible ways in which the environmental, economic and cultural values of their components can be preserved. Our goal was to approach all aspects of sustainability equally as well as all aspects of the major building materials. It is our hope that those with the responsibility for building waste reduction and CO2 governance at all levels will find useful information and inspiration in this publication.
The depletion of non-renewable natural resources and generation of waste is one of the key issues... more The depletion of non-renewable natural resources and generation of waste is one of the key issues to be addressed to achieve sustainable goals of the modern society. A great amount of natural resources consumption and a significant part of waste production is contributed to the building industry and infrastructure, in particular construction, maintenance and demolition. Moreover, production of building materials (even those with a high recycled content) consumes a lot of energy and produces harmful emissions. Therefore the efficient use of resources implies that the durable building materials and elements produced from such materials should be used as long as possible regardless of the limitation of the building service life. The most challenging building parts are the load-bearing structures because they need to satisfy high quality and strength, structural safety, stability and integrity requirements.
World Conference on Timber Engineering (WCTE 2023)
This study demonstrates the modelling assisted long-term monitoring of wooden bridge components w... more This study demonstrates the modelling assisted long-term monitoring of wooden bridge components with surfaces exposed to solar radiation. An improved multi-phase finite element model is developed to predict the distribution of moisture content, relative humidity and temperature in wood. Hygro-thermal measurements are collected from the monitoring system of the stress-laminated Tapiola Bridge in Finland. The monitoring uses integrated sensors which provide both the relative humidity and the temperature in given locations of the deck, which are compared to the numerical results. The modelling assisted monitoring can help to reduce the maintenance costs of timber bridges, as well as the cost of instrumentation, and to increase the safety.
World Conference on Timber Engineering (WCTE 2023)
The aim of this paper is to present a methodology to predict bending or compression resistance of... more The aim of this paper is to present a methodology to predict bending or compression resistance of structural wooden elements during the onset and growth of the material decay. Two methods are proposed to calculate remaining bending and compression resistance under the attack of brown rot and white rot are presented: (1) reduction of material strength or (2) reduction of the cross-section of the wooden element. The methods are based on the bending and compression tests of material exposed to extreme moisture and are demonstrated as a part of the structural integrity online calculation tool introduced in this paper. They are applicable to planed wood where the decay is expected to progress from the surface inwards. It should be noted that the prediction of structural resistance is in the present state limited to specific loading conditions and decay mechanisms and it is not recommended to replace structural design according to the building codes. However, the estimation of the remaining structural integrity of the material may be very important for the planning of maintenance actions in the structures, such as bridges, where the immediate replacement is not possible or for better safety measures in removing, renovating or demolishing decaying wooden construction.
The paper presents a comparative environmental and economic analysis of several steel structures,... more The paper presents a comparative environmental and economic analysis of several steel structures, starting from an optimal design case considering a new steel structure made with new materials, along with further design possibilities of the same steel building made using reclaimed elements. The analysis is based on a single-storey industrial hall, quantifying the savings achievable by reusing construction materials in a comparative life cycle assessment and life cycle cost assessment. The paper shows the environmental benefits together with the structural feasibility of a strategy based on the reuse approach in construction. The results show that the greatest gain is achieved in the production stage when the reuse approach is adopted rather than recycling. A 29-35% reduction in emissions is observed when the structure is built with reused steel, while the potential financial benefits are greater.
Sidantal 33 Språk finska Nyckelord rivning, cirkulär ekonomi, bygg-och rivningsavfall, materialåt... more Sidantal 33 Språk finska Nyckelord rivning, cirkulär ekonomi, bygg-och rivningsavfall, materialåtervinning, återvinning, återanvändning Referat När det gäller bygg-och rivningsavfall har Finland som mål att senast nästa år (2020) uppnå den materialåtervinningsgrad på 70 procent som fastställts i EU:s avfallsdirektiv. Enligt den senaste uppskattningen från 2017 var återvinningsgraden ca 54 procent. Återvinning av rivningsmaterial hör till de centrala åtgärderna när det gäller cirkulär ekonomi inom byggandet. Sammanlagt 85 procent av bygg-och rivningsavfallet uppkommer i samband med reparationer och rivning av hela byggnader. Därför bör allt större uppmärksamhet fästas vid hanteringen av rivningsprocesserna. Det finns skäl att i högre grad betona rivningens roll som en projekthelhet som föregår bland annat nybyggnadsprojekt. Rivningsinventering är en ny, frivillig åtgärd för kartläggning av material och skadliga ämnen i byggnader som ska rivas. Syftet med inventeringen är att skapa goda förutsättningar för ändamålsenlig återvinning av rivningsmaterial, för undvikande av miljö-och hälsorisker och för en högklassig rivningsprocess i alla slag av rivningsprojekt. Inventering inför rivning bygger på EU-förfarandet Pre-demolition audit. Handledningen ingår i en tredelad serie som ska bidra till högre kvalitet på rivningsprojekt. De två övriga delarna behandlar genomförandet av hela rivningsprocessen samt upphandling av rivning.
Zenodo (CERN European Organization for Nuclear Research), May 22, 2021
Post-consumer wood: waste originating from final wood products whose life cycle ended (i.e. which... more Post-consumer wood: waste originating from final wood products whose life cycle ended (i.e. which are unsuitable for further use, worn out or withdrawn from use) and which were used as final products at least during their first useful life. Wood by-products: waste originating from the wood sector, i.e. from manufacturing where wood and its derivatives are comprehensively processed; wood by-products are generated at the subsequent stages of wood processing into wood materials and final wood products. Recycling: a recovery process in which waste is reprocessed into products, materials or substances used for their original purpose or other purposes; this includes reprocessing of organic material (organic recycling), but excludes energy recovery and reprocessing into materials which will be used as fuels or for filling excavations. Zero waste approach (waste neutrality): When waste production (sources) and-consumption (sinks) are equal, then total net waste is zero. This could be achieved through reuse and recycling. Allocation: partitioning the input or output flows of a process to the product system under study Life cycle assessment (LCA): compilation and evaluation of the inputs, outputs and the potential environmental impacts of a product system throughout its life cycle
Foreword Construction and Demolition Waste (CDW) is by volume the largest waste stream in the Eur... more Foreword Construction and Demolition Waste (CDW) is by volume the largest waste stream in the European Union. Although a vast majority of CDW is recyclable and reusable, one of the common barriers to recycling and reuse of CDW is the lack of confidence in the quality of recovered materials and components. This document extends the Waste Audit Guideline published by the European Commission in 2017 1. The Guideline provides information about the best practices for the assessment of CDW streams prior to demolition or renovation of buildings or infrastructure, called "waste audit". The aim of the Guideline is to facilitate and maximize recovery of materials and components for beneficial reuse and recycling without compromising the safety measures and practices outlined in the EU Construction & Demolition Waste Management Protocol 2. This CDW Management Protocol states that: Any demolition, renovation or construction project needs to be well planned and managed in order to reduce environmental and health impacts while providing important cost benefits. Waste audit (part of pre-demolition audit as defined in the CDW Management Protocol 2) is to be carried out before any renovation or demolition project, for any materials to be reused or recycled, as well as for hazardous waste. Public authorities should decide upon the threshold for pre-demolition audits Pre-demolition audits take full account of local markets for CDW, reused and recycled materials. A good pre-demolition audit must be carried out by a qualified expert (the auditor). The scope of this document includes waste from demolition and renovation works. It excludes construction waste, building equipment and excavated or dredged soils. The guideline has the following target groups of stakeholders: Industry practitioners; construction sector (including renovation companies and demolition contractors), waste treatment, transport and logistics as well as recycling companies, Public authorities at local, regional, national and EU levels,
This work proposes a multi-Fickian method to analyse the hygro-thermal behaviour of timber bridge... more This work proposes a multi-Fickian method to analyse the hygro-thermal behaviour of timber bridge elements under Northern Europe climates. A temperature-dependent wood hysteresis is included in the ...
The structural performance of timber elements may depend on the environmental conditions and in p... more The structural performance of timber elements may depend on the environmental conditions and in particular on the cyclic variations of the moisture content. Moisture gradients in the sections of the structural elements can produce additional stresses, the so-called moisture-induced stresses (MIS), which can cause the formation of cracks and delamination in wooden components. In order to achieve a reliable evaluation of the safety level of timber structures, the present paper proposes a numerical methodology to evaluate the MIS in glulam beams of timber bridges under Northern European climates and mechanical loads. A hygro-thermal multi-Fickian model for prediction of moisture content, relative humidity and temperature in wood is sequentially coupled with an orthotropic-viscoelastic-mechanosorptive model for calculation of wood stresses. Both models were developed by some of the authors in Abaqus FEM code in previous works and their coupling is used here to analyse the hygro-thermo-mechanical response of a glulam beam of Vihantasalmi Bridge in Finland under bending loads. Both perpendicular and parallel to grain MIS in a beam section sheltered from rain are evaluated during a 10-year analysis and conclusions on the crack risk related to these stresses are given.
The project aims are to support C&D waste reduction, preserve natural resources and reduce overal... more The project aims are to support C&D waste reduction, preserve natural resources and reduce overall the environmental impacts of buildings by encouraging the re-use of the building components. It is closely related to the national programme promoting resource and material efficiency, Kestävää kasvua materiaalitehokkuudella. The aim of our research project is to contribute to reaching European policy initiatives towards a resource-efficient and low-carbon economy. It strives to create a better understanding of the end-of-life scenarios of building structures and the possible ways in which the environmental, economic and cultural values of their components can be preserved. Our goal was to approach all aspects of sustainability equally as well as all aspects of the major building materials. It is our hope that those with the responsibility for building waste reduction and CO2 governance at all levels will find useful information and inspiration in this publication.
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Reports by Petr Hradil
Papers by Petr Hradil