| 1. |
- Prieto Rábade, Miguel, et al.
(författare)
-
Tillstånd- och konsekvensbaserad livslängdsbedömning av betongkonstruktioner för dricksvatten
- 2023
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- In Sweden, there are many assets for drinking water such as water towers, water treatment plants and pipes. Many of these structures are made of reinforced concrete and were built between 1950 – 1970. The normal design life of these structures is 50 years meaning that they are reaching their intended design lifespan. In addition, these structures face harsh environments that can lead to degradation. All these leads to the need of repair and renovation of these specifics assets. For that purpose, methodologies and tools for performing inspections, assessing the condition and the time to intervention are needed. Nowadays, in general the procedures for condition assessment are based on the judgement and expertise of engineers performing the inspection. In this project a compilation of best practices for performing the condition assessment for drinking water structures has been performed. This assessment should include an ocular inspection of the object, documentation, tests to ensure certain parameters and an overall analysis of the assessment of the object and finally provide a proposal for measures. The measures must be designed so that both the method and the time aspect are specified. In addition, in this project a methodology and a simplified tool has been developed to accommodate the condition assessment of reinforced concrete drinking water infrastructures and the time to intervention after the assessment. The tool also includes the uncertainty analysis of the condition assessment performed.
|
|
| 2. |
- Suchorzewski, Jan, et al.
(författare)
-
Quality assurance for reused concrete building elements
- 2023
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This report describes work performed by RISE within Återhus project funded by the Swedish Innovation Agency Vinnova within Challenges-Driven Innovation program. The project aimed for developing new tools for accelerating the transition to circular construction understood as reusing building parts in new buildings. The key part of that process was identified as quality assurance and tackling the challenges concerning legal regulations, certification processes, determination of material quality by non-destructive and destructive testing, as well as calculation of remaining service-life. The report discussed also the most common deterioration mechanisms affecting service-life based on the pilot cases from the project. The calculation tool included carbonation and chloride ingress as two main mechanisms leading to risk of corrosion. Additionally theoretical relation of environment relative humidity to corrosion rate was embedded in the calculation to give an estimate of the remaining propagation period after corrosion initiation. The calculation tools were applied to estimate the residual service-life of slab elements of four pilot buildings based on empirical data gathered during inventory and condition assessment using both non-destructive methods and laboratory testing. A simple classification of concrete elements was proposed with a clear link to three main factors: remaining calculated service-life, observed cracking and the target environment.
|
|
| 3. |
- Suchorzewski, Jan, et al.
(författare)
-
Reusing of concrete building elements – Assessment and quality assurance for service-life
- 2023
-
Ingår i: Materials Today. - : Elsevier. - 2214-7853.
-
Tidskriftsartikel (refereegranskat)abstract
- Strategic reuse of demounted concrete elements in new buildings may be one of the solutions that will support the transition to circular construction. To ensure wider application of concrete reuse, RISE developed a methodology for the assessment of the structural condition of existing buildings, and the selection of elements suitable for reuse, including guidelines for their disassembly, storage, and installation. However, one of the main obstacles for wide application of concrete reuse is the uncertainty concerning the remaining service-life of concrete elements and evaluation of quality over the future service-life in a new building. This paper describes a methodology for material and structural assessments which combine non-destructive, on-site testing with traditional laboratory tests of samples extracted from the structures. The results are intended to support the decision-making process on reuse and give a technical basis for the design of new buildings. Great consideration is put on various deterioration mechanisms for concrete and steel corrosion affecting structural condition of housing and office buildings. To assess the impact of degradation processes, theoretical models are considered, while the remaining service life is estimated by means of a simplified approach that provides the basis for evaluation of likelihood and severity of consequences entailed by material degradation on the structural performance. The proposed approach was validated on the results from three pilot projects, where real buildings in Stockholm and Uppsala, Sweden, were reused or prepared for reuse to different extent. The analysed buildings had different functions (housing, office, parking) and structures (prefabricated elements and in-situ casted concrete), being representative for Swedish building stock. One of the buildings has been already dissembled and the prefabricated, where prestressed hollow-core slabs have been successfully reused for a new office building construction. Based on these experiences, a simple classification system for quality of concrete elements for reuse was proposed with three main parameters, namely calculation of remaining service-life, extent of cracking and the target exposure class. The proposed system is not complete and must be further validated for various types of elements and structures by wider group of market actors.
|
|
| 4. |
- Tserpes, K., et al.
(författare)
-
A review on failure theories and simulation models for adhesive joints
- 2022
-
Ingår i: The journal of adhesion. - : Bellwether Publishing, Ltd.. - 0021-8464 .- 1563-518X .- 1545-5823. ; 98:12, s. 1855-
-
Tidskriftsartikel (refereegranskat)abstract
- In the framework of the Cost Action CERTBOND (Reliable roadmap for certification of bonded primary structures), a wide group of researchers from 27 European Countries have had the opportunity to work on the topic of certification of bonded joints for primary structural applications from different engineering sectors such as the aerospace, automotive, civil engineering, wind energy and marine sectors. Since virtual testing and optimization are basic tools in the certification process, one of the key objectives of CERTBOND is to critically review some of the available models and failure theories for adhesive joints. The present paper summarizes the outcome of this task. Nine different models/theories are described in detail. Specifically, reviewed are the Classical Analytical Methods, the Process Zone Methods, Linear Elastic Fracture Mechanics (LEFM), the Virtual Crack Closure Technique (VCCT), the Stress Singularity Approach, Finite Fracture Mechanics (FFM), the Cohesive Zone Method (CZM), the Progressive Damage Modeling method and the Probabilistic methods. Also, at the end of the paper, the modeling of temperature effects on adhesive joints have been addressed. For each model/theory, information on the methodology, the required input, the main results, the advantages and disadvantages and the applications are given. © 2021 The Author(s).
|
|
