The use of rubber aggregates derived from discarded rubber tyres in concrete is a pioneering approach to replacing natural aggregate (NA) and promoting sustainable building practices. Recycled aggregate in concrete serves the dual purpose of alleviating the accumulation of discarded rubber tyres on the planet and providing a more sustainable alternative to decreasing natural aggregate. Due to fact that the crumb rubber (CR) decreases the strength when used in concrete, incorporating titanium dioxide (TiO2) as a nanomaterial to counteract the decrease in strength of crumb rubber concrete is a potential solution. Response Surface Methodology was developed to generate sixteen RUNs which contains different mix design by providing two input parameters like TiO2 at 1%, 1.5%, and 2% by cement weight and CR at 10%, 20%, and 30% as substitutions for volume of sand. These mixtures underwent testing for 28 days to evaluate their mechanical, deformation, and durability properties. Moreover, the compressive strength, tensile strength, flexural strength and elastic modulus were recorded by 51.40 MPa, 4.47 MPa, 5.91 MPa, and 40.15 GPa when 1.5% TiO2 and 10% CR were added in rubberised concrete after 28 days respectively. Furthermore, the incorporation of TiO2 led to reduced drying shrinkage and sorptivity in rubberized concrete, especially with increased TiO2 content. The study highlights that TiO2 inclusion refines pore size and densifies the interface between cement matrix and aggregate in hardened rubberized concrete. This transformative effect results in rubberized concrete demonstrating a commendable compressive strength comparable to normal concrete.

Most of Sweden’s concrete dams were built during the 1900’s. Therefore, they are starting to reach the estimated end of their life-cycle; 50-160 years. Some of these concrete dams are used for hydroelectric purposes. Hydroelectric power is one of Sweden’s primary source for electricity, which approximately makes for 45% of our total electric production. Hence, the need for reparation is increasing for further management and maintaining our electricity production in these concrete dams. Concrete dams are linked by expansion joints. These expansion joints help to reduce the stress, during swelling and shrinking, in the concrete caused by temperature variation. Due to the placement of these expansions joint, they become difficult to repair as well as ensuring the success of a reparation.

Inside the expansion joint there are dimbands. The dimbands can be sealed with bitumen to help their water stopping abilities. For every expansion joint that is sealed with bitumen the estimated climate impact is 0,5 to 1,5 kg CO2-e per joint. If the dimbands, inside the expansion joint, or the surrounding concrete gets damaged or breaks the bitumen varnishes downstream. This generates for an increased environmental and climate impact, due to the need for new bitumen and steel to fill and seal the leak and oils being released into the surroundings. Therefore, it is also of interest to reduce the usage of bitumen or remove it completely from these dimbands. To minimize the complexity and reduce the usage of bitumen this thesis will evaluate a reparation method with bentonite pellets. The reparation method consists of a borehole, which is then backfilled, with bentonite pellets. There are two concrete dams in Sweden which have used this method. Therefore, this thesis work also aims to evaluate how this reparation will last, regarding time, against other options and future expectations regarding the replacement of bitumen.

To begin, the bentonite pellets where first evaluated based on their swelling capabilities and moisture absorption. These attributes were tested by new methods, which are partly based on previous standards. These new methods for the material properties also allowed for long-term evaluation. To evaluate how the bentonite pellets would react over time they were placed in a temperature change cabinet. Five days in these cabinets, were assumed to, correspond to the Northern Swedish climate changes that takes place over a year.  The bentonite pellets were then evaluated by the new methods after 1,5 and 3 years. The results, for both swelling and moisture absorption, showed a difference depending on the bentonite type. The pure Na-bentonite moisture absorption has better absorption capabilities over time, compared to chemically produced Na-bentonite. The results from swelling shows that, regardless of bentonite type, they all induce worse swelling capabilities over time. Although, if they begin thawing cycles at a lower water content their swelling capabilities increases due to the bentonite experiencing exsiccation. 

After the first experimental part, and this newly gathered material knowledge, a miniature version of a concrete dams’ expansion joint were built. The background to this was to research how many altitude meters (mVp) the bentonite pellets could withstand before collapse. Vattenfalls engineers built the testrigg, expansion joint, which primarily consisted of steel. A splintered concrete cube, with a predrilled hole in the middle, was then placed in this steel cartridge. The hole was then filled with bentonite pellets. To see the sequence of the material reaction during pressure tests the testrigg had a top of plexiglass. A manometer was then attached to the plexiglass. The manometer, and a consistent flow of water, allowed for the pressure to be monitored and regulated. When the sedimented bentonite pellets collapses the pressure drops. 

Results from the pressure tests show a correlation between the bentonite pellets declared swelling pressure and the externally supplied water pressure. Depending on the inflow the bentonite pellets can withstand a pressure between 5 to 12 meters of water height – where the exact value is given by the time it is allowed to sediment. These values only consider the initial expansion of the material. Further research is required to evaluate how much water pressure the material can withstand over time.

Based on the findings of this study one of the previously repaired concrete dams’ bentonite seal will collapse in due time, since the reparation exceeds 12 meters in height.

Based on the information provided in this thesis it is difficult to decide whether a bentonite seal will be beneficial for the concrete structure. Further research is required to ensure the sustainability of using bentonite inside concrete structures.

In this technology era, sustainable construction practices have become quite imperative. The exploration of alternative materials to reduce the environmental footprint is of paramount importance. This research paper delves into an exhaustive investigation concerning the utilization of recycled coarse aggregates (RCA) and rubber particles (RP) in concrete. It contributes to the growing body of knowledge aimed at fostering sustainable development in the construction industry by reducing waste, promoting recycling, and mitigating the environmental footprint of building materials. The objective of the study is to evaluate the potential benefits and limitations associated with incorporating these materials, thereby providing a sustainable alternative to conventional concrete. In this research, construction and demolition waste were recycled and used as RCA as a fractional switch of natural coarse aggregate (NCA) from 0% to 100%, with an increment of 20% replacement of NCA in concrete. The RP received from discarded tires generated as automobile industry waste were used as a volumetric fractional substitution of sand in concrete from 0% to 20%, with a 5% increment. No pre-treatment for RCA and RP was carried out before their utilization in concrete. A total of 26 mixes, including control concrete without NCA and RP, with a design strength of 40 MPa, were prepared and tested. Concrete mixes were examined for workability, density, mechanical, and durability properties. It was found that the concrete with 60% RCA and 10% RP showed satisfactory results in evaluation with the strength parameters of control concrete, as the compressive strength obtained for this concrete mix is 40.18 MPa, similar to the control mix. The optimization for RCA and RP was conducted using Response Surface Methodology (RSM). The major concern observed was a rise in water absorption with an increase in the percentage replacement of NCA and natural sand by RCA and RP. Findings from the investigation illustrate a promising prospect for the use of RCA and RP in concrete applications, displaying competent mechanical properties and enhanced durability under certain conditions, offering a viable option for environmentally friendly construction practices. However, the research also sheds light on some constraints and challenges, such as the variability in the quality of RCA and the necessity for meticulous quality control to ensure the reliability and consistency of the end product. It is discerned that further refinement in processing techniques and quality assurance measures is pivotal for mainstream adoption of RCA and RP in concrete construction.

A prestressed concrete bridge was built in 1963 with BBRV cables. It has three spans and a total length of 134.8 m. Due to mining activities the bridge was loaded with trucks with a total weight of 90 ton during 2012-2014 and from 2019. Crack development has been monitored manually and from 2020 with strain gauges and LVDTs.

Cracks normally vary between 0.1 to 0.3 mm in width and grow in length with time. In November 2020 some of the strain gauges on the concrete showed alarming growth and the bridge was closed for traffic. Additional strain gauges were installed on vertical reinforcement bars and an assessment was carried out of the fatigue capacity of the bridge. It was found that the new strain gauges did not indicate any growth in strain and that the fatigue capacity was sufficient. The bridge could be opened again for traffic after being closed for five weeks. Monitoring drift in the strain gauges and fatigue are discussed.

The backbone of European infrastructure was built after the end of the second World War and has reached, or is near to, the end of its nominal design life. This issue urges the development of structural assessment procedures that can provide infrastructure managers the information to make decisions for repairing, upgrading, or replacement. In this paper, a methodology based on load testing and Structural Health Monitoring (SHM) for the assessment of a 65- year-old prestressed concrete bridge located in Northern Sweden is presented. The retrieved data is used to develop and calibrate structural models with different levels of data completeness. The SHM procedure includes the evaluation of material properties by diagnostics, definition of the layout and installation of the instrumentation, test execution, and data analysis. A preliminary structural model is developed based only on the original design parameters, and it is sequentially updated with monitoring data retrieved during a performed proof loading test of the bridge.

The reduction of the structural capacity and eventual collapse of existing concrete bridges is often related to the loss of the initial prestressing forces. This loss can be associated to immediate or time dependent factors such as elastic shortening, creep, relaxation, loading, and cracking, among others. In addition, environmental factors can lead to corrosion of the strands with the subsequent reduction of their area, loss of bond with the concrete and additional cracking which in turn will influence the value of the residual prestress force and the bridge capacity. Therefore, the evaluation of such losses is critical in the decision-making process of defining a financial and environmental cost optimized intervention strategies (e.g., strengthening or replacement). In this paper, a detailed literature review regarding destructive and non-destructive methods for measuring the residual force in prestressed concrete bridges is carried out and used to develop a database of existing experimental tests.

Over the last decades, economic growth and sustained development have enforced the need to ensure reliable and long-lasting infrastructure network to guarantee serviceability and safety. Nevertheless, detrimental effects can lead over time to insufficient structural performance under increasing service loadings and extreme events. Hence, Structural Health Monitoring (SHM) arises as a solution to cope with the need of having timely and continuous data to assess the state of crucial structural assets, such as prestressed concrete bridges. On this matter, the validation of the retrieved data becomes essential for the risk-based decision making in the assessment of bridges, where selecting the most suitable monitoring system could allow to addressed main causes to the right phenomena of deterioration during the service life of the bridge. Consistently with these efforts, this paper deals with a comparative study between the data acquired by different strain-based sensors such as Fiber optic systems (FOS) and strain gauges that were installed to monitor a proof loading test developed on a 65-year-old balanced cantilever prestressed concrete bridge located in Northern Sweden. The monitored data led to establish main differences between emerging types of monitoring systems such as FOS to the well-based strain gauges when exposed to low temperature conditions. Conclusions regarding the influencing parameters between both retrieved data are drawn when evaluating the structural response under serviceability loading conditions is performed, supporting decision makers when different levels of structural assessment are required.

The transport infrastructure consists of roads, bridges, and tunnel networks. Among these, bridges, viaducts, and tunnels are particularly vulnerable due to structural degrad-ation caused by environmental conditions, overloading, and other factors. Ensuring the safety of these assets, especially at the network level, is a significant challenge. The emergence of Bridge Management Systems (BMS) addresses the need for comprehensive information in managing inspections, condition assessments, and optimizing investments in bridge maintenance. Despite the benefits, many countries face challenges in identifying high-risk bridges. Issues include the lack of high-quality data, mixed ownership of assets, diverse management system platforms, varying condition rating schemes, and the absence of a risk-based assessment. This review aims to highlight current practices and research efforts in evaluating bridge condition indices/ratings (BCI) for existing bridges. The identified knowledge gaps emphasize the need for national authorities to develop policies leading to a unified and functional approach for condition rating.

The direct socio-economic consequences of the deterioration of aging infrastructure systems have triggered a continuous process of revising and updating current design standards and guidelines for critical network components. Specifically, long-term degradation processes demand the analysis and evaluation of vital structural assets such as prestressed concrete bridges. It is crucial to develop theoretically consistent, user-friendly, and non-destructive methodologies that engineering professionals can employ to prevent and mitigate potential catastrophic outcomes during the service life of these bridges. This study provides a thorough review of the available testing methods employed over the years for prestressed concrete bridges and introduces a comprehensive framework for evaluating existing methods for residual prestress force assessment. Through a multi-criteria selection process, the three most feasible tests were designed and carried out on an existing 66-year-old balanced cantilever box girder bridge exposed to freezing temperatures that affected the instrumentation plan and test execution. Finally, predictive models compliant with standard codes were calibrated based on the experimental results and the life cycle loss of prestress forces was evaluated to assess relevant bounding intervals. Findings reveal limited on-site testing and discrepancies between calculated residual forces and predictions by standard codes. The saw cut method showed a 18% difference from the initial applied prestress according to the prestress protocol, suggesting the use of a cover meter and concrete modulus evaluation for improved accuracy. The strand cutting method resulted in a 14% difference, emphasizing the need for stress redistribution assessment. The second-order deflection method showed a 6% difference, indicating a focus on enhanced boundary conditions and thorough sensitivity analysis for future investigations.

The process for assessing the condition of a composite bridge via strain measurements is detailed in this thesis. Field measurements were utilized to conduct the assessment of a bridge located in the northern region of Sweden. The bridge is constructed with a trough and two beams, and its structure is supported by two retaining walls that enclose a 21.8-meter-long compartment. A one hundred and sixty kilo Newton vehicle cargo of trains passes the bridge. The objective is to measure and assess the bridge in the event that the axial load increases to 300 kN. Testing commenced in February of 2023. The measurement of strain was conducted using test cases. To determine the bridge's behaviour, modelling was conducted in accordance with the measurements.

For this thesis, a set of models with finite elements was established and analysed. Models are made using data taken in the field and the properties of the materials. With these models as guides, he was able to make a model that is 97% accurate of how the bridge really is. The retaining walls were left out of the models because measurements showed that they were very rigid.  The influence line was also created to find the positions of the axial loads, resulting in the largest value of bending moment. After that, those positions were used for a new model with 350 KN of axial loads. Next, the stresses resulting from the actual axial loads are computed and validated using Eurocode criteria. The last step was to compare the results of the calculation with the results of the finite element analysis.

The modelling results showed values that were similar to the test results, so these were used to compare the results. The modelling results serve by measuring strain interactions d as an evaluation of the bridge's condition. The assessment shows that the bridge is stronger than when standard methods are used.

Within the EU's railway research program IN2TRACK3, a product known as the 3MB track system (Moulded Multi Modular Block slab track system) has been developed. The new innovative track system can be explained as a hybrid solution between traditional ballast tracks and slab track systems. The project has a primary objective for the 3MB system to reduce life cycle costs, improve reliability and punctuality, and increase capacity. The modular construction system allows for easier maintenance of railway tracks, as damaged parts can be replaced more quickly.

In September 2022, a full-scale test was initiated on a 50-meter stretch in Gransjö, north of Boden, situated along the Iron Ore Line (Malmbana). Initially planned for a 2-year testing period, but the track system was dismantled and removed after approximately one year due to the emergence of a recurring severe crack pattern within the blocks.

This degree project aims to conduct a thorough damage investigation, focusing on investigation the reasons behind the repeated crack patterns observed in the 3MB system. The analysis will particularly emphasise the design of the reinforcement and assesses whether the chosen concrete type is suitable for the specific conditions of the construction.

Various laboratory tests, including compressive strength, tensile strength, and thin section analysis, are employed in this investigation. Additionally, a comprehensive literature study is conducted to ensure its credibility and quality.

The results reveal that the aggregate in the sample is porous. This porosity increases the risk of frost damage and cracking in the concrete. The air content was measured at 7.1%, which is somewhat high, together with a high w/c equivalent between 0.50 and 0.55, which has a potentially negative impact on the strength.

The study's in-depth analysis of the 3MB system blocks revealed two main problems: the choice of porous limestone as aggregate and insufficient coverage of the reinforcing steel. The porous nature of limestone led to water absorption and frost susceptibility, while inadequate coverage resulted in corrosion and frost cracking. Laboratory experiments also showed low tensile strength and uneven concrete quality. Calculations indicated the need for spalling reinforcement. Workmanship errors, including haphazard concrete pouring and suboptimal rail fastening solutions, exacerbated the situation. The study highlights the need for improvements in the concrete's waterproofing and fatigue strength to meet the system's requirements and avoid similar problems in the future. Despite the challenges, the project presents potential for success with the right adjustments and lessons learned from the initial testing phase.

Despite challenges and identified obstacles in the project, the 3MB system can succeed. By fine-tuning the concrete recipe, and optimizing reinforcement and aggregate quality, the problems can be avoided. It is crucial to look beyond these obstacles and stick to the overall goal of the project: to establish the sustainable and efficient railways of the future. These challenges can be overcome through careful measures and ensure the project's positive contribution to the transport sector.

The problem of water scarcity can be noticed clearly in the lined canals which provide the irrigation networks. Using porous structures like gabion weirs contributes as a part solution to this problem. In the current study, a laboratory flume was used to calculate the water depths upstream and downstream of the stepped gabion weir that is to be put inside it at a certain distance, and this flume comes with dimensions of 10 m long by 0.30 m wide and 0.50 m height. While the tested hydraulic model of the weir was built with dimensions of 0.30 m width by 0.40 m maximum height, and five lengths with different total distance of 0.88, 0.96, 1.08, 1.12, and 1.20 m respectively. The used gravel samples to fill the gabions were of monosize query gravel with diameters ranging between 0.0095-0.0140, 0.0140-0.0190, 0.0190-0.0250, 0.0250-0.0375, and 0.0375-0.0500 m in a respective way. While the values of discharge, measured during the experiments were in the range of 0.0007-0.0150 m3/s, and a total of 175 trial tests. This study achieved that the detention depth value decreases by increasing the diameter of the gravel sample used, but there is no effect of the gravel sample on the value of release depth, the different illustrated formulas for the detention and release depths maybe can be used usefully for design and scheduling actions in the field where it gave a reasonable matching between the measured and the calculated values of the studied depths, and finally, the errors percentage in an average value for both detention and release tested values were 5.278% and -0.265% respectively

Productivity in the construction industry has been criticized because the industry for a long time has had poorer productivity development compared to other industries, for example the manufacturing industry, but the Swedish construction industry has great opportunities to improve its productivity.

The purpose of this study is to contribute to an increased understanding concerning productivity, measuring of productivity and factors which influence productivity, that in the long run can help companies in the construction industry to improve productivity. Furthermore, various factors that have an impact on productivity were studied, which were investigated in order to see if those factors can be used to increase productivity in construction production.

A qualitative interview study has been conducted in a construction company. The empirical material collected is from introductory interviews and in-depth interviews which have then been compared with a literature study in order to then be able to draw conclusions.

The results show that no particular productivity measurement is performed in all projects, but productivity is checked through regular comparisons against cost calculations and schedules. This study has also shown that planning is one of the most important factors affecting productivity. The lack of management, communication, inappropriate weather conditions, the availability of materials, lack of documents and changes in blueprints can be potential reasons for the reported decline in productivity growth in various ways. Further research on this topic is needed to better understand the different methods that measure productivity and how the factors that affect productivity can be used to increase productivity in the Swedish construction industry.

One of the widespread issues in concrete structures is cracks occurring at early age. Cracks that appear in the young concrete may cause early start of corrosion of rebars or early penetration of harmful liquids or gases into the concrete body. These situations could result in reduced service life and in significantly increased maintenance cost of structures. Therefore it is important for construction companies to avoid these cracks.Volumetric deformations in early age concrete are caused by changes in temperature and/or the moisture state. If such movements are restrained, stresses will occur. If the tensile stresses are high enough, there will be a damage failure in tension and visible cracks arise. These stresses are always resulting from a self-balancing of forces, either within the young concrete bodyalone, i.e. without structural joints to other structures, or from the young concrete in combination with adjacent structures through structural joints.The decisive situation within a young concrete body alone is typically high stresses at the surface when the temperature is near the peak temperature within the body. This situation occur rather early for ordinary structures, say within a few days after casting for structures up to about some meters thickness, but for very massive structures like large concrete dams, it might take months and even years to reach the maximum tensile stresses at the surface. Usually this type of cracks is denoted "surface cracks", and in some cases only a temperature calculation may give a good perception to make decisions of the risk of surface cracking.On the other hand, the decisive situation within a young concrete body connected to adjacent structures, might include both risk of surface cracking at some distance away from the structural joint and risk of through cracking starting in the neighborhood of the structural joint. If the young concrete body is small in accordance to the adjacent structure, or, in other words, if thereis an overall high restraint situation in the young concrete, the risk of early surface cracking might be out of question. So, restraint from adjacent structures represents one of the main sources of thermal and shrinkage stresses in a young concrete body.This study is mainly concentrated on establishing the restraint inside the young concrete body counteracted by adjacent structures, and how to estimate the risk of through cracking based on such restraint distributions. The restraint values in the young concrete are calculated with use of the finite element method, FEM. Any spatial structure may be analyzed with respect to the level of restraint. Calculations of risk of cracking are demonstrated with use of existing compensation plane methods, and a novel method denoted equivalent restraint method, ERM, is developed for the use of restraint curves. ERM enables the use of both heating ofthe adjacent structure and/or cooling of the young concrete, which are the most common measures used on site to reduce the risk of early cracking.In a design situation many parameters are to be considered, like type of cement, different concrete mixes, temperature in the fresh concrete, surrounding temperatures, temperature in the adjacent structure, measures on site (heating/cooling/insulation), sequence order of casting.Therefore, in general a lot of estimations concerning risks of cracking are to be performed. The main objective with the present study is to develop methods speeding up and shorten the design process.Furthermore, established restraint curves have been applied to the method of artificial neural networks (ANN) to model restraint in the slab, wall, and roof for the typical structure Tunnel. It has been shown that ANN is capable of modeling the restraint with good accuracy. The usage of the neural network has been demonstrated to give a clear picture of the relative importance of the input parameters. Further, results from the neural network can be represented by a series of basic weight and response functions, which enables that the restraint curves easily can be made available to any engineer without use of complicated software.A new casting technique is proposed to reduce restraint in the newly cast concrete with a new arrangement of the structural joint to the existing old concrete. The proposed technique is valid for the typical structure wall-on-slab using one structural joint. This casting method means that the lower part of the wall is cast together with the slab, and that part is called a kicker. It hasbeen proven by the beam theory and demonstrated by numerical calculations that there is a clear reduction in the restraint from the slab to the wall using kickers.Restraint is affected by casting sequence as well as boundary conditions and joint position between old and new concrete elements. This study discusses the influence of different possible casting sequences for the typical structure wall-on-slab and slab-on-ground. The aim is to identify the sequence with the lowest restraint to reduce the risk of cracking.

Existing restraint curves have been applied to the method of artificial neural networks (ANN) to model restraint in the wall for the typical structure wall-on-slab. It has been proven that ANN is capable of modeling the restraint with good accuracy. The usage of the neural network has been demonstrated to give a clear picture of the relative importance of the input parameters. Further, it is shown that the results from the neural network can be represented by a series of basic weight and response functions. Thus, the results can easily be made available to any engineer without use of complicated software.

One of the widespread issues in concrete structures is cracks occurring at early age. Cracks that appear in the young concrete may cause early start of corrosion of rebars or early penetration of harmful liquids or gases into the concrete body. These situations could result in reduced service life and in significantly increased maintenance cost of structures. Therefore it is important for construction companies to avoid these cracks. Restraint represents one of the main sources of thermal and shrinkage stresses at early age concrete. Paper I, deals with both the compensation plane method, CPM, and local restraint method, LRM, as alternative methods studying crack risks for early age concrete. It is shown that CPM can be used both for cooling and heating, but basic LRM cannot be applied to heating. This paper presents an improved equivalent restraint method, ERM, which easily can be applied both for usage of heating and cooling for general structures. Restraint curves are given for two different infrastructures, one founded on frictional materials and another on rock. Such curves might be directly applied in design using LRM and ERM.In Paper II, existing restraint curves have been applied to the method of artificial neural networks (ANN) to model restraint in the wall for the typical structure wall-on-slab. It has been proven that ANN is capable of modeling the restraint with good accuracy. The usage of the neural network has been demonstrated to give a clear picture of the relative importance of the input parameters. Further, it is shown that the results from the neural network can be represented by a series of basic weight and response functions. Thus, the results can easily be made available to any engineer without use of complicated software.Paper III, discusses the influence of five casting sequences for the typical structure slab-on-ground. The aim is to map restraints from adjacent structures for a number of possible casting sequences, and to identify the sequence with the lowest restraint. The paper covers both continuous and jumped casting sequences, which include one, two and three contact edges. The result shows that the best casting sequence is the continuous technique with one contact edge.

One of the widespread issues in concrete structures is cracks occurring at early age. Cracks that appear in the young concrete may cause early start of corrosion of rebars or early penetration of harmful liquids or gases into the concrete body. These situations could result in reduced service life and in significantly increased maintenance cost of structures. Therefore it is important for construction companies to avoid these cracks. Restraint represents one of the main sources of thermal and shrinkage stresses at early age concrete. The casting sequence is affected by the restraint from adjacent structures. The present study discusses the influence of five casting sequences for the typical structure slab-on-ground. The aim is to map restraints for a number of possible casting sequences, and to identify the sequence with the lowest restraint. The study covers both continuous and jumped casting sequences, which include one, two and three contact edges. The result shows that the best casting sequence is the continuous technique with one contact edge.

Restrained movement in early age concrete may cause cracking. The boundary conditions – restraint – influence the possible crack distribution. This study aims at highlighting the effect of such restraint on the crack distribution. This is done by using the “Cracking Model for Concrete” in ABAQUS/Explicit simulating the non-linear behaviour under and after cracking. In the study the typical case wall-on-slab was in focus using a structure previously been tested in laboratory with both fixed and free bottom slab. The result of the modelling shows fairly good agreement with the cracks observed in the tests.

Estimation of restraint is very important for accurately predicting the risk of early thermal and shrinkage cracking in concrete structures. The stress in young concrete is affected by changes in its dimensions during hydration and the restraint imposed by adjoining structures. In concrete culverts, the restraints from existing structures acting upon the first and second casting sections to be cast are different, causing them to exhibit different early cracking behaviour. This work presents a new method for predicting restraint in complex concrete structures using artificial neural networks (ANNs). Finite element calculations were performed to predict restraint in 108 slabs, 324 walls and 972 roofs from second sections of concrete culverts, and the results obtained were used to train and validate ANN models. The ANN models were then used to study the effects of varying selected parameters (the thickness and width of the roof and slab, the thickness and height of the walls, and the length of the culvert section) on the predicted restraint. Mathematical expressions for predicting restraint values in slabs, walls and roofs were derived based on the ANN models’ output and implemented in an Excel spreadsheet that provides a simple way of predicting restraint in practical applications. Restraint values predicted in this way agree well with the results of finite-element calculations

Volumetric changes in early age concrete that are restrained might lead to cracks. The degree of restraint is influenced by the casting sequence and the dimensions of the castings. In the current study a new casting technique is proposed to reduce restraint in the newly cast concrete with a new arrangement of the structural joint to the existing old concrete. The proposed technique is valid for the typical structure wall-on-slab using one structural joint. This casting method means that lower part of the wall is cast together with the slab, and that part is called a kicker. Hereby, the behavior of the structure changes from a typical case wall-on-slab to a typical case wall-on-wall. It has been proven by the beam theory and demonstrated by numerical calculations that there is a clear reduction in the restraint from the slab to the wall using kickers. In the paper different kicker heights are studied with the aim of determining the minimum restraint in the upper part of the wall cast in contact with the kicker. The technique using kickers is compared with common measures used in the field to avoid cracking, such as cooling pipes in the new casting and/or heating cables in the adjoining old concrete. The presented method is both cost and time effective, as it opens the possibility to use larger structural length of each casting sequence.

Estimation of restraint is very important for accurate prediction of the risk of concrete cracking at early age. The present study predicts the restraint in 324 walls and 972 roofs for a concrete culvert. A parametric study included the thickness and width of the roofs, thickness and height of the walls, thickness and width of the slab, and length of the structures. Each parameter increased or decreased the restraint in the walls and the roofs. The calculation of the restraint was done elastically by the finite-element method (FE). The results were used by an artificial neural network (ANN) tool, where firstly an influential percentage was investigated as input parameters on the restraint prediction. Equations have been derived by the ANN model to calculate the restraint in the walls and the roofs. It was then used in an Excel sheet to calculate the restraint and compare the result with the result from the finite-element calculations giving high accuracy between the ANN model and the FE calculations

The present study deals with both the compensation plane method, CPM, and local restraint method, LRM, as alternative methods studying crack risks for early age concrete. It is shown that CPM can be used both for cooling and heating, but basic LRM cannot be applied to heating. This paper presents an improved equivalent restraint method, ERM, which easily can be applied both for usage of heating and cooling for general structures. Restraint curves are given for two different infrastructures, one founded on frictional materials and another on rock. Such curves might be directly applied in design using LRM and ERM.

Existing restraint curves have been applied to the method of artificial neural networks (ANN) to model restraint in the wall for the typical structure wall-on-slab. It has been proven that ANN is capable of modeling the restraint with good accuracy. The usage of the neural network has been demonstrated to give a clear picture of the relative importance of the input parameters. Further, it is shown that the results from the neural network can be represented by a series of basic weight and response functions. Thus, the results can easily be made available to any engineer without use of complicated software.

The main objective is to simulate the representation of rubber concrete with different percentages (0, 20, 40, 60, 80, 100%) of rubber using a finite element approach with ANSYS V.15 software to evaluate the behavior of concrete under the influence of mechanical force by using a standard cylinder to calculate its compressive strength, elasticity modulus and displacements for comparison with the previous experimental study, which showed a very close agreement of 5 to 12% when compared between them. The results showed that when the percentage of rubber increases, it leads to a decrease in the compressive strength, that is, its resistance, and an increase in the corresponding displacements and deformations that occur in them, as a result of the concentration of these stresses in the rubber limits. The results also showed that the meshing distribution of the analyzed elements by the ANSYS gave higher values of compressive strength and a decrease in the corresponding displacements when they were regular i.e. homogeneous compared to the irregular ones. Finally, through statistical analysis, it was found that the mean and arithmetic mean were acceptable and close when comparing the theoretical and practical results.

Reinforced concrete (RC) walls have been widely used in different types of civil engineering projects. Therefore, their behaviour under several kinds of loading is of utmost importance. In this study, the main objective is to investigate the behaviour of RC Vierendeel walls under the applied loads by employing numerical analyses for the studied walls. Several assumptions are adopted in these analyses to simulate the actual behaviour of Vierendeel walls, which were experimentally studied in previous investigations. The numerical results showed that the simulated numerical behaviour has a very good agreement with the experimental results of the tested models. Statically, this agreement is validated and verified in terms of the mean and standard deviation values. Therefore, the proposed numerical models and assumptions are the suitable ones to simulate the structural behaviour of these walls under the applied conditions. The structural behaviour is presented in terms of load capacity, crack pattern, deflection, and mode of failure. The results show that the reactive powder concrete (RPC) models have more resistance under the applied load in terms of deflection, cracks, and ductility index than the models of normal strength concrete (NSC). Also, the openings are the main reason for the diagonal cracking at the corners of the RC walls. The deflection in all models is a single curvature. The mode of failure for all models is shear.  

The addition of polymer to a base binder has been documented as a successful approach in terms of improving physical and rheological properties of the base bitumen. However, the main drawbacks of polymer-modified bitumen are incompatibility and degradation of polymer due to aging. This article aims to introduce a bibliometric analysis and review on modifying bitumen with polymers. Additionally, this article intent to highlight the significant gaps and recommendations for future work. Furthermore, another objective of this article is to provide a worth attempt regrading reducing the negative impact of polymer’s drawbacks on the performance of polymer-modified base binder. The findings of this article demonstrated that the test of storage stability for polymer-amended bitumen should be modified, in which the softening point of aluminum tube centerpiece should be measured to introduce a better evaluation for the storage stability of polymer-amended bitumen. In addition, the effects of kinetic factors (mixing sequence, viscosity of blend, shear rate, and time of mixing) on the compatibility of polymer-amended bitumen should be investigated. Moreover, the addition of compatibilizers and stabilizers to polymer-modified binder is recommended to improve compatibility and reduce the effect of aging on degradation of polymer.

Foundation is considered as one of the main parts of any structure such as buildings, railways, bridges, etc. The type of foundation used is highly dependent on the type and properties of soil. The design of foundations requires many factors that should be defined such as the load that the foundation is going to hold, geological conditions of the soil under the foundation, type of soil and the local building code criteria.There are number of differences in the geological and soil conditions in Iraq. As a consequence, these differences are reflected on the type of foundation to be used. Despite these differences, same materials and style of buildings are used all over Iraq. The main problems of Iraqi soil are high gypsum content, salinity and shallow water table depth. These factors that influence the foundations are the soil properties and the amount of loads that transmitted by the superstructure.The situation had been analysed through a case study which illustrated the link between soil and foundation types in three different parts of Iraq (Mosul, Baghdad and Basra). One building was analysed using STAAD. Pro software in these regions. It is evident that Iraqi designers and engineers require local code to define all the loads, materials and design of the foundation to be used. The use of local materials might be very effective from both engineering and economic perspectives.

Objectives: In contemporary urban environments, the intersection between Vulnerable Road Users, specifically unprotected pedestrians, and motor vehicles poses a persistent challenge to road safety. Reversing accidents, characterized by vehicles moving backward, often result in severe consequences for pedestrians due to limited visibility and inherent blind spots for the driver. This paper aims to provide a thorough examination of reversing accidents involving pedestrians in Sweden between 2000–2021; shedding light on the magnitude of the problem, contributing factors, consequences, and potential mitigation strategies.

Method: Using a national database, reversing accidents were compiled by classifying free text descriptions of traffic accidents reported to the Swedish Traffic Accident Data Acquisition. The database was then used to describe reversing accidents and their consequences for struck pedestrians using descriptive epidemiology and cluster analysis.

Results: The results show that reversing accidents accounted for 12% of all pedestrians injured in a collision with a motor vehicle in Sweden during the studied period. In terms of personal characteristics, the struck pedestrians were more often female and of old or young age, whilst the drivers of the reversing vehicles were more often between 18–54 years and men. Most accidents were non-fatal, with only roughly 2% resulting in fatalities. Through a cluster analysis, four distinct accident types were identified. Two of these were identified as particularly important to prioritize in future preventative work: accidents that are characterized by occur during daylight hours in the urban environment (often low speeds) and often result in fatality or serious injury.

Conclusions: Due to the low speeds, reversing accidents are rarely fatal. However, they account for a large proportion of accidents with pedestrians and can be grouped into clearly distinguishable accident types that can function as templates in road safety development in Sweden.

The extant body of literature articulates a noticeable disparity in the susceptibility to cracking and concomitant material degradation between alkali-activated composites (AAC) and ordinary Portland cement (OPC), predominantly attributable to shrinkage and subsequent drying phenomena. This divergence derives from the nanoscopic porosity of AAC binders, which is substantially finer than their OPC counterparts. However, experimental research validates that the judicious incorporation of alternative cementitious materials and fibrous reinforcements enriches the shrinkage characteristics of AAC, thereby enhancing its overall structural performance. Given the crucial role of shrinkage in defining the material integrity of AAC, especially under constrained environmental conditions, an in-depth understanding of shrinkage mechanisms materializes as a necessity for conceiving efficient shrinkage-mitigating strategies. In light of the growing interest in optimizing AAC through various material integrations and methodological innovations aimed at shrinkage diminution, this scholarly review undertakes an extensive synthesis of the laboratorial investigations focused on AAC shrinkage behavior and mitigation. However, this article critically evaluates widespread strategies for shrinkage mitigation, explicating their operative mechanisms. Moreover, it is outlined gaps in the existing research paradigm, promoting for targeted scholarly endeavors to yield a more clear understanding of shrinkage dynamics and to facilitate the advancement of environmentally sustainable AAC composites. Meanwhile, this study intended to consolidate existing research on developing trends in order to gain a comprehensive understanding of the possible uses of AACs and identify viable strategies for addressing AAC shrinkages. By addressing the challenges related to micro-cracking and shrinkage, the long-term durability of AACs may be improved, leading to increased adoption of these materials as sustainable building options in the construction industry today.

Many different wheel/rail profiles are used in the China high-speed railway, and vehicle operation safety and comfort will decrease if the inappropriate wheel-rail profile pair is used. To solve the problem of estimating the wheel-rail match, many numerical models, including vehicle system dynamic models and wheel-rail rolling contact models, have been established to analyse the wheel-rail dynamic responses. Both methods have less consideration of the flexibility and vibration characteristics of ballastless track, leading to deviations in the calculation of middle and high frequency vibration. This paper proposes a vehicle-flexible track coupling model and compares it with the vehicle dynamic model (vehicle-rigid track model). In the rigid track model, only the track irregularities are considered in the track module; the vibrations and deformations of rails, track slab and the foundation are considered in the flexible track model. Taking Chinese CRH3 series wheel profile S1002CN and rail profile CHN60 as examples and considering different track excitations, the two models are compared. The wheel-rail interaction forces, wheel-rail wear depths, wear volumes and vehicle accelerations are chosen as analysis indices for the comparative study.

The results show that the wheel-rail forces of the flexible track model are larger than the rigid track model in the frequency range from 70 to 120Hz, while they decrease obviously in the frequency range above 150Hz. The differences in wear depths and volumes between the two models exceed 10%. Therefore, the flexible track model should be considered when studying the match properties of different wheel-rail pairs.

Near-surface cracks in railhead that caused by rolling contact fatigue (RCF) is one of a kind rail defects that degrade rail track quality. Dependent on the trail load, the cracks can reach to severe level quickly. From many studies, the crack growth can be summarized as follows: At the first phase, the crack is initiated at the rail surface due to shear stresses created by the interaction between wheel and rail. The crack then propagates at about 30⁰ angle underneath. After a certain period of transition, the cracks starts propagating horizontally, vertically, or branching. If they propagates horizontally, the cracks potentially cause rail spalling. If they propagates vertically, then the cracks become more severe and dangerous.

To overcome such defects, the infrastructure manager remove the top of railhead by performing rail grinding periodically. Prior the grinding, rail tracks need to be inspected to figure out how deep the cracks are by performing non-destructive testing (NDT). Eddy current testing (ECT) is one of the common method to estimate rail surface crack depths. Most of the practices in the industry, ECT estimates only the crack depth, without analyzing any other crack parameters, such as crack angle propagation, crack length, crack area, crack branches, etc. It also has no ability to identify multi-leveled cracks, sub surface cracks, dense cracks etc. Since depth is the only crack parameter that can be provided from ECT, the inspector have no knowledge about how severe the surface crack is. Whereas, information of crack phase, that is known from the crack profile (crack angle, crack depth and crack length) is beneficial to determine whether the crack is in initial or severe level. It also helps to decide the right time for grinding and avoid severe cracks remain long in the rails.

Motivated by the benefit of knowing crack parameters, in this study, phased array ultrasonic transducer (PAUT) was used to inspect rail surface cracks. Generally, ultrasonic testing is used to inspect defect of rails at the far-field of the surface, such as at the body or bottom of the rails. Ultrasonic testing is not used to inspect near-surface cracks since the existence of dead zone at the few mm front of the transducer that is caused by piezoelectric crystal ringing inside the transducer. In this study, by utilizing wedge, phased array technique, and setting the optimum gain at the calibration process could decrease the existence of the dead zone. Thus the surface cracks can be observed clearly from the breaking surface to the deepest tip. At the measurement result, crack profile (propagation angle, depth and length), crack branches and multi-level cracks could be observed well. 

To verify the measurement result, the inspected railheads were sliced into pieces with uniform 0.65-mm thickness. From these pieces, 3D cracks networks were reconstructed. Complete information of crack profiles (angle, depth and length) of all cracks under the inspected surfaces were collected and well presented. From the reconstructed crack images, crack tips, multi-level cracks, and crack branches can be seen. These confirms that the measurement results could be used to observe crack profile well. For a brief description about the results, 3.5 mm crack tip depth and 6 mm crack length were estimated well with 8% and 4% error, respectively. Although the measurement system still have lack of detection for crack path that oriented sharply from the horizontal line parallel to the surface, since the ultrasonic waves could not be reflected back by these paths.

At the end of this study, assessment about the potential of measurement speed of the used system when be applied to the rail field inspection was presented. The study is based on the state of the art available at this topic. The discussion is provided in order to motivate the application of the system to be chosen by the rail inspector to use it for the real rail field inspection. 

Boliden är ett gruv- och smältföretag som producerar bas- och ädelmetaller och har verksamhet i Sverige, Finland, Norge och Irland. Företaget bedriver arbete inom prospektering och har flertalet underjordsgruvor dagbrott, anrikningsverk och smältverk.

En av dessa underjordsgruvor är Renströmsgruvan som ligger några mil utanför Skellefteå. Gruvan består av malmkroppar som bryts med olika metoder. En av dessa malmkroppar är Simon som bryts med igensättningsbrytning och skivpallbrytning med återfyllning. Innan brytningen påbörjades i Simonmalmen genomfördes ett antal förstudier för att hitta en brytningsmetod och en förstärkningsplan som passar malmkroppen och bergmassan.

Skivpallbrytningen i Simonmalmen har pågått sedan 2020 och hittills har arton skivpallar tagits. Området är uppbyggt av tvärgående skivpallar, malm och ventilationsstigar samt fältorter som används som transportsträcka. Hittills har ingen uppföljning och jämförelse mellan studierna och utfallet från brytningen utförts.

Syftet med detta arbete är att utvärdera skivpallområdet, hitta skillnader och likheter mellan det nuvarande stadiet och förstudien. Mer specifikt ska följande delar utvärderas:

• Geometri av malmkroppen
• Bergförhållanden
• Skadezon
• Över- och underberg
• Återfyllning (cementstabiliserat gråberg, CRF)
• Förstärkning
• Kostnad för området (brytning och återfyllning) och produktivitet

Ovanstående punkter har utvärderats då de har en betydande roll för resultatet, produktionen och planeringen av området. Målet med studien är ge rekommendationer för fortsatt drivning för att kunna förbättra brytningen i området.

Synliga skador på bergförstärkningen är låg och de uppkomna skadorna går att anknyta till kontaktytorna mellan bergarterna och bergkvalitén. Dessa bidrar till en oplanerad tunnelprofil och uppsprickning. Mängden överberg är mer än vad som uppskattades i förstudien, vilket troligtvis beror på en sämre bergkvalitet i verkligheten än vad som uppskattades i förstudien. Förstärkningen som rekommenderades i förstudien är förstärkningsplanen som används i dagsläget. Den rekommenderande betongtjockleken för området underskrids, men inga större skador har uppkommit på grund av detta. Återfyllningen som används är gråberg för de sekundära skivpallarna och cementstabiliserat gråberg (CRF) för de primära skivpallarna. CRF:ens hållfasthet påverkas av sprängningen och av gråberget som ligger i botten av återfyllningen (gråbergslimpa). En för låg hållfasthet påverkar mängden fyllinblandning i skivpallarna. I förstudien beräknades det med en konstant driftkostnad för området vilket inte är utfallet, kostnaderna är varierande och beror på hur mycket tillredning som sker i malm och gråberg. Den största skillnaden mellan beräknade kostnader och utfall är kostnaden av CRF:en.

Den främsta rekommendationen för fortsatt drivning är att se över förstärkningen som är i tvärorterna efter pelarna. Detta då rekommenderad betongtjocklek underskrids, men inga stora skador har uppkommit som följd. Då det är kontaktytorna och bergkvalitén som påverkar drivningen mest bör dessa tas i beaktning vid planering av skivpallarna och förstärkning. Man bör undvika att preparera de primära skivpallarna med för mycket gråberg i sulan. Då detta bidrar till en mindre stabil återfyllning som leder till utfall av CRF.

In early 2020, cracks were discovered on the bridge crossing the Torne River at Autio. This resulted in an investigation being launched to determine the structural state of the bridge. In conjunction with this investigation, monitoring equipment was installed on the bridge, which enabled the collection of measured strain at four critical points on the bridge. 

In this thesis the measured strain was used to approximate stresses in the prestressing cables and thereby calculate the effects of fatigue on the bridge. Two different structural standards were used to calculate the results: Eurocode 2, and fib Model Code 2010. Likewise, two different cycle-counting methods were used to calculate the results: the Rainflow-algorithm, and the largest-magnitude approach. 

Regardless of structural standard or cycle-counting method, the results indicate that the effects of fatigue are neither an issue for the bridge, currently, nor will it be in the expected lifetime of the bridge.

Försörjningskedjan i byggprojekt konvergerar materialflödet mot byggarbetsplatsen. Där byggs materialet ihop till en enskild produkt. Materialhanteringen är en av de viktigaste faktorerna för hur byggprojekt presterar gällande kostnad, tid, säkerhet i planeringen och arbetsplatsolyckor. Att flera olika materialflöden hanteras i projektspecifika miljöer av projektspecifika organisationer innebär en komplicerad logistikhantering. Trots det är byggbranschen jämförelsevis dålig på att utnyttja expertis och moderna tekniker för att förbättra materialhanteringen.

Ett effektivt informationsflöde är väsentligt för att kunna upprätthålla ett effektivt materialflöde. Men byggprojekt har många olika källor till information med olika nivåer av detaljrikedom. Det leder till bristande kommunikation vilket får flera negativa effekter.

Tidigare studier (Xue, Wang, Shen & Yu, 2007; Donyavi & Flanagan 2009) har visat att det finns ett behov av digitala verktyg för styrning av försörjningskedjan till byggprojekt. Andra studier (Olsson, 2000; Samuelson & Björk, 2014; Blanco, Mullin, Pandya & Sribdhar, 2017) har visat att det sällan är en helt friktionsfri process att implementera nya rutiner och digitala verktyg i byggbranschen. Därför finns ett behov av att studera hur företag kan lyckas med implementering av digitala verktyg för materialhantering.

Målen med studien är att undersöka framgångsfaktorer för implementering av digitala verktyg för materialhantering i husbyggnadsprojekt och vilka effekter lyckad implementering kan leda till. Syftet är att öka effektiviteten i materialflöden i byggproduktion.

Den här studien har utförts som en flerfallsstudie på flerbostadsprojekt där ett digitalt verktyg för materialhantering använts. Fallstudien består av ett primärt fall och ett jämförande fall. I det primära fallet har en långsiktig implementering av det digitala verktyget misslyckats, till skillnad från i det jämförande fallet. Det digitala verktyget som ingår i fallstudien är Myloc Construction och det används bland annat för att koordinera transporter till byggarbetsplatsen. Fallstudien genomfördes som en intervjustudie. Utöver respondenter från de olika byggprojekten inkluderas även respondenter från utvecklaren av det digitala verktyget.

Det digitala verktyget tillgängliggör information om bland annat leveranser och förflyttningar påbyggarbetsplatsen. Detta förenklar koordineringen av materialflödet på byggarbetsplatsen och på så sätt kan det bidra till ökad samordning, färre störningar, minskad trängsel och effektivare godsmottagning. Dessutom finns ett bokningssystem för lyftresurser vilket gör det enklare att anpassa materialflödet efter resurstillgången eller vice versa. Studien har identifierat tre nyckelfaktorer för implementeringen av digitala verktyg för materialhantering:

• Planering - Förutsättningarna i produktionen måste anpassas efter hur logistiken och det digitala verktyget är tänkt att fungera.
• Resurser – En enhet som driver implementeringen av det digitala verktyget bör ägna sig åt att öka följsamheten och att driva igenom förbättringar i hanteringen av det digitalaverktyget. Hur mycket resurser som krävs för detta beror på logistikuppläggets komplexitet.
• Riktlinjer – Det krävs riktlinjer för hur det digitala verktyget ska hanteras. Dessa bör till stor del anpassas efter projektets förutsättningar. En riktlinje som är viktig oberoende av projektets utformning är att bestämma med vilken framförhållning som information ska matas in. Riktlinjerna kan antingen förmedlas via projektspecifika instruktioner eller via avtal.

Två tidigare studier (Olsson, 2000; Sullivan, Barthorpe och Robbins, 2010) har beskrivit att byggentreprenörer inte är vana vid att lägga resurser på att förbättra logistiken. Den här studien har bekräftat att det till viss del fortfarande är så, men studien tyder också på att detta är något som håller på att bli bättre. Dessutom bekräftar studien att användarna generellt är positivt inställda till att testa ny teknik för att utveckla sitt arbete.

En studie (Aloini, Dulmin, Mininno & Ponticelli, 2012) har visat att sen inblandning av aktörer, brist på samordnad utformning och bristfälligt urval av leverantörer är riskfaktorer för implementering av ett logistikkoncept som kallas Supply Chain Management. Studien som gjorts i detta examensarbete kunde identifiera att dessa riskfaktorer även hindrat implementeringen av det digitala verktyget för materialhantering.

The microscopic analysis of an ice surface is very difficult, due to the nature of the ice. The optically transparent, brittle and very environmentally sensitive surface is hard to analyze in a manner that does not render the results useless from damage or errors in measurements.The ice surface is ill suited for contact microscopy, like Atomic Force Microscopy (AFM) or other methods of sliding a probe over the surface. Furthermore the ice surface is transparent, so even cold room optical microscopy is not feasible. Due to the vacuous atmosphere Scanning Electron Microscope (SEM) is not an option. In this paper the authors look at some casting techniques to try and reproduce the surface with a substance much better suited for optical and mechanical measurements, as well as having a longer shelf life and being easier to handle. Different evaluations have been considered, where the frequency information is used as a measure of resolution, comparing the resolution loss of different casting materials.The casting materials used are different products from the dental industry, as well as polyvinyl formvar, a dissolved polymer that is very useful for casting of ice surfaces.

During the winter season, ice causes major problems in many Swedish railway tunnels. Ice, rock and shotcrete in the roof and on the walls may come loose and fall down, installations and cables can break due to ice loads and the tracks can become covered with ice. To maintain safety and prevent traffic disturbances, many tunnels require frequent maintenance. The removal of ice, loose rock and shotcrete is expensive and potentially risky work for the maintenance workers. To reduce maintenance costs, it is important to improve our knowledge of frost penetration inside tunnels and investigate the effect of ice pressure and frost shattering on loadbearing constructions. The aim of this investigation was to gather information about the problems caused by water leakage and its effect on the degradation of a rock tunnel when subjected to freezing temperatures. There are many factors that determine whether frost or ice formations will appear in tunnels. To collect information on ice formation problems, field observations were undertaken in five of Sweden’s railway tunnels between autumn 2004 and summer 2005. For one of the tunnels, follow-up observations also took place in March during the years 2005, 2006 and 2007.

Bygg- och anläggningsindustrin brottas med frågor kring produktivitetsutveckling, då inte önskad produktivitet alltid uppnås. För att kunna öka och utveckla produktiviteten bör anläggningsföretag kunna mäta och följa upp sina prestationer. Genom att kunna mäta prestationer skapas en förståelse över hur verksamheten går och i vilken riktning den är på väg. Det finns svårigheter med att ta fram ett tydligt arbetssätt kopplat till målarbete inom anläggning då alla projekt har unika förutsättningar att utgå ifrån. Fel inom anläggningsprojekt kan leda till stora ekonomiska konsekvenser för företaget, och utan en tydlig målbild med relevanta prestationsmått är det svårt att veta om arbetet som utförs ligger i linje med de satta målen eller ej. För att kunna bemöta problemen har forskning inom problemområdet föreslagit att det är viktigt att det finns ett linjerat arbetssätt genom hela organisationen, så kallad strategisk linjering. Då företag inom bygg- och anläggningsbranschen länge blivit kritiserade för sin långsamma utveckling är strategisk linjering av prestationsmått ett intressant område att studera. Det är även ett relativt outforskat område när det kommer till andra studier och speciellt fallstudier inom bygg- och anläggningssektorn. Syftet med examensarbetet är att bidra till en ökad kunskap om strategisk linjering av produktionsmål och prestationsmått och dess specifika implementering inom anläggning. Examensarbetet studerar ett konkret implementeringsarbete avseende strategisk linjering av produktionsmål och prestationsmått inom ett anläggningsföretag. Målet med studien är att, med utgångspunkt i litteratur inom ämnesområdet adressera följande två huvudfrågeställningar:

1.     Hur kan ett anläggningsföretag implementera strategisk linjering mellan produktionsmål och prestationsmått?

2.     Vad kan utgöra hinder respektive möjliggörare vid implementering av strategisk linjering av prestationsmått inom anläggning?

Datainsamlingen har bestått av intervjuer, dokumentinsamling och observationer. Innan datainsamlingen påbörjades utfördes en litteraturstudie inom forskningsområdet strategisk linjering av prestationsmått som ligger till grund för den teoretiska referensramen och den framtagna analysmodellen.  

För att möjliggöra implementering av strategisk linjering mellan produktionsmål och prestationsmått krävs en sammanhängande målnedbrytning från ett anläggningsföretags övergripande mål ned till specifika produktionsmål som sedan kan följas upp genom tydliga mätbara prestationsmått. Prestationsmåtten ska vara lätta att förstå och utföra, och vara linjerade med de specifika produktionsmålen som i sin tur är linjerade med anläggningsföretagets övergripande mål. Analysen av litteraturen sammanvägt med fallföretagets förutsättningar visar att det är av värde att ha prestationsmått som både indikerar på vad som sker just nu, och vad som har skett under en viss period för att både kunna vara proaktiva och reaktiva i sitt agerande kopplat mot målarbetet. De prestationsmått som återkommande nämns i litteratur kring strategisk linjering av prestationsmått och som är analyserade i studien för att uppfylla detta är key performance indicators (KPI), performance indicators (PI), result indicators (RI) och key result indicators (KRI). Då projekt inom anläggningsbranschen består av väldigt varierande förutsättningar finns det möjliggörare för att lyckas implementera strategisk linjering av prestationsmått, men det finns även en del hinder.  

Det största hindret med strategisk linjering av prestationsmått som upptäcktes i studien är att lyckas få prestationsmåtten tydligt mätbara då olika aktiviteter i ett anläggningsprojekt mäts i olika enheter. Det har visat sig att vara viktigt att alla som ska använda prestationsmåtten har en förståelse varför de ska användas, och hur de ska användas för att få öka möjligheterna för ett gemensamt arbetssätt inom företaget. Ytterligare ett hinder är om prestationsmåtten tas fram utan anknytning till produktionsmål, kritiska framgångsfaktorer, strategi, övergripande mål och vision, vilket skulle bidra till en avsaknad av enhetlighet inom ett anläggningsföretags målarbete. Det sista hindret som studien visar är om prestationsmåtten används på fel sätt och enbart visar resultat på past performance. Möjliggörarna till strategisk linjering av prestationsmått har visat sig vara att tydligt utformade prestationsmätningar bidrar till ett gemensamt arbetssätt, och det blir enklare att kontinuerligt följa upp resultat över tid. Med tydligt utformade prestationsmått ökar sannolikheten att tidigt upptäcka avvikelser som i sin tur kan korrigeras i rätt tid innan problemet hinner växa sig större. Rekommendationerna till fallstudieföretaget och andra anläggningsföretag blir att tydliggöra hur prestationsmåtten ska mätas, och hur de ska följas under projekten. Nästa steg blir att tydligt sprida prestationsmåtten ut i verksamheten för att säkerställa att alla förstår hur de ska användas vilket kan leda till större möjlighet att styra processen i rätt riktning. 

Denna rapport har på eget initiativ tagits fram av rapportskrivaren och har ett fokus på vad en östlig sträckning av Norrbotniabanan in i Luleå kan innebära.Norrbotniabanan är i full fart med att byggas och börjar sakta men säkert närma sig Luleå.Ännu är det inte bestämt om Norrbotniabanan ska ta sig in i Luleå via en östlig eller västligsträckning. Många viktiga aktörer förespråkar just en östlig sträckning. Rapportens syfte är attsammanställa för- och nackdelar med den östliga sträckningen och dess konsekvenser förLuleå KommunSlutsatsen som rapportskrivaren genom en litteraturstudie och diskussion kommit fram till äratt vid byggnationen av en öppningsbar bro över halmholmen så finns det fler, och viktigare,fördelar än nackdelar. Men vid fallet att möjligheten för en öppningsbar bro bortgår så falleraralla fördelar med en östlig sträckning då det ekonomiska konsekvenserna vid störning avsjöfarten blir för stora. 

EFLA og Luleå Tekniska Universitet har bistått Agder fylkeskommune med forsterkning av to gamle stålbjelkebruer i Agder fylke, som dannet en flaskehals for vegtransport i området. I prosjekteringen er det brukt en metode som aldri har vært brukt i Norge før, og den har vist seg å være effektiv i forhold til kostnad, gjennomførbarhet og miljøpåvirkning. Prosjektet er et eksempel på vellykket nordisk samarbeid, og kan ha overføring til fremtidige prosjekter

Ballast is a critical construction material in railway bridges, as it distributes heavy loads from the rails tothe supporting structure. According to the Eurocode, axle loads should be distributed through the ballastwith a load distribution ratio of 4:1, while Swedish standards recommend a ratio of 2:1. This discrepancybetween the Eurocode and Swedish standards forms the basis of the first research question in this thesis,which aims to determine the impact of this difference on the capacity of railway bridges.With increasing traffic volumes on Malmbanan (the Ore Line from Luleå on the Baltic to Gällivare andKiruna, extending to Narvik on the North Sea), there is a need to raise the allowable axle load on thetrack. Consequently, the capacity of railway bridges must be analyzed and enhanced if necessary. Thepurpose of this study is to analyze the effects of increased axle loads on railway bridges and their fatiguecapacity.Trafikverket considers the issue of increasing railway bridge capacity to be significant and is funding anongoing project at LTU. This project involves conducting fatigue tests on a reinforced concrete troughbridge to gain a better understanding of the fatigue capacity of railway bridges and how ballast transferaxle loads.Hand calculations of the load effects from dead weight and axle loads are performed to evaluate thecapacity of the bridge being tested at LTU. The axle loads analyzed in this study are 25, 30, 32.5, 35, and40 tons. The load effects are examined using Eurocodes, Model Codes issued by the International Fed-eration of Concrete Structures (fib), and Swedish standards to verify the bridge's capacity concerning bothfatigue and ultimate limit states.The calculations for the ultimate limit state reveal no significant difference between the load distributionratios of 4:1 and 2:1. Furthermore, Ultimate Limit State (ULS) calculations indicate that the axle load onMalmbanan can be increased to 35 tons without risking bending or shear failure in railway bridges. Acritical aspect is the assessment of the shear capacity of the slab connection to the longitudinal beam.The fatigue analysis of the longitudinal bending reinforcement suggests that the axle load should notexceed 30 tons according to the proposed revised Eurocode for concrete structures (pR EN 1992-1-1,2020). This conclusion is valid under the condition that the number of trains per day or wagons per trainremains unchanged (currently 28 trains per day, each with 68 wagons). However, the fib Model Code2020 allows a higher load, 40 ton.The shear fatigue of the connection of the slab to the longitudinal beams is less studied and the codes aremore conservative and only allows 1 million load cycles for an axle load of 30 tons.  However, no shearcracks have appeared after 10 million load cycles, so the shear capacity is probably higher. This willhopefully be shown in the further testing of the bridge.