Prefabricated concrete elements are widely used in the construction industry today. With advantages such as time savings, increased safety at the construction site and minimized material usage, prefab becomes a major challenger to the traditional on-site casting construction method. However, constructing a bridge in concrete still presents challenges when using prefab as a construction method. Hence, more research in the area is needed. This master thesis has been studying the behavior of a prefabricated skew angle slab and the connection between the slab and wall elements of a bridge. The study was conducted using a finite element software, where three 3D-models of skew angle slabs were created. The three models had different skew angles (0, 15 and 30 degrees) and crossed the same path. The models could represent both the slab and the slab-wall connection. The finite element analysis showed that slabs with angles up to 15 degrees could be designed as a straight bridge. However, when the skew angle increases to 30 degrees, the behavior of the slab and connection changes significantly. Furthermore, the results show that a stress concentration occurs in the obtuse corner and that the stress increases when the skew angle increases. Moreover, there is a slight uplift in the acute corner when the skew angle increases to 30 degrees.

Ultra-high performance concrete (UHPC) was evaluated as a potential material for future bridge deck designs. Material characterization tests took place to identify potential challenges in mixing, placing, and curing UHPC. Biaxial testing was performed to evaluate behavior of UHPC in combined tension and compression stress states. A UHPC bridge deck was designed to perform similarly to a conventional concrete bridge deck, and a single unit bridge deck section was tested to evaluate the design methods used for untreated UHPC. Material tests identified challenges with placing UHPC. A specified compressive strength was determined for structural design using untreated UHPC, which was identified as a cost-effective alternative to steam treated UHPC. UHPC was tested in biaxial tension-compression stress states. A biaxial test method was developed for UHPC to directly apply tension and compression. The influence of both curing method and fiber orientation were evaluated. The failure envelope developed for untreated UHPC with random fiber orientation was suggested as a conservative estimate for future analysis of UHPC. Digital image correlation was also evaluated as a means to estimate surface strains of UHPC, and recommendations are provided to improve consistency in future tests using DIC methods. A preliminary bridge deck design was completed for untreated UHPC and using established material models. Prestressing steel was used as primary reinforcement in the transverse direction. Preliminary testing was used to evaluate three different placement scenarios, and results showed that fiber settling was a potential placement problem resulting in reduced tensile strength. The UHPC bridge deck was redesigned to incorporate preliminary test results, and two single unit bridge deck sections were tested to evaluate the incorporated design methods for both upside down and right-side up placement techniques. Test results showed that the applied design methods would be conservative for either placement method. / Ph. D.

The diploma thesis deals with design and assessment of the main structure of the road bridge which leads the road I/55 over the highway D1. The thesis contains three designs of the construction. One design was chosen for detail solution. The thesis includes statical analysis, drawing documentation and visualization.

The presented thesis describes the development of an automation design procedure for structural design of concrete slab bridges and how it can be used to conduct a set-based structural design. The automation procedure integrated finite element modelling, analysis and structural related verification (verifications in geometry, ULS and SLS) together and realised automatic implementation of the two processes. By employing the automation design procedure and the set-based design methodology, a case study is performed based on an existed bridge. In contrast with a traditional point-based design process, the set-based structural design considers a wide range of possible design solutions, called design space, which are combinations of possible choices of different design parameters. In the case study, the design parameters like structural dimensions and reinforcement layout are considered and constitutes the design space. The design space is first narrowed by structural related constraints and further narrowed by multiple criteria which are material cost, material mass and global warming impact (equivalent CO2 emission) until reaching an optimal solution considering the three criteria. The results of the case study reveal the potential of set-based design by using the automation design procedure in obtaining optimal design solutions on the three mentioned criteria. Meanwhile, a rough time estimation shows the automatic procedure helps improve the design efficiency. It also suggests that the evaluation and decision of the finally chosen solution should be the trade-offs between material cost and environmental impact.

Diploma thesis is focused on design of road bridge bearing structure over a D1 highway. Structure is continuous slab with 4 fields beared by local supports. It is prestressed in longitudinal direction. Internal forces are calculated in Scia Engineer software. Reference is made according to valid standarts.

A nonlinear finite element analysis was performed for an existing road bridge in order to see if that could show a higher load bearing capacity, as an alternative to repairing or replacing. The regular linear analysis had shown that the bridge could not take any traffic load due to the effects from large and uneven support settlements. It is a five-span reinforced concrete bridge with a continuous slab on supports made out of rows of columns. The width-to-span ratio was around 1 and the supports were angled up to about 30°, giving rise to a complex three-dimensional behaviour, which was seen and studied in the nonlinear results. Since the bending moment was the limiting factor, the nonlinear analysis focused on that. The direct result was that the load bearing capacity was 730 kN for the traffic vehicle boogie load, B, in the ultimate limit state. This was however only for the load case tested, and several more disadvantageous vehicle positions may exist. Other aspects also became limiting, as the maximum allowed vertical deflection in the serviceability limit state was reached at 457 kN. The most restraining though, was the shear capacity from the linear analysis; 78 kN, since it was not possible to simulate that type of failure with the shell elements used in the nonlinear finite element analysis. The main aim of the thesis was nonetheless reached, since the nonlinear analysis was able to show a significant increase in load bearing capacity. A comparison was made with the settlements for the nonlinear case, to see how much influence they had on the load bearing capacity for traffic load. This was performed for both the bridge and a simple two-span beam. Both showed that there was no effect on the load bearing capacity in the ultimate limit. One thing to note was that the full settlements were applied, and with no relaxation due to creep. Another aim of the thesis was to make comments on the practical usability of the nonlinear finite element method in load bearing capacity assessments. A linear analysis was performed before the nonlinear in order to be able to determine the load case to be used in the latter. This worked well, as the strengths of the two methods could then be utilized. Convergence problems were however encountered for the nonlinear when using the regular static solver. Due to this, the dynamic explicit calculation scheme was used instead, treating the case as quasi-static. This managed to produce enough usable results. It was concluded that the nonlinear finite element method is useable for assessment calculations, but that its strengths and weaknesses must be known in order to make it an efficient method.

The diploma thesis deals with the design of the motorway bridge over the II / 464 road between Butovice-Bílovec. For the bridging design four variants were made, from which a variant of the slab with longitudinal extensions was selected for further processing. The design assessment was performed for the ultimate limit state and serviceability limit state according to valid standards. Determination of internal forces was performed on the model developed in Scia Engineer 18.0.

This thesis focuses on design and assessment of load-bearing construction of a bridge over Jevišovka river at road I/53 near Lechovice. The bridge was designed as a trapezoidal cross-section slab. This solution was chosen from three sketch eventualities. The work includes an implementing engineering report, construction process report and report about static-analysis, the attachments include the sketch, vizualization, drawings, component drawing, construction process and the static-analysis of this structure. Computing of internal forces was performed by computational software Scia Engineer 17.

The aim is to propose solutions to the new bridge construction due to its unsatisfactory compared to the existing bridge reconstruction project . There are three studies bridging and selected variant trapezoidal plate further processed static opinion. The design was judged by the ultimate limit states and usability. Partial assessments were made for the anchoring system, anchorage area , unravels notched bars and store design to support .

This diploma thesis targets on diagnostics and assessment of bridge structure Most Kaštanová přes Svitavu, reg. number 380-001. Concrete material characteristics have been assessed in laboratory, after visual inspection, diagnostical testing and sample core drilling were made. Findings from laboratory tests are summarized in the conclusion of the thesis. It focuses on an evaluation of current bridge condition and presents various options that will help polong lifetime of the bridge.