This thesis studies the behaviour of ultra-high-performance concrete (UHPC) in the precast concrete bridge deck connections. The experimental program consisted of shear pocket push-out testing and full-scale bridge deck testing. The main objective was to study the UHPC performance in the shear pocket and joint connections. All specimens were statically loaded until failure. The push-out test specimens consisted of two small 45 MPa concrete slabs on either side of a built-up steel section, joined together by shear studs and UHPC shear pockets. There were three 6-stud specimens, two 3-stud specimens and two 0-stud specimens. The 6-stud specimens reached ultimate loads of 2642 kN, 2892 kN, and 3045 kN. The 3-stud specimens reached ultimate loads of 1445 kN and 1674 kN. The 0-stud specimens reached ultimate loads of 4.91 kN and 3.44 kN. The failure modes for the 6-stud and 3-stud specimens were stud failure or concrete crushing, while the 0-stud specimens failed when the UHPC and steel section surface debonded. The push-out specimens were instrumented with LVDTs, pi-gauges and strain gauges to collect data on the displacements, debonding, and shear stud strains throughout testing. The bridge deck testing included a full panel deck (FPD) and jointed panel deck (JPD). The FPD was cast monolithically with regular strength concrete and had UHPC shear pocket connections to the steel support girders. The JPD was cast as two half-size regular strength panels connected together with a UHPC joint, and connected to the steel support girders with UHPC shear pockets. The FPD and JPD reached ultimate loads of 1926 kN and 1878 kN, respectively. Both decks failed by concrete punching under the load point. The bridge decks were instrumented with LVDTs, pi-gauges, and strain gauges to collect data on the deflections, crack widths, steel strains, concrete strains, and shear stud strains throughout testing. The experimental results implied the number and length of the studs in the shear pockets may be reduced. The better performance of the FPD also indicated the circular pockets were superior and the use of UHPC in precast deck connections does not significantly improve the overall performance.

"The use of modular bridge deck components has the potential to produce higher quality, more durable bridge decks; however, the required connections have often proved lacking, resulting in less than desirable overall system performance. Advanced cementitious composite materials whose mechanical and durability properties far exceed those of conventional concretes present an opportunity to significantly enhance the performance of field-cast connections thus facilitating the wider use of modular bridge deck systems. Ultra-high performance concrete (UHPC) represents a class of such advanced cementitious composite materials. Of particular interest here, UHPCs can exhibit both exceptional bond when cast against previously cast concrete and can significantly shorten the development length of embedded discrete steel reinforcement. These properties allow for a redesign of the modular component connection, facilitating simplified construction and enhanced long-term system performance. This study investigated the structural performance of field-cast UHPC connections for modular bridge deck components. The transverse and longitudinal connection specimens simulated the connections between precast deck panels and the connections between the top flanges of deck-bulb-tee girders, respectively. Testing included both cyclic and static loadings. The results demonstrated that the field-cast UHPC connection facilitates the construction of an emulative bridge deck system whose behaviors should meet or exceed those of a conventional cast-in-place bridge deck"--Technical report documentation page.

In recent years, the use of modular bridge deck components has gained popularity for facilitating more durable components in bridge decks, but these components require field-applied connections for constructing the entire bridge. Ultra-High-Performance Concrete (UHPC) is being extensively used for highway bridges in the field connections between girders and deck panels for its superior quality than conventional concrete.Thus far, very limited data is available on the modeling of hybrid-bridge deck connections. In this study, finite element models have been developed to identify the primary properties affecting the response of hybrid deck panel system under monotonic and reverse cyclic loads. The commercial software ABAQUS was used to validate the models and to generate the data presented herein. The concrete damage plasticity (CDP) model was used to simulate both the conventional concrete and UHPC. In addition, numerical results were validated against experimental data available in the literature. The key parameters studied were the mesh size, the dilation angle, reinforcement type, concrete constitutive models, steel properties, and the contact type between the UHPC and the conventional concrete. The models were found to capture the load-deformation response, failure modes, crack patterns and ductility indices satisfactorily. The damage in concrete under monotonic loading is found higher in normal concrete than UHPC with no signs of de-bonding between the two materials. It is observed that increasing the dilation angle leads to an increase in the initial stiffness of the model. Changing the dilation angle from 20℗ʻ to 40℗ʻ results in an increase of 7.81% in ultimate load for the panel with straight reinforcing bars, whereas for the panel with headed bars, the increase in ultimate load was found 8.56 %.Furthermore, four different types of bridge deck panels were simulated under reversed cyclic loading to observe overall behavior and the damage pattern associated with the reversed cyclic load. The key parameters investigated were the configurations of steel connections between the precast concrete deck elements, the loading position, ductility index, and the failure phenomena. The headed bar connections were found to experience higher ductility than the ones with straight bars in the range of 10.12% to 30.70% in all loading conditions, which is crucial for ensuring safe structural performance. This numerical investigation provides recommendations for predicting the location of the local damage in UHPC concrete bridge deck precast panel connections under reversed cyclic loading.Despite of having excellent mechanical and material properties, the use of Ultra-High-Performance Fiber Reinforced Concrete (UHP-FRC) is not widespread due to its high cost and lack of widely accepted design guidelines. This research also aims to develop a UHPC mixture using locally and domestically available materials without heat curing in hopes of reducing the production cost. Several trial mixtures of UHPC have been developed using locally available basalt and domestically available steel fibers. Among them, one trial mixture of 20.35 ksi compressive strength was selected for further study. To investigate the applicability of this locally produced UHPC in bridge closure, two full scale-8 ft. span hybrid bridge deck slabs with UHPC closure were constructed and tested under monotonic loading to identify the structural and material responses. The load-deflection response of the hybrid connection confirms that the deflection increased linearly until the initiation of first crack, after that it increased non-linearly up to the failure of the connection. The strain response also confirms that UHPC experiences less strain than normal strength concrete under compression loading. In addition, a moment curvature analytical graphical user interface model of hybrid bridge deck connection has been developed using MATLAB to predict ductility, curvature, and the stress distributions in those connections. The predicted value of moment and curvature from the code was found in good agreement with experimental data as well. The code provides a tool to professional engineers to predict ductility, curvature, and the stress distributions in those connections. The code is built in such a way to allow various input parameters such as concrete strength, dimensions of hybrid connection and deck panels, reinforcement configuration and the shape of the connection.Though, ultra-high-performance fiber reinforced concrete (UHP-FRC) has very high compressive strength compared to conventional concrete, the failure strain of UHP-FRC is not enough to withstand large plastic deformations under high stain rate loading such as impact and blast loading. Hence, a numerical study has been conducted to simulate low-velocity impact phenomenon of UHP-FRC. The responses obtained from the numerical study are in good agreement with the experimental results under impact loads. Five different types of UHP-FRC beams were simulated under impact loading to observe the global and local material responses. The key parameters investigated were the reinforcement ratio (Ï1), impact load under various drop heights (h), and the failure phenomena. It was observed that higher reinforcement ratio showed better deflection recovery under the proposed impact. Also, for a specific reinforcement ratio, the maximum deflection increases approximately 15% when drop height decreases from 100 mm to 25 mm. Moreover, the applicability of concrete damage plasticity model for impact loading is investigated. The results also provided recommendations for predicting the location of the local damage in UHP-FRC beams under impact loading.Moreover, this research work includes a nonlinear finite element analysis of high-strength concrete confined with opposing circular spiral reinforcements. The spiral reinforcement is a very common technique used for reinforcing columns in active seismic regions due to its high ductility and high energy absorption. The results are compared with previously tested small-scale concrete columns made with the same technique under monotonic axial loads. The proposed technique is developed to improve the strength and ductility of concrete columns confined with conventional spiral systems. The finite element (FE) analysis results have shown that the proposed model can predict the failure load and crack pattern of columns with reasonable accuracy. Beside this, the concrete plasticity damage showed very good results in simulating columns with opposing spirals. The FE model is used to conduct a study on the effect of spiral spacing, Îđ (ratio of the core diameter to the whole cross section diameter) and compressive strength on the behavior of circular spiral reinforced concrete columns confined with opposing circular spiral reinforcements. The results of the parametric study demonstrated that for the same spacing between spirals and same strength of concrete, increasing Îđ increases the failure load of the column. It is also observed from the study that the ductility of the studied columns is not affected by changing the value of Îđ. In addition, a correlation between the Îđ factor, three different compressive concrete strengths, and the spacing of opposing spirals was developed in this study.

Selected chapters from the German concrete yearbook are now being published in the new English "Beton-Kalender Series" for the benefit of an international audience. Since it was founded in 1906, the Ernst & Sohn "Beton-Kalender" has been supporting developments in reinforced and prestressed concrete. The aim was to publish a yearbook to reflect progress in "ferro-concrete" structures until - as the book's first editor, Fritz von Emperger (1862-1942), expressed it - the "tempestuous development" in this form of construction came to an end. However, the "Beton-Kalender" quickly became the chosen work of reference for civil and structural engineers, and apart from the years 1945-1950 has been published annually ever since. Ultra high performance concrete (UHPC) is a milestone in concrete technology and application. It permits the construction of both more slender and more durable concrete structures with a prolonged service life and thus improved sustainability. This book is a comprehensive overview of UHPC - from the principles behind its production and its mechanical properties to design and detailing aspects. The focus is on the material behaviour of steel fibre-reinforced UHPC. Numerical modelling and detailing of the connections with reinforced concrete elements are featured as well. Numerous examples worldwide - bridges, columns, facades and roofs - are the basis for additional explanations about the benefits of UHPC and how it helps to realise several architectural requirements. The authors are extensively involved in the testing, design, construction and monitoring of UHPC structures. What they provide here is therefore a unique synopsis of the state of the art with a view to practical applications.

"The remarkable features of ultra-high performance concrete (UHPC) have been reported. Its application in bridge construction has been an active research area in recent years, attributed to its higher compressive strength, higher ductility and reduced permeability when compared with conventional concrete and even high-strength concrete. Those characteristics are known to increase bridge durability and, consequently, decrease life-cycle maintenance costs. With that in mind, this study investigated the performance of UHPC stay-in-place (SIP) bridge deck panels subjected to high loads in both flexure and shear. The test matrix consisted of twelve (12) half-scale panels that were 4 feet long and 2 feet wide. The variable parameters that were studied included thickness (i.e., 2-in. and 3-in.) as well as non-discrete reinforcement type, including conventional mild reinforcement, welded wire mesh and no reinforcement (UHPC only). Control deck panels with conventional concrete (CC) were fabricated and tested to serve as a baseline for comparison. The results indicated that the UHPC panels had an improved performance compared to the conventional concrete panels. With respect to the panels tested in high shear loads, only the CC panel test resulted in a diagonal tension failure mode (i.e. traditional shear type failure). All of the other UHPC panels failed in flexure suggesting that the UHPC provided a high shear capacity. The results also showed a good correlation with selected empirical models. A cost study was also investigated. It was concluded that, even with the high difference between the prices per cubic yard of both concretes, the difference can be significantly lower when compared with the prices per ultimate load capacity"--Abstract, page iii.