scholarly journals Comparison of Conventional and Advanced Concrete Technologies in terms of Construction Efficiency

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Matej Špak ◽  
Mária Kozlovská ◽  
Zuzana Struková ◽  
Renáta Bašková
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Construction Material ◽  
Ultra High Performance Concrete ◽  
Construction Costs ◽  
Construction Time ◽  
Modern Methods ◽  
Precast Elements ◽  
Monolithic Structures ◽  
Construction Efficiency

Nowadays, high-performance concrete (HPC) and ultra-high-performance concrete (UHPC) are ranked among advanced concrete technologies. The application of the mentioned advanced technologies may have potential to improve the construction efficiency from several points of view. For instance, reducing of construction time and construction material, construction quality improving, environmental impact minimizing, and increasing of both durability and lifetime of structures as well as reducing of total construction costs may be obtained. Particular advanced concrete technologies are described and the possibilities of their utilization in both monolithic structures and precast units are presented in the article. The main benefits of modern methods of construction (MMC) based on advanced concrete technologies application in precast elements production are presented. Regarding the selected aspects of construction efficiency assessment, a comparison of conventional and advanced concrete technologies that are applied in monolithic structures and precast units is made. The results of this comparison, estimated in semantic differential scale, are presented in the article. By the results of the comparison, the significance of applying the advanced concrete technologies in modern methods of concrete structures production is demonstrated in order to improve construction efficiency.

UHPC Footbridge over the Opatovický Canal

2016 ◽  
Vol 249 ◽  
pp. 320-324
Author(s):  
Jan Tichý ◽  
David Čítek ◽  
Jiří Kolísko ◽  
Jan Komanec ◽  
Bohuslav Slánský ◽  
...  
Keyword(s):  
Material Properties ◽  
High Performance ◽  
High Performance Concrete ◽  
Construction Material ◽  
Cementitious Material ◽  
Ultra High Performance Concrete ◽  
High Durability ◽  
Design Production ◽  
New Type ◽  
Reliable Design

Article deals with design of footbridge made from ultra high performance concrete (UHPC). UHPC is relatively new type of cementitious material with high compressive strength and high durability. For reliable design of construction from this material an extensive experimental research and verification of material properties are needed. Skanska and Pontex company with cooperation with Klokner institute developed matrix of UHPC used for footbridge construction. Material properties were verified during whole developing and producing process. Footbridge was casted in precast plant Skanska – Steti in December 2014. It was installed over Opatovický canal in October 2015. Contribution describes design, production and installation of footbridge. Material properties of used UHPC are also included.

New Connection Detail to Connect Precast Column to Cap Beam using Ultra-High-Performance Concrete in Accelerated Bridge Construction Applications

2018 ◽  
Vol 2672 (41) ◽  
pp. 207-220 ◽  
Author(s):  
Mohamadreza Shafieifar ◽  
Mahsa Farzad ◽  
Atorod Azizinamini
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Precast Concrete ◽  
Experimental Program ◽  
Accelerated Bridge Construction ◽  
Ultra High Performance Concrete ◽  
Bridge Construction ◽  
Construction Time ◽  
Element Analysis ◽  
Displacement Ductility

Accelerated bridge construction (ABC) is a paradigm change in delivery of bridges. ABC minimizes the traffic interruption, enhances safety to public and workers by significantly reducing on-site construction activities, and results in longer-lasting bridges. The use of precast elements is gaining attention owing to inherent benefits of accelerated construction. Designing an economical connection is one of the main concerns for these structures. New improved materials such as ultra-high-performance concrete (UHPC) with superior characteristics can provide solutions for joining precast concrete elements. In this paper two types of column to cap beam connection using UHPC are proposed for seismic and non-seismic regions. Among the merits of the proposed details, large tolerances in construction and simplicity of the connection can be highlighted which facilitates and accelerates the on-site construction time. The experimental program was carried out to evaluate the performance and structural behavior of the proposed connections. Four specimens were subjected to constant axial compressive loads and cyclic lateral loading. Results of the experiment showed that the displacement ductility of the specimens, incorporating suggested details, demonstrated adequate levels of displacement ductility. More importantly, the proposed connections prevented the damage into capacity protected element—in this case the cap beam. Analytical and nonlinear finite element analysis on the specimens was carried out to better comprehend the behavior of the proposed connections.

Innovative Approach to Repair Corroded Steel Piles using Ultra-High Performance Concrete

2020 ◽  
Vol 2674 (12) ◽  
pp. 1-14
Author(s):  
Binod Shrestha ◽  
Ahmed Gheni ◽  
Mohanad M. Abdulazeez ◽  
Mohamed A. ElGawady
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Load Capacity ◽  
Ultra High Performance Concrete ◽  
Conventional Concrete ◽  
Alkaline Salt ◽  
Axial Load Capacity ◽  
Steel Piles ◽  
Existing Bridges ◽  
Precast Elements

Steel H-piles are a common structural system in existing bridges. Many steel H-piles have been corroded as a result of severe weather and acid/alkaline salt exposures, causing a reduction in the axial load capacity. This paper experimentally investigates the use of ultra-high performance concrete (UHPC) encasement as a novel repair method for corroded steel H-pile. UHPC displays better tensile strength, early compressive strength, workability, and durability compared with conventional concrete. The proposed repair is used to bridge the corroded section in H-pile using either a cast-in-place or precast UHPC elements. A series of push-out tests was conducted on eight full-scale piles to assess the axial force that can be transferred through shear studs and bond between the UHPC and steel piles. The test parameters include the type of casting of the UHPC, that is, cast-in-place versus precast elements, thickness and shape of the UHPC elements, an inclusion of carbon fiber reinforced polymer (CFRP) grid, number and grade of bolts, an inclusion of washer, and applying torque on the bolts. The experimental work demonstrated that the UHPC precast repair can be easily implemented. Moreover, using 57 mm (2.25 in.) thick UHPC plates reinforced by two layers of the CFRP grid was capable of transferring up to 81% of the squash load of the H-pile.

Cyclic Test of Concrete Bridge Column Utilizing Ultra-High Performance Concrete Shell

2020 ◽  
Vol 2674 (2) ◽  
pp. 158-166 ◽  
Author(s):  
Nerma Caluk ◽  
Islam M. Mantawy ◽  
Atorod Azizinamini
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Plastic Hinge ◽  
Protective Layer ◽  
Structural Elements ◽  
Ultra High Performance Concrete ◽  
Reinforced Concrete Column ◽  
Construction Time ◽  
The North ◽  
Drift Ratio

Ultra-high performance concrete (UHPC) is a durable material that can be used in constructing new and unique structural elements. This research utilizes UHPC to construct prefabricated shells that act as stay-in-place forms for bridge columns and eliminate the use of traditional formwork. These innovative structural elements reduce the on-site construction time, improve the structural performance of the column, and act as a protective layer in aggressive environments. Generally, during the construction process, the prefabricated UHPC shell is placed around the column reinforcement, which is fabricated using conventional methods. To connect the UHPC shell and column reinforcement with the footing and footing dowels, a step made of UHPC is utilized. The UHPC step connection is designed to shift the plastic hinge away from the column-to-footing interface. In the next stage, normal concrete is cast inside the shell, forming a concrete-filled UHPC shell. The final stage of construction involves placing and connecting a prefabricated cap-beam using the same UHPC step connection. The column specimen was tested under constant axial load and incremental lateral load. In this test, the UHPC shell cracked on the north side at a drift ratio of 3%; however, the column had a significant capacity and behaved similarly to a conventional reinforced concrete column during higher cycles of drift ratios. The test was completed after the column had reached a drift ratio of 7.5% when the first bar ruptured. No damage occurred in the footing and UHPC step which proved that the design was successful in shifting the plastic hinge away from the column-to-footing interface.

scholarly journals Effect of Graphene Oxide on Mechanical Properties and Durability of Ultra-High-Performance Concrete Prepared from Recycled Sand

Nanomaterials ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1718 ◽  
Author(s):  
Hongyan Chu ◽  
Yu Zhang ◽  
Fengjuan Wang ◽  
Taotao Feng ◽  
Liguo Wang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Graphene Oxide ◽  
High Performance ◽  
High Performance Concrete ◽  
Construction Material ◽  
Chloride Ions ◽  
Raw Material ◽  
Ultra High Performance Concrete ◽  
River Sand ◽  
The Impact

Ultra-high-performance concrete (UHPC) has been used as an advanced construction material in civil engineering because of its excellent mechanical properties and durability. However, with the depletion of the raw material (river sand) used for preparing UHPC, it is imperative to find a replacement material. Recycled sand is an alternative raw material for preparing UHPC, but it degrades the performance. In this study, we investigated the use of graphene oxide (GO) as an additive for enhancing the properties of UHPC prepared from recycled sand. The primary objective was to investigate the effects of GO on the mechanical properties and durability of the UHPC at different concentrations. Additionally, the impact of the GO additive on the microstructure of the UHPC prepared from recycled sand was analysed at different mixing concentrations. The addition of GO resulted in the following: (1) The porosity of the UHPC prepared from recycled sand was reduced by 4.45–11.35%; (2) the compressive strength, flexural strength, splitting tensile strength, and elastic modulus of the UHPC prepared from recycled sand were enhanced by 8.24–16.83%, 11.26–26.62%, 15.63–29.54%, and 5.84–12.25%, respectively; (3) the resistance of the UHPC to penetration of chloride ions increased, and the freeze–thaw resistance improved; (4) the optimum mixing concentration of GO in the UHPC was determined to be 0.05 wt.%, according to a comprehensive analysis of its effects on the microstructure, mechanical properties, and durability of the UHPC. The findings of this study provide important guidance for the utilisation of recycled sand resources.

scholarly journals Experimental Investigations on Temperature Generation and Release of Ultra-High Performance Concrete during Fatigue Tests

2020 ◽  
Vol 10 (17) ◽  
pp. 5845
Author(s):  
Melchior Deutscher ◽  
Ngoc Linh Tran ◽  
Silke Scheerer
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Construction Material ◽  
Maximum Temperature ◽  
Experimental Investigations ◽  
Heating Process ◽  
Parameter Study ◽  
Ultra High Performance Concrete ◽  
Resource Saving ◽  
Premature Failure

Smarter, more filigree, and resource-saving buildings are the aim of developments in the construction industry. In reinforced concrete construction, ultra-high strength concretes have been developed to achieve these goals. Due to their use and requirements, these highly pressure-resistant materials are increasingly exposed to cyclically occurring and high-frequency loads. Examples of this are applications in long-span bridges or wind turbines. Research into the fatigue behaviour of the new construction material is therefore very important for the standardization and practical introduction of the high performance material. In this article, we want to investigate the heating process of ultra-high performance concrete (UHPC) under fatigue stress in more detail. In previous investigations in this project, an influence of the heating on the fatigue strength could be determined. A systematic parameter study has defined decisive load configurations for a maximum heating process. The aim is now to better understand the heating process. For this purpose, the temperature generation rate and the temperature release, which probably influences the overall temperature development, are investigated. A test program with eight experiments gives information about the temperature release during the experiment and the heating rate with and without pre-damage in the sample. In addition, the causes of failure caused by temperature are investigated with additional insulated tests. The results are presented, discussed, and conclusions are drawn in the article. For instance, fatigue damage affects the rate of temperature increase, but not the thermal conductivity of the material. In the different configurations, the test specimens essentially overlap at the maximum temperature reached in the inner test specimen. In addition to the assumed influence of the temperature gradients in the cross section as a cause of premature failure due to additional constraint stresses, the maximum temperature in particular turns out to be decisive, independent of the gradient.

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