Composite Constructions of Timber and High-Performance Concrete

2010 ◽  
Vol 133-134 ◽  
pp. 1171-1176
Author(s):  
Hubertus Kieslich ◽  
Klaus Holschemacher
Keyword(s):  
High Performance ◽  
Lightweight Concrete ◽  
High Performance Concrete ◽  
Concrete Slab ◽  
High Strength ◽  
Fiber Reinforced Concrete ◽  
Experimental Investigations ◽  
Hardened Concrete ◽  
Timber Beam ◽  
Load Carrying

Currently Timber-Concrete Composite (TCC) Constructions are often applied for strengthening existing timber beam slabs. The load bearing capacity of the composite construction is primarily affected by the material properties of the timber beam and the concrete slab. But the type of bond between both parts is also of high importance. The concrete slab has to perform several tasks, not only in load carrying direction of the ceiling but also perpendicular to the direction of span or for stiffening the whole building. These tasks will be pointed out in this paper. Furthermore the working process (easy workable mixture and exchange of conventional reinforcement) and the dead load of the construction are of particular interest in the field of redevelopment. Several innovative concretes have been verified for the use in TCC constructions. Regarding their fresh and hardened concrete properties, they all can be described as High Performance Concretes (HPC). In this paper Self Compacting Concrete (SCC), Fiber Reinforced Concrete (FRC), Structural Lightweight Concrete (SLWC), High Strength Concrete (HSC) or combinations of them will be focused. Especially the advantages but also the disadvantages of innovative concretes for the use in TCC will be presented as well as the results of some experimental investigations.

scholarly journals The experimental investigations of RC internal columns in the connection zone with lightweight concrete slab

2013 ◽  
Vol 12 (1) ◽  
pp. 187-194
Author(s):  
Tadeusz Urban ◽  
Michał Gołdyn ◽  
Łukasz Krawczyk
Keyword(s):  
Lightweight Concrete ◽  
Concrete Slab ◽  
Concrete Strength ◽  
Variable Parameter ◽  
High Strength ◽  
Shear Capacity ◽  
Punching Shear ◽  
Experimental Investigations ◽  
Load Carrying Capacity ◽  
Load Carrying

This paper presents the problem of load carrying capacity of the columns made of high-strength reinforced concrete which are separated by slab made of lightweight concrete. The experimental investigations of three models representing the internal connection between column and flat slab made of lightweight concrete of the strength tree times less than concrete strength of column are presented. The effort degree on the punching shear capacity stands for the variable parameter in the presented study. The performed study shows that there is no effect of this parameter on the effective concrete strength of the column.

scholarly journals Resistance of an Optimized Ultra-High Performance Fiber Reinforced Concrete to Projectile Impact

Buildings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 63
Author(s):  
Anna L. Mina ◽  
Michael F. Petrou ◽  
Konstantinos G. Trezos
Keyword(s):  
Reinforced Concrete ◽  
High Performance ◽  
High Performance Concrete ◽  
High Strength ◽  
Fiber Reinforced Concrete ◽  
Steel Fibers ◽  
Fiber Reinforced ◽  
Depth Of Penetration ◽  
Projectile Impact ◽  
High Performance Fiber

The scope of this paper is to investigate the performance of ultra-high performance fiber reinforced concrete (UHPFRC) concrete slabs, under projectile impact. Mixture performance under impact loading was examined using bullets with 7.62 mm diameter and initial velocity 800 m/s. The UHPFRC, used in this study, consists of a combination of steel fibers of two lengths: 6 mm and 13 mm with the same diameter of 0.16 mm. Six composition mixtures were tested, four UHPFRC, one ultra-high performance concrete (UHPC), without steel fibers, and high strength concrete (HSC). Slabs with thicknesses of 15, 30, 50, and 70 mm were produced and subjected to real shotgun fire in the field. Penetration depth, material volume loss, and crater diameter were measured and analyzed. The test results show that the mixture with a combination of 3% 6 mm and 3% of 13 mm length of steel fibers exhibited the best resistance to projectile impact and only the slabs with 15 mm thickness had perforation. Empirical models that predict the depth of penetration were compared with the experimental results. This material can be used as an overlay to buildings or to construct small precast structures.

Research and Applying Evolution of High Efficient Water-Reducing Agent for High Performance Concrete

2012 ◽  
Vol 610-613 ◽  
pp. 573-576
Author(s):  
Zheng Jun Wang ◽  
Jia Bin Liang
Keyword(s):  
High Performance ◽  
Lightweight Concrete ◽  
High Performance Concrete ◽  
Concrete Strength ◽  
High Strength ◽  
Reducing Agent ◽  
Mass Concrete ◽  
Green Concrete ◽  
High Efficient ◽  
Strength And Durability

This paper discusses the development of water-reducing agent and the present situation of the application of high performance concrete. The traditional concrete will be substituted by high performance concrete, green concrete. In the course of appearance of high performance and green, concrete admixtures plays an extremely important role. Concrete water-reducing agent is admixture of the main part. In the case of keeping liquidity, it can make water consumption reduce, so the concrete strength and durability can be improved. It is applicable to all kinds of industrial and civil construction engineering, and it can be applied to different strength grade of concrete. It has important significance for mass concrete engineering, marine building facilities, and component and product of high strength lightweight concrete.

Repair of Severely Damaged Reinforced Concrete Beams with High-Strength Cementitious Grout

2020 ◽  
Vol 2674 (6) ◽  
pp. 372-384
Author(s):  
Antoine N. Gergess ◽  
Mahfoud Shaikh Al Shabab ◽  
Razane Massouh
Keyword(s):  
Reinforced Concrete ◽  
High Performance ◽  
High Performance Concrete ◽  
High Strength ◽  
Cementitious Materials ◽  
Fiber Reinforced Concrete ◽  
Steel Fibers ◽  
Reinforced Concrete Beams ◽  
Rc Beams ◽  
Rc Structures

High-strength cementitious materials such as high-performance concrete are extensively used for retrofit of reinforced concrete (RC) structures. The effectiveness of these materials is increased when mixed with steel fibers. A commonly used technique for strengthening and repair of RC beams consists of applying high-performance fiber-reinforced concrete jackets around the beam perimeter. This paper investigates the jacketing method for repairing severely damaged RC beams. Four 2 m (6 ft 63/4 in.) long rectangular RC beams, 200 × 300 mm (8 ×12 in.) were initially cast and loaded until failure based on three-point bending tests. The four beams were then repaired by thickening the sides of the damaged RC beams using a commercially available high-strength shrinkage grout with and without steel fibers. Strain and deformation were recorded in the damaged and repaired beams to compare structural performance. It is shown that the flexural strength of the repaired beams is increased and the crack pattern under loading is improved, proving that the proposed repair method can restore the resistance capacity of RC beams despite the degree of damage. A method for repair is proposed and an analytical investigation is also performed to understand the structural behavior of the repaired beams based on different thickening configurations.

Technology of Ultra-High Strength / High Performance Concrete Applied to Guangzhou Xita Tower Construction

2009 ◽  
Vol 405-406 ◽  
pp. 1-4 ◽  
Author(s):  
Hao Wen Ye
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Autogenous Shrinkage ◽  
High Strength ◽  
Hardened Concrete ◽  
High Rise ◽  
Slump Flow ◽  
Mix Proportion ◽  
New City ◽  
Pumping Equipment

This paper introduces development and application of ultra-high strength/high performance concrete in construction of the Xita tower high-rise building at Zhujiang New City of Guangzhou, China. The goal of the concrete construction in the Xita Tower project will be realized via research of mix proportion and optimization of pumping equipment. In regard to mix proportion of concrete, low water/cement (W/C) ratio, low water content lower than 150 kg/m3 and employment of superplasticizer are essential to acquire high strength. A series of parameters have been measured to research workability of concrete from C70 to C90, such slump, slump flow, flow time from inverted cone, L-box flow, and bleeding under pressure et al. Properties of hardened concrete should also be considered, including durability, autogenous shrinkage caused cracking, and fire resistance.

A Review on Ductile Self-Compacting Concrete

2013 ◽  
Vol 594-595 ◽  
pp. 433-438
Author(s):  
Muhd Fadhil Nuruddin ◽  
Kok Yung Chang ◽  
Norzaireen Mohd Azmee ◽  
Nasir Shafiq
Keyword(s):  
High Strength Concrete ◽  
High Performance ◽  
Lightweight Concrete ◽  
High Strength ◽  
Fiber Reinforced Concrete ◽  
Steel Fibers ◽  
Self Compacting Concrete ◽  
Factors Influencing ◽  
Recent Innovation ◽  
High Performance Fiber

Ductile self-compacting concrete (DSCC) also known as ultra-high-performance fiber reinforced concrete with a steel like compressive strength of up to 250 MPa and remarkable increase in durability compared to high-strength concrete can be considered as the most successful recent innovation in concrete construction. The achievement of DSCC has been made possible by the introduction of materials such as superplasticizers, microsilica and steel fibers. Incorporation of steel fibers in the mix made it feasible to design sustainable filigree, lightweight concrete constructions without any additional steel reinforcement. The purpose of this paper is to review the needs of DSCC and the factors influencing the workability of DSCC as well as the effect of the inclusion of steel fibers. Various studies concluded that the inclusion of steel fibers will increase the mechanical and durability properties but reduce the workability.

scholarly journals Innovative design approach of precast–prestressed girder bridges using ultra high performance concrete

2010 ◽  
Vol 37 (4) ◽  
pp. 511-521 ◽  
Author(s):  
H. Almansour ◽  
Z. Lounis
Keyword(s):  
Prestressed Concrete ◽  
High Performance ◽  
High Performance Concrete ◽  
Concrete Slab ◽  
High Strength ◽  
Design Approach ◽  
Highway Bridge ◽  
Efficient Design ◽  
Ultra High Performance Concrete ◽  
Prestressed Concrete Girders

The construction of new bridges and the maintenance and renewal of aging highway bridge network using ultra high performance concrete can lead to the construction of long life bridges that will require minimum maintenance resulting in low life cycle costs. Ultra high performance concrete (UHPC) is a newly developed concrete material that provides very high strength and very low permeability to aggressive agents such as chlorides from de-icing salts or seawater. Ultra high performance concrete could enable major improvements over conventional high performance concrete (HPC) bridges in terms of structural efficiency, durability, and cost-effectiveness over the long term. A simplified design approach of concrete slab on UHPC girders bridge using the Canadian Highway Bridge Design code and the current recommendations for UHPC design is proposed. An illustrative example demonstrates that the use of UHPC in precast–prestressed concrete girders yields a more efficient design of the superstructure where considerable reduction in the number of girders and girder size when compared to conventional HPC girders bridge with the same span length. Hence, UHPC results in a significant reduction in concrete volume and then weight of the superstructure, which in turn leads to significant reduction in the dead load on the substructure, especially for the case of aging bridges, thus improving their performance.

Push-Out Test on Shear Connectors Embedded in UHPC

2013 ◽  
Vol 351-352 ◽  
pp. 50-54 ◽  
Author(s):  
Jee Sang Kim ◽  
Sang Hyeok Park ◽  
Chang Bin Joh ◽  
Jong D.K. Kwark ◽  
Eun Suk Choi
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Experimental Investigations ◽  
Load Carrying Capacity ◽  
Ultra High Performance Concrete ◽  
Shear Connectors ◽  
Aspect Ratios ◽  
High Durability ◽  
Load Carrying ◽  
Push Out

The various push-out tests have been performed to investigate the load carrying capacity and ultimate behavior of headed studs in UHPC (Ultra High Performance Concrete), which has high compressive and tensile strength as well as high durability compared to ordinary concrete. The test program included the studs with a diameter of 16mm and 22mm for various aspect ratios (height to depth ratio of a stud) and cover depths. This paper presents the main results of the experimental investigations.

scholarly journals Influence of Fiber Addition on the Properties of High-Performance Concrete

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3736
Author(s):  
Szymon Grzesiak ◽  
Matthias Pahn ◽  
Milan Schultz-Cornelius ◽  
Stefan Harenberg ◽  
Christoph Hahn
Keyword(s):  
Tensile Strength ◽  
Reinforced Concrete ◽  
High Performance ◽  
High Performance Concrete ◽  
Limit State ◽  
Experimental Tests ◽  
Absorption Capacity ◽  
Fiber Reinforced Concrete ◽  
Hardened Concrete ◽  
Fiber Reinforced

High performance fiber-reinforced concrete (HPFRC) has been frequently investigated in recent years. Plenty of studies have focused on different materials and types of fibers in combination with the concrete matrix. Experimental tests show that fiber dosage improves the energy absorption capacity of concrete and enhances the robustness of concrete elements. Fiber reinforced concrete has also been illustrated to be a material for developing infrastructure sustainability in RC elements like façade plates, columns, beams, or walls. Due to increasing costs of the produced fiber reinforced concrete and to ensure the serviceability limit state of construction elements, there is a demand to analyze the necessary fiber dosage in the concrete composition. It is expected that the surface and length of used fiber in combination with their dosage influence the structure of fresh and hardened concrete. This work presents an investigation of the mechanical parameters of HPFRC with different polymer fiber dosage. Tests were carried out on a mixture with polypropylene and polyvinyl alcohol fiber with dosages of 15, 25, and 35 kg/m3 as well as with control concrete without fiber. Differences were observed in the compressive strength and in the modulus of elasticity as well as in the flexural and splitting tensile strength. The flexural tensile strength test was conducted on two different element shapes: square panel and beam samples. These mechanical properties could lead to recommendations for designers of façade elements made of HPFRC.

EFFECTS OF COARSE PALM OIL CLINKER ON PROPERTIES OF SELF-COMPACTING LIGHTWEIGHT CONCRETE

2017 ◽  
Vol 79 (6) ◽  
Author(s):  
Owi Siew Feen ◽  
Roslli Noor Mohamed ◽  
Azman Mohamed ◽  
Nur Hafizah A. Khalid
Keyword(s):  
Palm Oil ◽  
Environmental Sustainability ◽  
High Performance ◽  
Lightweight Concrete ◽  
High Performance Concrete ◽  
Ultrasonic Pulse Velocity ◽  
Pulse Velocity ◽  
The Self ◽  
Hardened Concrete ◽  
Coarse Aggregates

Self-compacting lightweight concrete (SCLWC) is an innovative high performance concrete which uses palm oil clinker (POC), a waste by-product from the palm oil industry, as the lightweight aggregates. This paper presents a research on the effects of utilising only POC as coarse aggregates on the fresh and hardened properties of SCLWC. Properties of SCLWC were compared to self-compacting concrete (SCC) containing crushed granite aggregates. Tests of slump flow, V-funnel, J-ring, L box and sieve segregation were conducted to characterise the self-compactability in fresh state. The hardened concrete specimens were tested for density, water absorption, ultrasonic pulse velocity (UPV), compression, tensile splitting and flexural. Results revealed that both mixes had fulfilled the self-compactability requirements as per European Guidelines whereby the fresh SCLWC exhibited better filling ability and passing ability at low segregation resistance. The inclusion of coarse POC reduced the concrete density and strength, but the SCLWC exhibited good UPV values despite greater porosity in the concrete. It can be concluded that the POC can be potentially used as coarse aggregates for producing SCLWC to manage the waste and promote environmental sustainability. 

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