Influence of Ambient and Fresh Concrete Temperatures on the Maximum Temperature and Thermal Gradient in a High-Performance Concrete Structure

10.14359/290 ◽  
1997 ◽  
Vol 94 (2) ◽  
Keyword(s):  
Concrete Structure ◽  
Thermal Gradient ◽  
High Performance ◽  
High Performance Concrete ◽  
Fresh Concrete ◽  
Maximum Temperature

High Performance Concrete with Ternary Binders

2018 ◽  
Vol 761 ◽  
pp. 120-123 ◽  
Author(s):  
Vlastimil Bílek ◽  
David Pytlík ◽  
Marketa Bambuchova
Keyword(s):  
Fly Ash ◽  
Portland Cement ◽  
Silica Fume ◽  
High Performance ◽  
Ordinary Portland Cement ◽  
High Performance Concrete ◽  
Fresh Concrete ◽  
Binder Ratio ◽  
Water To Binder Ratio ◽  
Condensed Silica Fume

Use a ternary binder for production of a high performance concrete with a compressive strengths between 120 and 170 MPa is presented. The water to binder ratio of the concrete is 0.225 and the binder is composed of Ordinary Portland Cement (OPC), condensed silica fume (CSF), ground limestone (L), fly ash (FA) and metakaoline (MK). The dosage of (M + CSF) is kept at a constant level for a better workability of fresh concrete. Different workability, flexural and compressive strengths were obtained for concretes with a constant cement and a metakaoline dosage, and for a constant dosage (FA + L) but a different ratio FA / L. An optimum composition was found and concretes for other tests were designed using this composition.

Impact of Steel Fibers on Workability and Properties of UHPC

2016 ◽  
Vol 249 ◽  
pp. 57-61 ◽  
Author(s):  
Milan Rydval ◽  
Tomáš Bittner ◽  
Jiří Kolísko ◽  
Šárka Nenadálová
Keyword(s):  
Mechanical Properties ◽  
High Performance ◽  
High Performance Concrete ◽  
Volume Fraction ◽  
Fresh Concrete ◽  
Mixture Design ◽  
Steel Fibers ◽  
Hardened Concrete ◽  
Hardened Cement ◽  
The Impact

This paper is focused on properties of fresh and hardened cement-based composite Ultra-High Performance Concrete with regard to different volume fraction of short brass coated steel fibers BASF MASTERFIBER® 482. Workability of fresh concrete and basic mechanical properties (tensile strength in bending, compressive strength) of hardened UHPC were found out. The workability of fresh concrete was measured by small mortar Haegermann cone. Percentage differences at cost were obtained at hardened concrete, too. The aim of the first experimental part of the research was the impact of volume fraction of steel fibers according to workability of fresh concrete and also according to mechanical properties of hardened UHPC with the same volume fraction of each component of the mixture, only the volume fraction of the steel fibers was different at each mixture. The mixture design of UHPC was changed to maintaining the workability of fresh concrete at the second part of the research. The workability at mixture with dosage of steel fibers of 300 kg/m3 measured by Haegermann cone was around 300 mm. In the framework of grant project GAČR 15-05791S the basic mechanical properties of hardened fine-grained cementitious composite material UHPC at small beams size of 160/40/40 mm and beams size 300/70/70 mm were determined. The aim of the research project was not only the determination of basic mechanical properties for each mixture design but also workability assessment and costs linked with higher amount of the volume fracture of steel fibers.

Applying Research on Testing Compressive Strength of High Performance Concrete with Rebound Method

2012 ◽  
Vol 452-453 ◽  
pp. 106-109
Author(s):  
Zheng Jun Wang ◽  
Felix Zhao
Keyword(s):  
Compressive Strength ◽  
Concrete Structure ◽  
High Performance ◽  
High Performance Concrete ◽  
Cement Concrete ◽  
Construction Quality ◽  
Concrete Construction ◽  
Estimation Models

In order to grasp timely and accurately quality of high performance concrete, detection of compressive strength of high performance concrete can be non-destructively, rapidly and accurately tested that is very testing index. The paper did some research on compressive strength of high performance concrete applying redound method that it established several estimation models between rebound value and compressive strength. Experiment shows that rebound method can effetely test compressive strength of high performance concrete. Construction quality of Cement concrete structure can timely grasp applying the method.

Advances in Research on Correlation of Workability and Rheology of Fresh Concrete: A Review

2009 ◽  
Vol 405-406 ◽  
pp. 77-82
Author(s):  
Gai Fei Peng ◽  
Zhan Qi Guo ◽  
Piet Stroeven ◽  
Ri Gao ◽  
Guang Hua Huang
Keyword(s):  
Literature Review ◽  
High Performance ◽  
High Performance Concrete ◽  
Fresh Concrete ◽  
Experimental Tests ◽  
Test Method ◽  
Future Research ◽  
Specific Method ◽  
Self Compacting Concrete ◽  
The Relationship

A literature review was carried out to identify advances in research on workability of fresh concrete via both experimental tests and modeling, especially high performance concrete and self-compacting concrete. It is concluded that, in order to achieve better understanding of fresh concrete, especially self-compacting concrete (SCC) and high-performance concrete (HPC), a clear methodology of research should be established as the first step. It is suggested that there is no unique workability test method suitable for all the range of fluidity of fresh concrete, and a specific method should be identified for a proper range of fluidity. As to the relationship between fluidity of concrete and that of paste, future research can be conducted in two aspects, i.e. one is the influence of the quantity of paste in concrete, and another is the influence of fluidity of paste affected by a couple of factors.

Mechanical Properties and Durability of Ultra-High Performance Concrete Incorporating Coarse Aggregate

2014 ◽  
Vol 629-630 ◽  
pp. 96-103 ◽  
Author(s):  
Juan Yang ◽  
Gai Fei Peng ◽  
Yu Xin Gao ◽  
Hui Zhang
Keyword(s):  
Compressive Strength ◽  
High Performance ◽  
Coarse Aggregate ◽  
High Performance Concrete ◽  
Fresh Concrete ◽  
Raw Materials ◽  
Autogenous Shrinkage ◽  
Mineral Admixtures ◽  
Ultra High Performance Concrete ◽  
Spalling Failure

Ultra-high performance concrete (UHPC) incorporating coarse aggregate was prepared with common raw materials. Fresh concrete had excellent good workability with slump of 265 mm and slump spread of 673 mm. Compressive strength of UHPC at 56 d reached 150 MPa. However, UHPC exhibited high brittleness in terms of spalling failure which occurred during compression loading.The ratio of splitting tensile strength to compressive strength of about 1/18 and the ratio of flexural strength to compressive strength of about 1/14 at 56 d were also associated with the brittleness of UHPC in this research. Mineral admixtures and fluidity of fresh concrete influenced compressive strength of UHPC significantly. Moreover, UHPC had excellent permeation-related durability but considerable shrinkage. Autogenous shrinkage of UHPC was less than half of free shrinkage, for which the reason is unknown and needs further research.

Preparation of High-Performance Concrete for Adjusting of Possibility of its Usage in Building Practice

2016 ◽  
Vol 722 ◽  
pp. 298-304 ◽  
Author(s):  
Matej Špak
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Fresh Concrete ◽  
Local Source ◽  
Hardened Concrete ◽  
Building Practice ◽  
Source Materials ◽  
Limited Possibility

Technology of High-Performance Concrete (HPC) presents one of advanced concrete technologies. In comparison to common concrete, HPC is characterized by much better qualitative parameters both for fresh and hardened concrete. However, utilization of adequate materials as well as specific processes of both the production and handling of fresh concrete is required to achieve the above standard parameters of concrete. Currently, limited possibility of utilization of local source materials with applicable parameters curtails wider production of HPC within the building practice. Results of experimental approval of HPC properties which was prepared from local aggregates are presented in the paper. Used aggregates have not appropriate parameters for application into HPC on its face. Therefore the achieved results show the potential of its applied utilization.

scholarly journals Effect of KyAl4(Si8-y) O20(OH)4 Calcined Based-Clay on the Microstructure and Mechanical Performances of High-Performance Concrete

Crystals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1152
Author(s):  
David O. Nduka ◽  
Babatunde J. Olawuyi ◽  
Olabosipo I. Fagbenle ◽  
Belén G. Fonteboa
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Cementitious Materials ◽  
Attenuated Total Reflection ◽  
Maximum Temperature ◽  
Microstructural Properties ◽  
Calcined Clay ◽  
X Ray ◽  
Cement Replacement ◽  
Mechanical And Microstructural Properties

The work described in this paper has been performed to determine the potential use of meta-illite (KyAl4(Si8-y) O20(OH)4) calcined clay (MCC) as a supplementary cementitious material (SCM) in a binary Portland cement (PC) for high-performance concrete (HPC) production. To obtain the properties of the cementitious materials, the chemical composition, mineral phases, morphology, calcination efficiency and physical properties were quantitatively analysed using the advanced techniques of X-ray fluorescence (XRF), scanning electron microscopy/energy dispersive X-ray (SEM/EDX), X-ray diffraction (XRD), Fourier transform infrared/attenuated total reflection (FTIR/ATR), thermogravimetric analysis (TGA), laser particle sizing and Brunauer–Emmett–Teller (BET) nitrogen absorption method. The MCC’s effect on the workability and mechanical properties (compressive, splitting tensile and flexural strengths) and microstructure (morphology and crystalline phases) of hardened MCC-based HPCs were determined. The XRF result shows that the oxide composition of MCC confirmed the pozzolanic material requirements with recorded high useful oxides content. At the same time, the SEM image presents particles of broad, solid masses with a wider surface area of irregular shape. The XRD results show that the MCC was majorly an illite-based clay mineral calcined at a maximum temperature of 650 °C, as revealed by the TGA. The MCC addition increases the slump flow of HPCs at 5–15% cement replacement. The MCC incorporation at 10% cement replacement best improved the porosity of HPCs at a later age resulting in increased mechanical and microstructural properties of tested samples. Therefore, it is recommended that MCC addition within 10% cement replacement be adopted for low W/B Class I HPC at no deleterious results on mechanical and microstructural properties of the concrete.

Advances in Research on Influence of Raw Materials on Workability of Fresh Concrete: A Review

2009 ◽  
Vol 405-406 ◽  
pp. 83-88 ◽  
Author(s):  
Gai Fei Peng ◽  
Zhan Qi Guo ◽  
Piet Stroeven ◽  
Ri Gao ◽  
Jiu Feng Zhang
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Fresh Concrete ◽  
Raw Materials ◽  
Experimental Tests ◽  
Solid Particles ◽  
Future Research ◽  
Negative Effect ◽  
The Relationship ◽  
Positive Effect

A literature review was carried out to identify advances in research on workability of fresh concrete via both experimental tests and modeling, especially high performance concrete and self-compacting concrete. As to the relationship between fluidity of concrete and that of paste, future research can be conducted in two aspects, i.e. one is the influence of the quantity of paste in concrete, and another is the influence of fluidity of paste affected by a couple of factors. Most literature proved that the flow of concrete depends both on positive effect and negative effect, the former promote fluidity, such as dispersing, filling and lubricating, and the latter restricts fluidity, such as formation of particle coagulation, an increase of wettable surface of solid particles and mechanical interlock.

Comparison of Multiple Freeze-Thaw Cycles of High-Performance Concrete Test Beams and Concrete Beams Loaded Test

2013 ◽  
Vol 351-352 ◽  
pp. 570-573
Author(s):  
Zhi Qiang Li ◽  
Xian Chun Zheng ◽  
Xiao Hong Cong
Keyword(s):  
Mechanical Properties ◽  
Concrete Structure ◽  
High Performance ◽  
High Performance Concrete ◽  
Concrete Beams ◽  
Reinforced Concrete Structures ◽  
Experimental Basis ◽  
Freeze Thaw ◽  
Thaw Cycle ◽  
Freeze Thaw Cycle

This study focuses on the following: analysis of the basic mechanical properties of freeze-thaw cycles BFRP composite; freeze-thaw cycle on BFRP reinforced concrete structures force performance; provide experimental basis for the the basalt FRP freeze-thaw environment concrete structure andtheoretical support.

Effect of the Expansion Agent on Early-Age Autogenous Shrinkage Stress of Concrete

2013 ◽  
Vol 838-841 ◽  
pp. 564-568
Author(s):  
Pan Xiu Wang
Keyword(s):  
Tensile Strength ◽  
Concrete Structure ◽  
High Performance ◽  
High Performance Concrete ◽  
Autogenous Shrinkage ◽  
Shrinkage Strain ◽  
Shrinkage Stress ◽  
Early Age ◽  
Concrete Cube

Early-age autogenous shrinkage is key problem of high performance concrete. It can cause a lot of early-age cracks in concrete structure and further endanger the permeability and durability. Adding expansion agent can control the early-age autogenous shrinkage strain and reduce the risk of early-age cracks. In this paper, the early-age autogenous shrinkage stress of concrete cube is calculated. The results show that, early-age autogenous shrinkage stress is larger than early-age tensile strength of concrete. So some cracks occur on the surface of concrete structure. By adding expansion agent, the early-age autogenous shrinkage strain and stress both decreases.

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