Freeze-thaw durability of high-performance concrete – Mechanism of water uptake and internal damage

2006 ◽  
Author(s):  
Susanne Palecki
Keyword(s):  
Water Uptake ◽  
High Performance ◽  
High Performance Concrete ◽  
Internal Damage ◽  
Freeze Thaw

Resistance of Adhesive Bonding of Ultra-High Performance Concrete to Hygrothermal, Corrosive, and Freeze-Thaw Cycling Environments

2009 ◽  
Vol 6 (9) ◽  
pp. 101990 ◽  
Author(s):  
R. Krelaus ◽  
G. Wisner ◽  
S. Freisinger-Schadow ◽  
M. Schmidt ◽  
S. Böhm ◽  
...  
Keyword(s):  
High Performance ◽  
Adhesive Bonding ◽  
High Performance Concrete ◽  
Ultra High Performance Concrete ◽  
Freeze Thaw

Material Properties of Ultra - High Performance Concrete in Extreme Conditions

2016 ◽  
Vol 711 ◽  
pp. 157-162 ◽  
Author(s):  
David Citek ◽  
Milan Rydval ◽  
Stanislav Rehacek ◽  
Jiří Kolísko
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Material Properties ◽  
High Performance ◽  
High Performance Concrete ◽  
High Strength ◽  
Accurate Information ◽  
Extreme Conditions ◽  
Ultra High Performance Concrete ◽  
Freeze Thaw

The Ultra High Performance Concrete (UHPC) is a very promising material suitable for application in special structures. However, the knowledge of performance of this relatively new material is rather limited. The exceptional mechanical properties of UHPC allow for a modification of the design rules, which are applicable in ordinary or high strength concrete. This paper deals in more detail with impact of thermal stress on bond properties between prestressing strands and UHPC and an influence of high temperature to final material properties of different UHPC mixtures. Specimens in the first experimental part were subjected to the cycling freeze-thaw testing. The relationship between bond behavior of both type of material (UHPC and ordinary concrete) and effect of cycling freeze-thaw tests was investigated. The second part of experimental work was focused on mechanical properties of UHPC exposure to the high temperature (Tmax = 200°C to Tmax = 1000°C). Tested mechanical properties were compressive and flexural strengths, the fracture properties will be presented in the next paper. The obtained experimental data serve as a basis for further systematic experimental verification and more accurate information about the significantly higher material properties of UHP(FR)C and its behavior in extreme conditions.

Fire-Damage or Freeze-Thaw of Strengthening Concrete Using Ultra High Performance Concrete

2009 ◽  
Vol 79-82 ◽  
pp. 2047-2050 ◽  
Author(s):  
Min Gin Lee ◽  
Yi Shuo Huang
Keyword(s):  
High Temperature ◽  
High Performance ◽  
High Performance Concrete ◽  
Fire Damage ◽  
Ultra High Performance Concrete ◽  
Freeze Thaw ◽  
Concrete Members ◽  
Repair Materials ◽  
Environmental Durability ◽  
Temperature Exposure

There are some reinforced concrete structures exposed to severe environmental conditions might require maintenance or strengthening. Many of these severe circumstances are the result of extreme climate conditions such as low temperature, freeze–thaw action, fire attack, and exposure to deicing salts. Because of this, the environmental durability of both the repair materials and methods used in rehabilitation applications are of utmost importance. A small fire can reach 250°C, while a common blaze can easily produce temperatures of around 800°C. In major conflagrations the temperature can even reach 1100°C. At this level, the heat affects most materials, provoking the spontaneous combustion of some of them and affecting the resistance of others. However, very little research has been performed in evaluating the environmental durability of strengthening materials for concrete members. Very little work has been done on the effects of freeze–thaw cycling on bonding and repair materials. In this study, ultra high performance concrete (UHPC) was used to investigate the effect of strengthening concrete members by fire-damage test or freeze-thaw test. The results show that the mechanical properties of UHPC possess high strength, toughness, and freeze-thaw resistance. The CFRP (carbon fiber reinforced plates) wrapping specimens exposed at 300 °C showed totally failure with the deterioration of the adhesive. The UHPC with bonding 10 mm thickness specimens exposed at 400 °C and duration of 1 hour still in good shape. The UHPC with 1-cm or 2-cm thickness on strengthening concrete members could be obtained specific retrofit effects. The performance of UHPC specimens is better than those of CFRP wrapping specimens during high temperature exposure. The results of slant shear tests show that the bond strength of PC/PC, UHPC/PC and UHPC/UHPC decreased significantly after 600 freeze–thaw cycles or high temperature exposure.

Les effets des caractéristiques du réseau de bulles d'air, du type de mûrissement, du truellage de surface et de la fumée de silice sur la résistance à l'écaillage d'un béton à haute performance

1996 ◽  
Vol 23 (6) ◽  
pp. 1260-1271
Author(s):  
Richard Gagné ◽  
Yvon Latreille ◽  
Jacques Marchand
Keyword(s):  
Silica Fume ◽  
High Performance ◽  
High Performance Concrete ◽  
Surface Finishing ◽  
Air Bubbles ◽  
Concrete Durability ◽  
Freeze Thaw ◽  
Spacing Factor ◽  
Entrained Air ◽  
Scaling Resistance

In Canada, high-performance concretes (HPCs) are increasingly used in construction and repair, particularly for its durability, which is distinctly superior compared with ordinary concrete. The current tendency is to provide for a spacing factor of air bubbles lower than 230 μm in all HPCs that are subjected to freeze–thaw cycles. This choice is basically the outcome of an ongoing controversy as to the necessity of providing a good network of entrained air bubbles to protect HPCs against freeze–thaw cycles. In the future, the optimal use of HPC will depend, among other factors, on a better understanding of minimal requirements regarding the characteristics of air voids to ensure a good behavior of HPCs under freeze–thaw cycles. The results of the investigation reported herein show that a spacing factor lower than approximately 500 μm can be sufficient to ensure a good resistance of HPCs to scaling. It is also shown that surface trawling, slump, and set-retarding agents have only secondary effects on the scaling resistance of HPCs. Silica fume and membrane curing have allowed to improve significantly the scaling resistance of the HPCs under investigation. Key words: high-performance concrete, durability, scaling, set-retarding agent, silica fume, surface finishing, curing, pumping, entrained air, spacing factor.

Influence of Curing Age and Water-Binder Ratio on Chloride Permeability under Freeze-Thaw and Load

2013 ◽  
Vol 405-408 ◽  
pp. 2610-2615
Author(s):  
Lei Hong ◽  
Run Min Duo
Keyword(s):  
Diffusion Coefficients ◽  
High Performance ◽  
High Performance Concrete ◽  
Chloride Diffusion ◽  
Chloride Permeability ◽  
Freeze Thaw ◽  
Thaw Cycle ◽  
Binder Ratio ◽  
Water Binder Ratio ◽  
Curing Age

The chloride diffusion coefficients of different water-binder ratio high performance concrete (HPC) subjected to different one-way loads，freeze-thaw cycles and different standard curing ages were measured by electro-migration (RCM) tests and the results were analyzed. The test results indicate that with the increase of one-way load, its influence on the chloride permeability of different water-binder ratio HPC rises in the same proportion. The influence of the curing age on the chloride permeability of HPC will decrease with the reduction of the water-binder ratio of HPC. Under the same freeze-thaw cycle conditions, the relationships between chloride diffusion coefficients of different water-binder ratio HPC and curing ages are nearly suitable to power function.

Rehydration of Ultra High Performance Concrete

2014 ◽  
Vol 897 ◽  
pp. 275-279 ◽  
Author(s):  
Ulrich Diederichs ◽  
Iris Marquardt ◽  
Vít Petranek
Keyword(s):  
Water Vapor ◽  
Water Uptake ◽  
High Performance ◽  
High Performance Concrete ◽  
High Strength ◽  
Porous System ◽  
Ultra High Performance Concrete ◽  
Micro Cracks ◽  
Maximum Temperatures ◽  
Subsequent Storage

Ultra High Performance Concrete (UHPC) and High Strength Concrete (USC) are because of the high density of their matrices very susceptible to spalling during fire exposure. By aid of a heat treatment with maximum temperatures of about 450°C a network of capillaries and micro cracks could be formed, which leads like a porous medium to a relief of water vapor already at harmless low pressures and could prevent the materials from spalling. In the framework of the presented study on UHPC some orientating tests have been performed to obtain knowledge concerning alterations of the microstructure during thermal treatment at 150°C, 250°C, 350°C and 450°C and the subsequent storage in air with 100% relative humidity at 20°C as to allow water uptake and rehydration. The tests have shown that by aid of the said treatment generation of a respective porous system was achieved, which remained open for the transport of water vapor at high temperatures, also after water uptake and rehydration of the dehydrated cementitious matrix. However further studies are needed to get information about effects of the treatments on the mechanical properties and the durability of members.

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.

scholarly journals The Influence of Ambient Temperature on High Performance Concrete Properties

Materials ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 4646
Author(s):  
Alina Kaleta-Jurowska ◽  
Krystian Jurowski
Keyword(s):  
Compressive Strength ◽  
High Performance ◽  
High Performance Concrete ◽  
Curing Temperature ◽  
Hardened Concrete ◽  
Water Penetration ◽  
Ambient Temperatures ◽  
Freeze Thaw ◽  
Air Content ◽  
Flow Table

This paper presents the results of tests on high performance concrete (HPC) prepared and cured at various ambient temperatures, ranging from 12 °C to 30 °C (the compressive strength and concrete mix density were also tested at 40 °C). Special attention was paid to maintaining the assumed temperature of the mixture components during its preparation and maintaining the assumed curing temperature. The properties of a fresh concrete mixture (consistency, air content, density) and properties of hardened concrete (density, water absorption, depth of water penetration under pressure, compressive strength, and freeze–thaw durability of hardened concrete) were studied. It has been shown that increased temperature (30 °C) has a significant effect on loss of workability. The studies used the concrete slump test, the flow table test, and the Vebe test. A decrease in the slump and flow diameter and an increase in the Vebe time were observed. It has been shown that an increase in concrete curing temperature causes an increase in early compressive strength. After 3 days of curing, compared with concrete curing at 20 °C, an 18% increase in compressive strength was observed at 40 °C, while concrete curing at 12 °C had a compressive strength which was 11% lower. An increase in temperature lowers the compressive strength after a period longer than 28 days. After two years of curing, concrete curing at 12 °C achieved a compressive strength 13% higher than that of concrete curing at 40 °C. Freeze–thaw performance tests of HPC in the presence of NaCl demonstrated that this concrete showed high freeze–thaw resistance and de-icing materials (surface scaling of this concrete is minimal) regardless of the temperature of the curing process, from 12 °C to 30 °C.

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