Test methods of frost resistance of concrete: CIF-Test: Capillary suction, internal damage and freeze thaw test—Reference method and alternative methods A and B

2004 ◽  
Vol 37 (10) ◽  
pp. 743-753 ◽  
Author(s):  
M. J. Setzer ◽  
P. Heine ◽  
S. Kasparek ◽  
S. Palecki ◽  
R. Auberg ◽  
...  
Keyword(s):  
Frost Resistance ◽  
Reference Method ◽  
Test Methods ◽  
Alternative Methods ◽  
Internal Damage ◽  
Capillary Suction ◽  
Freeze Thaw

Deterioration of Concrete Freezing-Thawing in Different Salts Solution

2009 ◽  
Vol 405-406 ◽  
pp. 315-321 ◽  
Author(s):  
Yong Ge ◽  
Wen Cui Yang ◽  
Jie Yuan ◽  
Bao Sheng Zhang ◽  
Ai Ling Xiong
Keyword(s):  
Modulus Of Elasticity ◽  
Dynamic Modulus ◽  
Frost Resistance ◽  
Nacl Solution ◽  
Freezing And Thawing ◽  
Lower Strength ◽  
Internal Damage ◽  
Freeze Thaw ◽  
Concrete Deterioration ◽  
All Solutions

The frost resistance of concrete subjected to 3.5% NaCl solution, 5%, 7%, and 10% Na2SO4 solution and seawater were investigated by quick freeze-thaw test. There were two criteria, the relative dynamic modulus of elasticity (RDME) and the mass of scaling, for evaluating the frost resistance of concrete. The results showed that scaling was the main characteristic of deterioration when concrete subjected to freeze-thaw cycles in 3.5% NaCl solution and seawater, whereas RDME had little change. When freezing and thawing in Na2SO4 solution, concrete failed because of internal damage and surfaces of lower strength concrete specimens appeared local swelling and scaling before failure. Concentration of Na2SO4 solution had influence on frost resistance of concrete: deterioration of concrete in 5% or 7% Na2SO4 solution was severe but slower when the concentration reached to 10%. Entraining air into concrete was the best method to improve the durability of concrete subjected to freeze-thaw cycles in all solutions.

scholarly journals Shape and Size of Particles Scaled from Concrete Surfaces during Salt Frost Testing and Rapid Freeze/thaw in Water

2021 ◽  
Vol 64 (1) ◽  
pp. 53-68
Author(s):  
Marte Beheim Brun ◽  
Andrei Shpak ◽  
Stefan Jacobsen
Keyword(s):  
Particle Size ◽  
Size Distribution ◽  
Test Methods ◽  
Internal Damage ◽  
Flake Thickness ◽  
Freeze Thaw ◽  
Salt Scaling ◽  
Scale Particle ◽  
Size Of Particles ◽  
Air Void

Abstract Thickness (T), Length (L), Width (W) and size distribution of scaled concrete particles in frost testing were measured. T (mm) increases with particle size surprisingly similarly for different concrete qualities and frost test methods. 2T/(L+W) reduces as function of size and is lowest for the largest particles of the salt scaling test: 0.1 – 0.15 but increases if large aggregate particles scale. Particle size distributions from salt frost testing peak for particles of 1-2 mm. The particles are flakier compared to particles from freeze/thaw in water which also have flatter size distribution no matter type of concrete or degree of damage. Scaling in water is not so efficiently reduced by air voids despite protecting very efficiently against internal damage and scaling in salt frost testing. Comparisons with T predicted by the glue spall model (≈3/4 × ice thickness) and the air void dependent (≈3× critical air void spacing) model proposed by Fagerlund are difficult due to the size dependent flake thickness. Image analysis could well describe shape. Further studies of concrete flake thickness scaled at varying thickness of ice layers are proposed.

CIF-Test-Capillary suction, internal damage and freeze thaw test

2001 ◽  
Vol 34 (9) ◽  
pp. 515-525 ◽  
Author(s):  
M. J. Setzer ◽  
R. Auberg ◽  
S. Kasparek ◽  
S. Palecki ◽  
P. Heine
Keyword(s):  
Internal Damage ◽  
Capillary Suction ◽  
Freeze Thaw

Studies the Properties of Polyaspartic Polyurea Coated Concrete under Coaction of Salt Fog and Freeze-Thaw

2012 ◽  
Vol 455-456 ◽  
pp. 781-785
Author(s):  
Ping Lu ◽  
Xin Mao Li ◽  
Xue Qiang Ma ◽  
Wei Bo Huang
Keyword(s):  
Elastic Modulus ◽  
Frost Resistance ◽  
Dynamic Elastic Modulus ◽  
Freeze Thaw ◽  
Decrease Rate ◽  
Thaw Cycle ◽  
Freeze Thaw Cycle ◽  
Salt Fog

. This paper mainly studied the properties of PAE polyurea coated concrete under coactions of salt fog and freeze-thaw. After exposed salt fog conditions for 200d, T3, B2, F2 and TM four coated concrete relative dynamic elastic modulus have small changes, but different coated concrete variation amplitude is different. T3 coated concrete after 100 times of freeze-thaw cycle the relative dynamic elastic modulus began to drop, 200 times freeze-thaw cycle ends, relative dynamic elastic modulus variation is the largest, decrease rate is 95%, TM concrete during 200 times freeze-thaw cycle, relative dynamic elastic modulus almost no change, B2 concrete and F2 concrete the extent of change between coating T3 and TM. After 300 times the freeze-thaw cycle coated concrete didn't appear freeze-thaw damage phenomenon. Four kinds of coating concrete relative dynamic elastic modulus variation by large to small order: T3 coated concrete > B2 coated concrete >F2 coated concrete > TM coated concrete, concrete with the same 200d rule. Frost resistance order, by contrast, TM coated concrete > B2 coated concrete > F2 coated concrete > T3 coated concrete.

Optimization Research of Mix Proportion of Frost Resistance Construction of Concrete Based on the MATLAB Language

2014 ◽  
Vol 584-586 ◽  
pp. 1917-1921
Author(s):  
Jun Jie Zhang ◽  
Rui Hong Shao ◽  
Xiang Yi Meng
Keyword(s):  
Compressive Strength ◽  
Objective Function ◽  
Frost Resistance ◽  
Unit Volume ◽  
Influence Factors ◽  
Multi Objective Optimization ◽  
Cold Region ◽  
Freeze Thaw ◽  
Performance Indexes ◽  
Mix Proportion

Analyze the influence factors of mix proportion affecting concrete freeze-thaw damage. Use the five main performance indexes of the concrete, which are compressive strength, strength of extension, impermeability grade, and frost resistance grade and per unit volume cost concrete, as the objective function of multi-objective optimization equation. Invoke the fgoalattain function in the MATLAB Optimization Toolbox to solve. The optimized parameters of mix proportion of frost resistance construction of unit concrete in cold region are: concrete 1532.6kg, water 910kg, sand 5510.6kg, 5-20mm cobblestone 3747.2kg、20-40mm cobblestone 3658.6kg、40-80mm cobblestone 4733.5kg、80-150mm cobblestone 4738.1kg, and the dosage of water reducing agent is 7.3kg.

scholarly journals Timing of Peripheral Blood Stem Cell Yield: Comparison of Alternative Methods with the Classic Method for CD34+Cell Determination

2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
I. Fatorova ◽  
M. Blaha ◽  
M. Lanska ◽  
D. Vokurkova ◽  
V. Rezacova ◽  
...  
Keyword(s):  
Stem Cells ◽  
Peripheral Blood ◽  
Reference Method ◽  
Roc Curves ◽  
Alternative Methods ◽  
Optimal Timing ◽  
Hematopoietic Tissue ◽  
Peripheral Blood Stem Cells ◽  
Hematopoietic Stem ◽  
Blood Stem Cells

Hematopoietic stem cells (HSCs), still represent a certain mystery in biology, have a unique property of dividing into equal cells and repopulating the hematopoietic tissue. This potential enables their use in transplantation treatments. The quality of the HSC grafts for transplantation is evaluated by flow cytometric determination of the CD34+cells, which enables optimal timing of the first apheresis and the acquisition of maximal yield of the peripheral blood stem cells (PBSCs). To identify a more efficient method for evaluating CD34+cells, we compared the following alternative methods with the reference method: hematopoietic progenitor cells (HPC) enumeration (using the Sysmex XE-2100 analyser), detection of CD133+cells, and quantification of aldehyde dehydrogenase activity in the PBSCs. 266 aphereses (84 patients) were evaluated. In the preapheretic blood, the new methods produced data that were in agreement with the reference method. The ROC curves have shown that for the first-day apheresis target, the optimal predictive cut-off value was 0.032 cells/mL for the HPC method (sensitivity 73.4%, specificity 69.3%). HPC method exhibited a definite practical superiority as compared to other methods tested. HPC enumeration could serve as a supplementary method for the optimal timing of the first apheresis; it is simple, rapid, and cheap.

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