EXPOSURE TEST AND NUMERICAL SIMULATION ON THE INFLUENCE OF OUTDOOR WEATHER ACTION ON THE DRYING SHRINKAGE OF CONCRETE

2021 ◽  
Vol 77 (4) ◽  
pp. 134-149
Author(s):  
Keisuke MINOWA ◽  
Takumi SHIMOMURA ◽  
Yuichiro KAWABATA ◽  
Takashi FUJII ◽  
Jun TOMIYAMA
Keyword(s):  
Numerical Simulation ◽  
Drying Shrinkage ◽  
Exposure Test

Numerical Simulation of The Drying Shrinkage Process of Concrete

2011 ◽  
Vol 194-196 ◽  
pp. 913-918
Author(s):  
Yong Cun Zhang ◽  
Qing Ning Li
Keyword(s):  
Numerical Simulation ◽  
Surface Chemistry ◽  
Mechanical Model ◽  
Water Surface ◽  
Drying Shrinkage ◽  
Shrinkage Strain ◽  
Volume Shrinkage ◽  
Shrinkage Process ◽  
Capillary Pore

Based on surface chemistry, the force status of capillary pores of concrete is analyzed and the mechanical model of a single capillary pore in concrete is built with use of ANSYS, a sort of software for analysis and calculation. Then drying shrinkage strain of concrete is simulated. With the continuous evaporation of water, when the radius of concave water surface drop to a certain value, the corresponding shrinkage strain of concrete can be approximately calculated out. Finally the curve of gradually increasing concrete volume-shrinkage strain versus the decreasing radius of concave water surface is described. The existed errors of this simulation are analyzed,and some suggestion for improvements is given.

Numerical Simulation on Chloride Ions Diffusion in Concrete

2011 ◽  
Vol 261-263 ◽  
pp. 348-351 ◽  
Author(s):  
Qing Wang ◽  
Gang Xu ◽  
Jun Wei
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Concentration Distribution ◽  
Chloride Concentration ◽  
Simulation Method ◽  
Chloride Ions ◽  
Test Results ◽  
Exposure Test ◽  
Modified Model ◽  
Chloride Ions Diffusion

Allowing for the analogy between ions diffusion and heat transfer, the numerical simulation on chloride ions diffusion in concrete can be realized following the thermal analysis module in the large general FEA software ANSYS, by reasonable equivalent of parameters. It is based on the modified model for Fick’s second diffusion law, taking the factors of temperature, humidity and time etc. into account. Hereby, the numerical simulation method is established for predicting the chloride concentration distribution with time in concrete, testified by the coastal exposure test. The test results confirm the efficiency and feasibility of the method.

Modified gach technique vs critical point drying: Shrinkage analysis for SEM

1987 ◽  
Vol 45 ◽  
pp. 954-955
Author(s):  
B. Thompson ◽  
N. Sculov ◽  
R.E. Crang
Keyword(s):  
Critical Point ◽  
Calf Serum ◽  
Drying Shrinkage ◽  
Specimen Preparation ◽  
Cell Shrinkage ◽  
Whole Cells ◽  
Critical Point Drying ◽  
Prepared Material ◽  
Inverted Microscope ◽  
Phosphate Buffered Saline

The use of co-polymerized glutaraldehyde-carbohydrazide (GACH) was proposed for specimen preparation in scanning electron microscopy (SEM) as a means of avoiding dehydration in organic solvents, and to provide dimensionally stable biological specimens through a process of air-drying. It has been assumed that shrinkage of specimens prepared by the GACH technique should be less than that of conventionally-prepared material by critical point drying (CPD). In a previous study, Bell has reported significant shrinkage of whole cells for SEM. This report compares cell shrinkage in GACH and CPD preparations.Fibroblasts from newborn rats were grown on collagen-coated glass cover-slips (with alpha numeric grids etched onto the surface of the coverslips) in Eagle's minimum essential medium + 10% fetal calf serum for 7 d. (3). Using an inverted microscope with phase-contrast optics, micrographs were taken of the cultures in their live state and 1 h. after fixation with 2.5% glutaraldehyde in Dulbecco's phosphate buffered saline (Figs. 1 and 3).

Environmental microscopy of capillary stress-induced strain behavior in ambient-pressure aerogels

1996 ◽  
Vol 54 ◽  
pp. 850-851
Author(s):  
Sudeep M. Rao ◽  
Joshua Samuel ◽  
Sai S. Prakash ◽  
C. Jeffrey Brinker
Keyword(s):  
Silica Aerogel ◽  
Ambient Pressure ◽  
Drying Shrinkage ◽  
Pore Filling ◽  
Silica Network ◽  
Strain Behavior ◽  
Partially Saturated ◽  
Capillary Stress ◽  
Wetting Liquid ◽  
Aerogel Films

Ambient pressure silica aerogel thin films have recently been prepared by exploiting reversible drying shrinkage caused by derivatization of the internal gel surface. Aerogels have porosities of upto 99.9% and due to the small size of the pores (few nanometers), large capillary stresses are produced in gels that are partially saturated with a wetting liquid. As a result of these capillary stresses, the flexible silica network undergoes strain which has been observed using environmental microscopy. This technique allows variation of the equilibrium vapor pressure and temperature, and a simultaneous monitoring of the deformation of the unconstrained film thickness. We have observed >600% deformation during the pore-filling and pore-emptying cycles. In this presentation, we discuss the unique stress-strain behavior of these films.Ref.: Sai S. Prakash, C. Jeffrey Brinker, Alan J. Hurd & Sudeep M. Rao, "Silica aerogel films prepared at ambient pressure by using surface derivatization to induce reversible drying shrinkage", Nature. Vol. 374, 30 March, 1995, 439-443.

Water uptake by substituted amylose tablets: experimentation and numerical simulation

2009 ◽  
Vol 00 (00) ◽  
pp. 090904073309027-8
Author(s):  
H.W. Wang ◽  
S. Kyriacos ◽  
L. Cartilier
Keyword(s):  
Numerical Simulation ◽  
Water Uptake
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