scholarly journals Studies on the Influence of Drying Shrinkage Test Procedure, Specimen Geometry, and Boundary Conditions on Free Shrinkage

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Bruce Menu ◽  
Marc Jolin ◽  
Benoit Bissonnette
Keyword(s):  
Boundary Conditions ◽  
Test Procedure ◽  
Drying Shrinkage ◽  
Experimental Results ◽  
Specimen Geometry ◽  
Ring Test ◽  
Test Results ◽  
Free Shrinkage ◽  
Free Ring ◽  
The Impact

Although considerable progress has been made in enhancing the use and interpretation of free ring shrinkage test, little is known about the impact of the test procedure, the specimen geometry, the surface area-to-volume (S/V) ratio exposed to drying, and the boundary conditions (sealing configuration) on the measured shrinkage. This paper highlights recent findings illustrating the influence of the test procedure, the S/V ratio exposed to drying, the geometry of specimen, and the boundary conditions. A series of experimental results are presented from free shrinkage on ring test specimens to illustrate that the test procedure can significantly influence the measured free shrinkage. A second series of experimental results are presented from specimens with different geometries and S/V ratio exposed to drying to illustrate that drying shrinkage is dependent on both the specimen geometry and the surface exposed to drying. Test results further show that, even for the same S/V ratio exposed to drying, shrinkage is strongly dependent on the specimen’s geometry and boundary conditions.

Fluid-Dynamic Loading on a Tilted Rectangular Cylinder Near a Solid Wall

2006 ◽  
Author(s):  
Stefano Malavasi ◽  
Emanuele Zappa
Keyword(s):  
Boundary Conditions ◽  
Strouhal Number ◽  
Vortex Shedding ◽  
Solid Wall ◽  
Large Body ◽  
Experimental Results ◽  
Different Boundary Conditions ◽  
Force Coefficients ◽  
Rectangular Cylinder ◽  
The Impact

We investigate the impact of different boundary conditions on the flow field developing around a tilted rectangular cylinder. We are mainly interested in analyzing the changes in force coefficients and in the vortex shedding Strouhal number due to the proximity of the cylinder to a bottom plate (placed at various distances from the cylinder) at different angles of attack. The angle of attack ranges between −30° and +30° and the cylinder elevation above the bottom wall is varied between almost zero and 200 mm. The effects of the different boundary conditions on the vortex shedding phenomenon are investigated by considering the Strouhal number of the vortex shedding as the key controlling parameter. The experimental results mimicking the unbounded conditions (relative large elevation of the cylinder above the solid wall) are in close agreement with those already found in literature. On the contrary, remarkable differences occur when the elevation of the cylinder is decreased. A large body of experimental results is related to the small elevation conditions at different attack angles, where the presence of the wall has a non-negligible effect on the behavior of the force coefficients and Strouhal number of the vortex shedding.

scholarly journals Uncertainty Factors and Their Effects in Experimental Results of Composite Structures

2020 ◽  
Vol 9 (3) ◽  
pp. 2731-2735
Keyword(s):  
Composite Structures ◽  
Experimental Results ◽  
Void Content ◽  
Test Results ◽  
Compression Tests ◽  
Certainty Factor ◽  
Uncertainty Factors ◽  
Potential Impact ◽  
Major Factors ◽  
The Impact

Uncertainty factors can be considered as major factors influencing experimental results. This article reviews the potential impact of uncertainty in manufacturing composite structures. It also describes the impact of the following factors on the testing process: Void content, curing time, tester calibration read error, interlinear bond, and mixed striping. Test specimens of hexagonal tubes were selected for testing. Test specimens are tested under axial compression tests. Observation and test results showed that the un-certainty factor significantly influenced the final result. Furthermore, the possible reasons for these findings and their implications were discussed.

Study on Vertical Earth Pressure of Slab Culvert under High Embankment

2012 ◽  
Vol 256-259 ◽  
pp. 1898-1902 ◽  
Author(s):  
Bao Kuan Ning ◽  
He Fan ◽  
Lei Gong ◽  
Guo Qing Liu
Keyword(s):  
Numerical Simulation ◽  
Boundary Conditions ◽  
Field Test ◽  
Structural Design ◽  
Earth Pressure ◽  
Test Results ◽  
Soil Pressure ◽  
Vertical Earth Pressure ◽  
The Impact ◽  
Good Agreement

With the increasing of embankment culvert engineering applications, there has been due in part to the structural design is too conservative and not economic or select unreasonable structural form, leading to the phenomenon of cracking or even collapse of the culvert structure, and the phenomenon has seriously affected the normal use of the highway. In this paper, the numerical simulation of vertical earth pressure distribution on different structural forms of embankment on culverts, to discuss the impact of boundary conditions, fill height, the thickness of the culvert culverts vertical earth pressure. Combined with Heda highway a culvert covert field test results and numerical simulation results were compared and analyzed. The results show that the numerical simulation and field test results in good agreement with the culvert structure in the form of vertical earth pressure of the embankment culverts have a greater impact; the structure of different forms of the culvert in the upper soil pressure is significantly different. In addition, analysis of the impact of boundary conditions, filling height of culvert vertical earth pressure values. The results can reference for the study of the structural design of the embankment culverts security.

Experimental Study on the Early Shrinkage-cracking Property of the Polypropylene Fibe Concrete

2011 ◽  
Vol 236-238 ◽  
pp. 2259-2263
Author(s):  
Xian Song Xie
Keyword(s):  
Experimental Study ◽  
Autogenous Shrinkage ◽  
Drying Shrinkage ◽  
Early Age ◽  
Polypropylene Fibers ◽  
Free Shrinkage ◽  
Shrinkage Cracking ◽  
Plastic Shrinkage ◽  
Hardening Process ◽  
The Impact

Early shrinkage of concrete includes plastic shrinkage before the final setting, drying shrinkage during hardening process and autogenous shrinkage. Concrete drying shrinkage which is caused by evaporation is a major factor for the concrete volume change. By ring constrained test and free shrinkage CONCEN test, this paper studies the impact of polypropylene fibers on the shrinkage properties of concrete at the early age. The test shows that the polypropylene fibers can significantly reduce the early shrinkage of concrete, the best content of C30 concrete should be 0.9kg/m3.

Experimental Study on Drying Shrinkage Performance of Solid Concrete Bricks Made from Recycled Coarse Aggregate

2013 ◽  
Vol 753-755 ◽  
pp. 762-770 ◽  
Author(s):  
Xi Xi He ◽  
Tao Zhang
Keyword(s):  
Moisture Content ◽  
Water Absorption ◽  
Coarse Aggregate ◽  
Drying Shrinkage ◽  
Recycled Aggregate ◽  
Test Results ◽  
Replacement Rate ◽  
Recycled Coarse Aggregate ◽  
The Impact ◽  
The Relationship

Solid recycled coarse aggregate concrete bricks were produced by QTY4-40 brick machine with strength grades of MU15-MU30. Recycled aggregate replacement rate was up to 100%. Water absorption and moisture content were tested. Two methods were taken to test the drying shrinkage. The impact of recycled aggregate replacement rate and curing period on the drying shrinkage rate, water absorption, moisture content, density was analyzed, and the relationship between them was presented. The results indicate that recycled aggregate can increase the shrinkage of solid concrete brick. The shrinkage of recycled solid concrete bricks' (fully substitute) is larger than ordinary concrete bricks' by 1.6-2 times. Water reducer is helpful to improve the water retention and decrease the shrinkage of brick. One of the test results of shrinkage got by the methods recommended in relevant specification is smaller.

Experimental Investigation into the Impact of Polypropylene Fibers and SRA on the Early Crack Resistance of Concrete

2011 ◽  
Vol 194-196 ◽  
pp. 858-864 ◽  
Author(s):  
Xian Song Xie ◽  
Fang Tian ◽  
Yi Hong Hong
Keyword(s):  
Experimental Investigation ◽  
Volume Change ◽  
Autogenous Shrinkage ◽  
Drying Shrinkage ◽  
Early Age ◽  
Polypropylene Fibers ◽  
Free Shrinkage ◽  
Plastic Shrinkage ◽  
Hardening Process ◽  
The Impact

Early shrinkage of concrete includes plastic shrinkage before the final setting, drying shrinkage during hardening process and autogenous shrinkage. Concrete drying shrinkage which is caused by evaporation is a major factor for the concrete volume change. By ring constrained test and free shrinkage TONCEN test, this paper studies the impact of polypropylene fibers and SRA on the shrinkage properties of concrete at the early age. The test shows that the polypropylene fibers and SRA can significantly reduce the early shrinkage of concrete, and SRA works more evidently than polypropylene fibers.

Model estimates of the results of diabetes patients using modern glucometers with tri-color technology for displaying test results

2019 ◽  
pp. 81-89
Author(s):  
Larisa Dmitrievna Popovich ◽  
Svetlana Valentinovna Svetlichnaya ◽  
Aleksandr Alekseevich Moiseev
Keyword(s):  
Diabetes Mellitus ◽  
Type 2 Diabetes ◽  
Type 1 Diabetes ◽  
Economic Benefits ◽  
Test Results ◽  
Self Monitoring ◽  
Patients With Diabetes ◽  
The Impact

Diabetes – a disease in which the effect of the treatment substantially depends on the patient. Known a study showed that the use of glucometers with the technology of three-color display of test results facilitates self-monitoring of blood sugar and leads to a decrease in glycated hemoglobin (HbAlc). Purpose of the study: to modeling the impact of using of a glucometer with a color-coded display on the clinical outcomes of diabetes mellitus and calculating, the potential economic benefits of reducing the hospitalization rate of patients with diabetes. Material and methods. Based on data from two studies (O. Schnell et al. and M. Baxter et al.) simulation of the reduction in the number of complications with the use of a glucometer with a color indication. In a study by O. Schnell et al. a decrease of HbA1c by 0.69 percent is shown when using the considered type of glucometers, which was the basis of the model. Results. In the model, the use of a glucometer with a color-coded display for type 1 diabetes led to a decrease in the total number of complications by 9.2 thousand over 5 years per a cohort of 40 thousand patients with different initial levels of HbA1c. In a cohort of 40 thousand patients with type 2 diabetes, the simulated number of prevented complications was 1.7 thousand over 5 years. When extrapolating these data to all patients with diabetes included in the federal register of diabetes mellitus (FRD), the number of prevented complications was 55.4 thousand cases for type 1 diabetes and 67.1 thousand cases for type 2 diabetes. The possible economic effect from the use of the device by all patients with a diagnosis of diabetes, which are included in the FRD, estimated at 1.5 billion rubles for a cohort of patients with type 1 diabetes and 5.3 billion rubles for patients with type 2 diabetes. Conclusion. Improving the effectiveness of self-monitoring, which is the result of the use of glucometers with color indicators, can potentially significantly reduce the incidence of complications in diabetes and thereby provide significant economic benefits to society.

The Impact of Cash Mobs in the Vote with the Wallet Game: Experimental Results

2016 ◽  
Author(s):  
Leonardo Becchetti ◽  
Maurizio Fiaschetti ◽  
Francesco Salustri
Keyword(s):  
Experimental Results ◽  
The Impact
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