Nanoindentation of Cement Pastes and Its Numerical Modeling

Author(s):  
Jiří Němeček ◽  
Petr Kabele ◽  
Zdeněk Bittnar
Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 5024
Author(s):  
Alexandre Pierre ◽  
Daniel Weger ◽  
Arnaud Perrot ◽  
Dirk Lowke

The 3D printing of concrete has now entered a new era and a transformation of the construction sector is expected to reshape fabrication with concrete. This work focuses on the selective paste intrusion method, which consists of bonding dry particles of aggregate with a cement paste. This innovative technique could lead to the production of very precise component for specific applications. The main obstacle to tackle in order to reach a high shape accuracy of high mechanical performances of 3D printing elements by selectively activating the material is the control of the distribution of the cement paste through the particle bed. With the aim to better understand the path followed by the solution as it penetrates a cut-section of the granular packing, two-dimensional numerical modeling is carried out using Comsol software. A phase-field method combined with a continuous visco-plastic model has been used to study the influence of the average grain diameter, the contact angle, and the rheological properties of cement pastes on the penetration depth. We compare the numerical modeling results to existing experimental results from 3D experiments and a one-dimensional analytical model. We then highlight that the proposed numerical approach is reliable to predict the final penetration of the cement pastes.


2007 ◽  
Author(s):  
T. Campbell ◽  
B. de Sonneville ◽  
L. Benedet ◽  
D. J. W. Walstra ◽  
C. W. Finkl

Author(s):  
D.S. Rakisheva ◽  
◽  
B.G. Mukanova ◽  
I.N. Modin ◽  
◽  
...  

Numerical modeling of the problem of dam monitoring by the Electrical Resistivity Tomography method is carried out. The mathematical model is based on integral equations with a partial Fourier transform with respect to one spatial variable. It is assumed that the measurement line is located across the dam longitude. To approximate the shape of the dam surface, the Radial Basic Functions method is applied. The influence of locations of the water-dam, dam-basement, basement-leakage boundaries with respect to the sounding installation, which is partially placed under the headwater, is studied. Numerical modeling is carried out for the following varied parameters: 1) water level at the headwater; 2) the height of the leak; 3) the depth of the leak; 4) position of the supply electrode; 5) water level and leaks positions are changing simultaneously. Modeling results are presented in the form of apparent resistivity curves, as it is customary in geophysical practice.


2015 ◽  
Vol 35 ◽  
pp. 232-235 ◽  
Author(s):  
Leonardo Piccinini ◽  
Paolo Fabbri ◽  
Marco Pola ◽  
Enrico Marcolongo ◽  
Alessia Rosignoli

2016 ◽  
Vol 41 ◽  
pp. 10-13 ◽  
Author(s):  
Luca Alberti ◽  
Martino Cantone ◽  
Silvia Lombi ◽  
Alessandra Piana

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