Computational microstructure modeling of transverse thermal behavior in cementitious composites filled with randomly dispersed natural fibers coated by functionally graded interphase

2021 ◽  
Vol 180 ◽  
pp. 121772
Author(s):  
Mengfei Han ◽  
Hui Wang
Keyword(s):  
Thermal Behavior ◽  
Natural Fibers ◽  
Functionally Graded ◽  
Cementitious Composites ◽  
Microstructure Modeling

scholarly journals Influence of Carbon Nanotubes on Phase Composition, Thermal and Post-Heating Behavior of Cementitious Composites

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 850
Author(s):  
Mohammad R. Irshidat ◽  
Nasser Al-Nuaimi ◽  
Mohamed Rabie
Keyword(s):  
Carbon Nanotubes ◽  
Phase Composition ◽  
Thermal Behavior ◽  
Elevated Temperatures ◽  
Positive Impact ◽  
Cementitious Composites ◽  
Hydration Products ◽  
Heat Treated ◽  
C Decomposition ◽  
Compressive And Flexural Strengths

This paper experimentally investigates the influence of carbon nanotubes (CNTs) on phase composition, microstructure deterioration, thermal behavior, and residual mechanical strengths of cementitious composites exposed to elevated temperatures. Cement mortars with small dosages of CNTs, 0.05% and 0.2% by weight of cement, were prepared and then heated at 25 °C, 150 °C, 200 °C, 450 °C, and 600 °C for two hours before being tested. The results show positive impact of the CNTs on the hydration process of cement mortar at room temperature and at higher temperatures up to 200 °C. Decomposition of the hydration products is obvious at 450 °C, whereas sever deterioration in the microstructure occurs at 600 °C. The nano reinforcement and bridging effect of the CNTs are obvious up to 450 °C. Thermal behavior characterization shows that CNTs incorporation enhances the thermal conductivity of the unheated and heat-treated mortar specimens. The decomposition of the hydration products needs more heat in the presence of CNTs. Finally, presence of CNTs significantly enhances the residual compressive and flexural strengths of heated mortar specimens for all studied temperatures.

scholarly journals A Numerical Study on 3D Printed Cementitious Composites Mixes Subjected to Axial Compression

Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 6882
Author(s):  
Hanqiu Liu ◽  
King-James Idala Egbe ◽  
Haipeng Wang ◽  
Ali Matin Nazar ◽  
Pengcheng Jiao ◽  
...  
Keyword(s):  
Numerical Study ◽  
Functionally Graded ◽  
Cementitious Composites ◽  
Recent Developments ◽  
3D Printed ◽  
Material Volume ◽  
Functionally Graded Structure ◽  
Good Agreement ◽  
Layer Position

Aptly enabled by recent developments in additive manufacturing technology, the concept of functionally grading some cementitious composites to improve structural compression forms is warranted. In this work, existing concrete models available in Abaqus Finite Element (FE) packages are utilized to simulate the performance of some cementitious composites numerically and apply them to functional grading using the multi-layer approach. If yielding good agreement with the experimental results, two-layer and three-layer models case combinations are developed to study the role of layer position and volume. The optimal and sub-optimal performance of the multi-layer concrete configurations based on compressive strength and sustained strains are assessed. The results of the models suggest that layer volume and position influence the performance of multi-layer concrete. It is observed that when there exists a substantial difference in material strengths between the concrete mixes that make up the various layers of a functionally graded structure, the influence of position and of material volume are significant in a two-layer configuration. In contrast, in a three-layer configuration, layer position is of minimal effect, and volume has a significant effect only if two of the three layers are made from the same material. Thus, a multilayered design approach to compression structures can significantly improve strength and strain performance. Finally, application scenarios on some structural compression forms are shown, and their future trajectory is discussed.

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