Numerical modeling of microcrack behavior in encapsulation-based self-healing concrete under uniaxial tension

다국어 초록 (Multilingual Abstract)

We investigated microcrack behavior in encapsulation-based self-healing concrete subjected to uniaxial tension by using finite element analysis. 3D circular capsule with particular shell thickness embedded in the mortar matrix samples was modeled. To represent potential cracks, zero thickness cohesive elements with bi-linear traction-separation law were pre-inserted into the initially generated meshes. Effects of fracture strength variation among the mortar matrix, the capsule, and the interface between them on crack nucleation, initiation, and propagation were investigated. The results showed that the mismatch among fracture strengths of the capsule, the mortar matrix, and the interface of them has a significant influence on crack nucleation, initiation, and propagation. Using similar fracture strength between capsule and mortar matrix, together with high fracture strength of their interface, will initiate a crack from the mortar matrix and then propagate directly into the capsule. This condition is the most favorable case in the capsule-based self-healing concrete since a capsule contained with a healing agent will likely fracture. Thus, the self-healing process in the concrete can be achieved effectively. In addition, the interface with lower fracture strength than the mortar matrix and the capsule strengths will initiate a crack from the interface and then leave the capsule intact. Hence, the self-healing mechanism could not be achieved. These results will become some valuable assets for the experimentalists to assist in their experimental works.

참고문헌 (Reference)

• 1 L. M. Mauludin, "The effects of interfacial strength on fractured microcapsule" 13 (13): 353-363, 2019
• 2 B. Erzar, "Tensile strength of dried mortar over a wide range of strain rate" (1) : 603-609, 2009
• 3 F. Gilabert, "Stress concentrations and bonding strength in encapsulation-based selfhealing materials" 67 : 28-41, 2015
• 4 B. Šavija, "Simulation-aided design of tubular polymeric capsules for self-healing concrete" 10 (10): 10-, 2017
• 5 P. Areias, "Quasi-static crack propagation in plane and plate structures using set-valued traction-separation laws" 74 (74): 475-505, 2008
• 6 Y. L. Gui, "Modelling the dynamic failure of brittle rocks using a hybrid continuum-discrete element method with a mixed-mode cohesive fracture model" 87 : 146-155, 2016
• 7 L. M. Mauludin, "Modeling of self-healing concrete : A review" 5 : 526-539, 2019
• 8 L. M. Mauludin, "Interaction between matrix crack and circular capsule under uniaxial tension in encapsulationbased self-healing concrete" 3 (3): 181-189, 2018
• 9 L. Chen, "Extended finite element method with edgebased strain smoothing(ESm-XFEM)for linear elastic crack growth" 209 : 250-265, 2012
• 10 B. A. Budiman, "Evaluation of interfacial strength between fiber and matrix based on cohesive zone modeling" 90 : 211-217, 2016
• 11 B. Hilloulin, "Design of polymeric capsules for self-healing concrete" 55 : 298-307, 2015
• 12 C. Oucif, "Continuum damage-healing and super healing mechanics in brittle materials : A state-of-the-art review" 8 (8): 2350-, 2018
• 13 L. M. Mauludin, "Computational modeling of fracture in encapsulation-based self-healing concrete using cohesive elements" 196 : 63-75, 2018
• 14 S. A. Ponnusami, "Cohesive-zone modelling of crack nucleation and propagation in particulate composites" 149 : 170-190, 2015
• 15 E. Gruyaert, "Capsules with evolving brittleness to resist the preparation of self-healing concrete" 66 (66): 092-, 2016
• 16 C. Zhang, "A dynamic XFEM formulation for crack identification" 12 (12): 427-448, 2016