Study of self-healing at large ages for a 3D printable ECC material

Abstract

The conventional construction sector is the one that generates CO2 emissions, as well as waste generation. Among all new construction techniques, 3D printing has emerged as an alternative since it is capable of mitigating these inconveniences and has a number of advantages, such as speed of construction and design flexibility. As a result, interest in 3D printing has increased in recent years as a total or partial replacement in the construction sector. Nevertheless, 3D printing has some drawbacks; one of the biggest threats is the generation of cracks or microcracks that appears during the transport or the design of the 3D printed figures. These cracks can cause major structural and durability problems in the final applications.Numerous materials have been developed to meet the requirements of 3D printing. One of the possible developing materials is the ECC (Engineered Cementitious Composites) since it has the capacity for autogenous self-healing, that is, the material presents in its composition the capacity to reduce and heal the possible cracks that are generated. The main goal is to evaluate the self-healing behavior of the 3D printed material (ECC-A3D). This material has the characteristics to achieve structural integrity, reliability, and robustness of 3D printing.In previous stages of research, an ECC-A3D material has been developed having the characteristics to achieve the structural integrity, reliability, and robustness of a 3D printed material. This paper describes the experimental procedure of the evaluation of the self-healing behavior of the ECC-A3D in two different curing conditions (at room temperature, 35 ± 2% RH and 20 ± 2 °C, and curing chamber at 98 ± 2% RH and 20 ± 2 °C). Hardened properties are researched via compressive and flexural for up to 90 days. Meanwhile, the self-healing behavior of ECC is investigated by mechanical recovery test, and absorption and sorptivity tests.This study presents the results of the tests in a hardened state and shows the results that confirm the autogenous healing of ECC material in two different environments.