Autogenous Self-Healing Capacity of Early-Age Ultra-High-Performance Fiber-Reinforced Concrete

Estefania Cuenca,Pedro Serna

doi:10.3390/su13063061

Estefania Cuenca, Pedro Serna

Open Access

https://doi.org/10.3390/su13063061

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Journal: Sustainability	Publication Date: Mar 11, 2021
Citations: 16	License type: CC BY 4.0

Affiliation: Universitat Politècnica de València

Abstract

This paper analyzes the autogenous self-healing capacity of early-age Ultra-High-Performance Fiber-Reinforced concretes (UHPFRCs) by measuring the crack closure and the possible mechanical recovery on healed specimens. The main parameters considered in this research were the healing exposure conditions (humidity chamber, immersion in tap water, immersion in seawater and heat curing) and the precracking levels (microcracks and macrocracks). For the microcrack level, four-point bending tests were performed on prismatic specimens (100 × 100 × 500 mm3) obtaining a multiple cracking pattern characterized by crack widths ranged from 10 to 20 µm. Whereas for the macrocrack level (behavior after crack localization), splitting tests were carried out on notched cubic specimens (100 × 100 × 100 mm3) obtaining crack widths of up to 0.4 mm. For both precracking levels, specimens were precracked at two days and were cured for one month in the mentioned exposure conditions. Healing products were analyzed on the specimen surface and also inside the cracks; to this purpose, their microstructure was analyzed by means of SEM and EDS analyses. The results have shown that the highest crack closure values were obtained for the heat-cured specimens and for the specimens immersed in water (tap water and seawater) whereas the less efficient condition was the humidity chamber.

Highlights

IntroductionPublisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations
Specimens were casted and cured; secondly, specimens were precracked to create a controlled damage in the specimens; thirdly, specimens were exposed to different environments to promote healing of cracks; and self-sealing and self-healing ability were quantified in terms of crack closure and mechanical recovery, respectively
Concrete was cured into the mold for 24 h and after demolding cylinders were cured for 28 days in a humidity chamber (T = 20 ◦ C, relative humidhumidity (RH) = 100%)

Summary

Introduction

Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. Sustainability is becoming more relevant every day in the field of construction [1]

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Results