From waste to self-healing concrete: the missing PHA-link

Self-healing concrete has attracted increasing attention of researchers and industry over the last decades. Given the brittle nature and the relatively low tensile strength of concrete, the occurrence of cracks is an almost unavoidable phenomenon affecting (reinforced) concrete structures. Cracks allow harmful agents present in the environment...

Assessment of Functional Performance, Self-Healing Properties and Degradation Resistance of Poly-Lactic Acid and Polyhydroxyalkanoates Composites

In this study, the applicability of two bacteria-based healing agents (e.g., poly-lactic acid and polyhydroxyalkanoate) in blast furnace slag cement (BFSC) mortar has been assessed. An experimental campaign on the functional properties, self-healing capacity, freezing–thawing and carbonation resistance has been conducted in comparison with plain...

From waste to self-healing concrete: A proof-of-concept of a new application for polyhydroxyalkanoate

Polyhydroxyalkanoate (PHA) production is a promising opportunity to recover organic carbon from waste streams. However, widespread application of waste-derived PHA as biodegradable plastic is restricted by expensive purification steps, high quality requirements, and a fierce competition with the conventional plastic market. To overcome these...

Influence of self-healing induced by polylactic-acid and alkanoates-derivates precursors on transport properties and chloride penetration resistance of sound and cracked mortar specimens

The possible beneficial impact of self-healing on chloride transport through cracks has been assessed for two bacteria-based self-healing mortar mixtures in comparison with Ordinary Portland cement mortar. Intact self-healing specimens featured lower chloride transport coefficients thanks to a denser microstructure and to the formation of a...

Assessment of the self-healing capacity of cementitious materials through active thin sections

Since self-healing of cementitious materials can theoretically improve the service-life of concrete structures, it has gathered significant attention from both researchers and industry during the last two decades. Many researchers have proposed different methods to assess and quantify the self-healing capacity (i.e. the ability of...

Self-healing capacity of mortars with added-in bio-plastic bacteria-based agents: Characterization and quantification through micro-scale techniques

In this study, a novel non-toxic, biodegradable bacteria-based healing agent known as alkanoate derivatives (AKD) derived from wastewater was investigated for its self-healing efficiency of the mortar specimens in comparison to the already-developed healing agents made of lactic acid derivatives (PLA). Mortar with different percentages of...

On the Applicability of a Precursor Derived from Organic Waste Streams for Bacteria-Based Self-Healing Concrete

Bacteria-based self-healing concrete has the ability to heal cracks due to the bacterial conversion of incorporated organic compounds into calcium carbonate. Precipitates seal the cracks, theoretically increasing the service life of constructions. The aim of this paper is to propose a precursor for bacteria-based self-healing concrete derived...

Chemo-physico-mechanical properties of the interface zone between bacterial PLA self-healing capsules and cement paste

In this study, the interface between different types of bacteria-embedded self-healing polylactic acid capsules (PLA) and cement paste is investigated. Particularly, the changes in microstructure and mechanical properties of the interface with respect to bulk cement paste were studied. First, nanoindentation was performed to obtain maps of...