Forming Anisotropic Crystal Composites: Assessing the Mechanical Translation of Gel Network Anisotropy to Calcite Crystal Form

The promise of crystal composites with direction-specific properties is an attractive prospect for diverse applications; however, synthetic strategies for realizing such composites remain elusive. Here, we demonstrate that anisotropic agarose gel networks can mechanically "mold" calcite crystal growth, yielding anisotropically structured,...

An Improved Test for Generating Rapid, Accurate, and Reliable Crack Permeability Data for Cementitious Materials

Presented is a modified test for generating crack permeability data for cementitious materials. Single-parallel cracks were generated in mortar specimens. The width of the cracks was analysed through stereomicroscope and computer tomography, and the water permeability of the cracks was determined. Reduction factors and crack flow models were...

Volume fraction, thickness, and permeability of the sealing layer in microbial self-healing concrete containing biogranules

Autonomous repair systems in construction materials have become a promising alternative to current unsustainable and labor-intensive maintenance methods. Biomineralization is a popular route that has been applied to enhance the self-healing capacity of concrete. Various axenic microbial cultures were coupled with protective carriers, and their...

ESEM-BSE coupled with rapid nano-scratching for micro-physicochemical analysis of marine exposed concrete

Ordinary Portland cement (OPC) mortar specimens submerged in sea-water were analysed through environmental scanning electron microscopy (ESEM) in back scattered electron (BSE) mode and nano-scratching. Results from both sets of analysis show the presence of distinct phases associated with aragonite, brucite and cement paste. Phases associated...

Microbially mediated carbonation of marine alkaline minerals: Potential for concrete crack healing

Concrete constructions in the marine environment suffer from chemical attack of sea salts which can induce damage to both the concrete matrix and embedded steel reinforcement. For example, ingress of sulfate and chloride ions can respectively result in detrimental ettringite formation and enhanced corrosion of the steel rebars. The first...

Bacteria-based self-healing concrete for application in the marine environment

Marine concrete structures are exposed to one of the most hostile of natural environments. Many physical and chemical phenomena are usually interdependent and mutually reinforcing in the deterioration of marine exposed concrete: expansion and microcracking due to physical effects increases concrete permeability paving the way for harmful...

Microbially mediated carbonation of marine alkaline minerals: Potential for concrete crack healing

Concrete constructions in the marine environment suffer from chemical attack of sea salts which can induce damage to both the concrete matrix and embedded steel reinforcement. For example, ingress of sulfate and chloride ions can respectively result in detrimental ettringite formation and enhanced corrosion of the steel rebars. The first...

Bacteria-based self-healing concrete for application in the marine environment

Marine concrete structures are exposed to one of the most hostile of natural environments. Many physical and chemical phenomena are usually interdependent and mutually reinforcing in the deterioration of marine exposed concrete: expansion and microcracking due to physical effects increases concrete permeability paving the way for harmful...