High performance concrete (HPC) requires a low water-to-cementitious materials mass ratio (w/cm), often with the inclusion of supplemental cementitious materials such as silica fume in the mixture, thus necessitating the use of a superplasticizer. Because of the low w/cm and rapid reaction at early ages, proper curing from the earliest time possible is very essential in HPC. Internal curing has...

Cement-based materials are widely used in the construction of civil infrastructure systems. However, normal wear-and-tear and extreme loading can result in the damage and deterioration of such important civil structures. In this study, a novel approach to the detection of cracks in fiber reinforced cementitious composites (FRCC) is proposed. The approach is based upon the electrical properties ...

The paper proposes a combined application of composite theory and Powers’ model for microstructural development for the estimation of the diffusion coefficient as a function of the moisture content of a defect-free cementitious material. Measurements of chloride diffusion in mortar samples (440 kg/m rapid-hardening Portland cement, w/c = 0.5, maturity minimum 6 months) stored at 65% and 85% RH,...

Hydrated lime is a historic material currently used in conservation. It hardens slowly by carbonation slowing construction however, supplementary cementitious materials accelerate hardening enhancing strength. Hydrated-lime mortars with rice husk ash–RHA-; ground granulated blastfurnace slag–GGBSand increasing amounts of two aggregates were studied. Increasing aggregate lowered strength as inte...

The exemplary mechanical performance and durability of ultra-high performance concrete (UHPC) has led to its rapid emergence as an advanced cementitious material. The uncharacteristically high mechanical strength and ductility of UHPC makes it a promising potential material for defense structures which may be subject to highly dynamic loads like impact or blast. However, the mechanical response...

Cracking is one of the most severe problems facing the concrete industry worldwide. Of critical importance is the drastic decline of durability associated with these cracks, and the resulting cost of repair or replacement of concrete structures. This research examines the effect of crack width and crack frequency upon the durability of reinforced mortar, quantified by water permeability. Crack ...

Nuclear magnetic resonance (NMR) relaxation experimentation is an effective technique for probing the dynamics of proton spins in porous media, but interpretation requires the application of appropriate spin-diffusion models. Molecular dynamics (MD) simulations of porous silicate-based systems containing a quasi-two-dimensional water-filled pore are presented. The MD simulations suggest that th...