In this experimental study, the reinforcing effects of graphene oxide (GO) on portland cement paste are investigated. It is discovered that the introduction of 0.03% by weight GO sheets into the cement paste can increase the compressive strength and tensile strength of the cement composite by more than 40% due to the reduction of the pore structure of the cement paste. Moreover, the inclusion of the GO sheets enhances the degree of hydration of the cement paste. However, the workability of the GO-cement composite becomes somewhat reduced. The overall results indicate that GO could be a promising nanofillers for reinforcing the engineering properties of portland cement paste.

Reinforcing effects of graphene oxide on portland cement paste

Effects of carbonation on pore structure and diffusional properties of hydrated cement pastes

Filler cement: The effect of the secondary component on the hydration of Portland cement: Part I. A fine non-hydraulic filler

Supercritical Fluid Chromatography and Extraction

https://hal.archives-ouvertes.fr/hal-01007190/document

Predicting Ca(OH)2 content and chemical shrinkage of hydrating cement pastes using analytical approach

Monitoring Portland cement hydration: Comparison of methods

Gradients of microstructure and diffusion properties in cement paste caused by drying

This paper describes how the curing of concrete is impaired by exposure to drying at early ages. Removing water from the surface layers restricts the binder reactions and pore structure development. High porosity in the surface region will allow the ingress of deleterious agents, which can lead to durability problems. The paper reports results obtained by hydrating a flyash blended cement under drying conditions. Comparisons are made with similar results from a portland cement. Small samples of OPC/pfa (70/30) paste with a water binder ratio of 0.59, initially cured under saturated conditions for 7 days, were exposed at 20 C in a CO(2)-free environment, to various preselected relative humidities. After 28 and 91 days, the extent of reaction and the porosities of the samples were measured by thermogravimetry and methanol adsorption, respectively. Results show the extent of hydration falls when changing from saturated to 70 percent relative humidity (rh) conditions; below this rh, it is virtually constant. From the shape of the TGA curve, it seems that there is little change in the nature of the gel phase. The pozzolanic reaction appeared to cease below 80 percent rh. Total porosity only fell very slightly with increasing relative humidity even after 91 days exposure. Under drying conditions (70 percent rh) the large-diameter porosity was three times greater than large-diameter porosity obtained under saturated conditions. From these tests it is clear that to promote reaction and to effect a decrease in the volume of large pores, the relative humidity must be greater than 95 percent, at least during early-age curing.

David C Killoh

Papers

Monitoring Portland cement hydration: Comparison of methods

Gradients of microstructure and diffusion properties in cement paste caused by drying

Influence of Curing at Different Relative Humidities on the Hydration and Porosity of a Portland/Flyash Cement Paste