The influence of cement fineness on early-age properties of cement-based materials is investigated using a variety of experimental techniques. Properties that are critical to the earlyage performance of these materials are tested, including heat release, temperature rise, chemical shrinkage and autogenous deformation. Measurements of these properties for two cements of widely different fineness...

The microstructure and interfacial transition zone characteristics of Portland cement mortars prepared with a polynaphthalene sulfate (PNS) superplasticizer at relatively high dosages (0.8%, 1.5% by mass of cement) and varying sand-to-cement ratios (0.5, 1.0, 1.5) were investigated, using AC impedance spectroscopy, mercury intrusion porosimetry, helium pycnometry and two electrical conductance ...

Approximately, 50 to 70 percent of hydration products in hydrated cement paste are polymorphisms of C-S-H gel. It is highly influential in the final properties of hardened cement paste. Distinguishing C-S-H nano-structure significantly leads to determine its macro scale ensemble properties. This paper is dealt with nano-scale modeling. To achieve this, the most important C-S-H compounds, with a...

Synopsis: In terms of workability of cement based materials, ettringite formation is of major importance. Thus, the interaction between polycarboxylate-ether based superplasticizers (PCE) and various pure cement clinker and hydrate phases is investigated by means of rheological, adsorption and zeta potential measurements. Microstructural analysis of fresh pastes is carried out using cryo-micros...

AIM The aim of this study was to evaluate the diffusion ability of ions through dentinal tubules of different nonalcoholic calcium hydroxide-containing herbal pastes and compare it with the calcium hydroxide paste prepared with saline. MATERIALS AND METHODS A total of 36 single-rooted premolar teeth were used in this study. The tooth crowns were removed and the root canals were prepared. Depe...

The present study focuses on exploring the effects of reactivity and degree dispersion BaCO 3 additions in manufacture sulfate-resistant OPC cements. A new electrochemical deposition method is attempted to effectively disperse particles (studying two different materials with particle size: D 50 = 11.45 2.37 μm) cement enhance their favour sulfate immobilisation form BaSO 4 . barium carbonate ad...

Portland cement is the one of the main ingredients in the manufacture of many building materials include concrete composites. The phase composition of hydration products is controlled by means of XRD and DTA/TG analysis. Observations of phase changes and microstructure of maturing cement pastes can also be observed using scanning electron microscopy (SEM) techniques combined with chemical analy...