The moisture and drying resistance of a novel cement based nanocomposite, polymer intercalated/exfoliated (PIE) cement, is analyzed. The effects of the post-processing treatment procedure and the nanofiller content are discussed. The experimental results indicate that the flexure strength of the PIE cement is higher than that of ordinary Portland cements by more than an order of magnitude, and ...

1 Calcium Silicate Hydrates in cementitious materials 1.1 Sustainability Challenge .... ..................... 1.2 Cement Chemistry Notation A Primer ............ 1.3 Hydration of Portland Cement ...................... 1.3.1 Initial and slow reaction periods . . . . . . . . . . . . . 1.3.2 Nucleation & Growth of C-S-H . . . . . . . . . . . . . 1.3.3 Open Questions in Cement Hydration . . . . . ....

To improve the corrosion protection provided to prestressing strands, anti-bleed grouts are used to fill voids in post-tensioning ducts that result from bleeding and shrinkage of older portland cement grouts. Environmental differences caused by exposing the strands to dissimilar grouts, however, have the potential to cause rapid corrosion. Portland cement grout, gypsum grout, and four commercia...

AIM To compare the ability of Portland cement and mineral trioxide aggregate (MTA) to prevent coronal leakage through repaired furcal perforations in molar teeth. METHODOLOGY The pulp chambers of 36 human mandibular molar teeth were accessed and the root canal orifices were located. The roots were horizontally sectioned in the middle third. Composite resin was used to fill the root canal orif...

In this research the effects of adding silica and alumina nanoparticles on flow ability and compressive strength of cementitious composites based on Portland cement were investigated. In the first stage, the rheological behavior of different samples containing nanosilica, nanoalumina and polypropylene, polyvinyl alcohol and polyethylene fibers were evaluated. With increasing of nanoparticles in...

BACKGROUND It has been suggested that dust exposure causes airway inflammation among cement factory workers. However, there is limited information on the mechanisms of this effect. We explored any associations between total dust exposure and fractional exhaled nitric oxide (FENO) as a marker of airway eosinophilic inflammation among cement production workers in Tanzania. We also examined possib...

SUMMARY: Exposure to cement dust has been linked to lung function impairment. However, there are few such studies in Nigeria. The main aim of this study was to assess the post-work Peak Expiratory Flow Rate (PEFR) of workers in a cement company. Sixty workers in a cement factory were randomly selected; thirty were regarded as workers exposed to cement dust and the remaining as unexposed workers...

a r t i c l e i n f o A hydration kinetics model for Portland cement is formulated based on thermodynamics of multiphase porous media. The mechanism of cement hydration is discussed based on literature review. The model is then developed considering the effects of chemical composition and fineness of cement, water–cement ratio, curing temperature and applied pressure. The ultimate degree of hyd...