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...

Alkali Activated Concrete (AAC) is an alternative kind of concrete that uses fly ash as a total replacement of Portland cement. Fly ash combined with alkaline solution and cured at high temperature reacts to form a binder. Four point bending tests on two full scale beams made with AAC are described in this paper. Companion small material specimens were also casted with the aim of properly chara...

This study evaluated the sealing ability of apical plugs made of white and gray MTA-Angelus and white Portland cement placed via the root canal and having different thicknesses (2, 5 and 7 mm). Ninety extracted human single-rooted teeth were instrumented using a size 40 K-file to standardize the foraminal opening by the stepback technique. The teeth were assigned to 3 groups (n=30), according t...

Conventional concrete technology generates significant amounts of CO2, NOx and SOx (greenhouse gases linked with global warming) through the combustion of fossil fuels to process and transport concrete components as well as the calcination of limestone required to create portland cement. Furthermore, the mining and processing of conventional concrete components damages ecosystems and exhausts n...