This research investigates changes in the nanostructure and the nanoscale local mechanical properties of cement paste with microand nano-modifiers. Silica fume and multiwall carbon nanotubes (MWCNTs) were used as microand nano-modifiers. An effective method of dispersing CNTs in cement matrix was developed. A detailed study on the effects of CNTs concentration and aspect ratio on the fracture p...

In spite of not being legally accepted in most countries, mixed recycled aggregates (MRA) could be a suitable raw material for concrete manufacturing. The aims of this research were as follows: (i) to analyze the effect of the replacement ratio of natural coarse aggregates with MRA, the amount of ceramic particles in MRA, and the amount of cement, on the mechanical and physical properties of a ...

The uniaxial compression response of manufactured sand mortars proportioned using different water-cement ratio and sand-cement ratio is examined. Pore structure parameters such as porosity, threshold diameter, mean diameter, and total amounts of macropores, as well as shape and size of micropores are quantified by using mercury intrusion porosimetry (MIP) technique. Test results indicate that s...

The rheological properties of blended cement-based materials depend strongly on mixture proportions and the characteristics of the components. In this study, design of experiments is used to investigate the influence of three variables (cement particle size distribution (PSD), fly ash PSD, and ratio of fly ash to cement) at each of four levels on the yield stress and viscosity of blended pastes...

The utilization of cemented tailings/paste backfill (CPB) by the mining industry is becoming increasingly important. However, it has been difficult to analyze the economic usage of CPB for fine unclassified tailings. Therefore, the physical and chemical properties of fine unclassified tailings, sampled from the Sijiaying Mine, were first analyzed in this study. After this, active excitation of ...

An understanding of how the cementing technique influences cement penetration is important for surgeons to plan and conduct hip resurfacing procedures. Therefore the aim of this study is to determine the influence of the following parameters on cement penetration: use of pulse lavage, type of cement, and the standing period of the cement. Nine fresh frozen paired whole cadaver femora were used ...

In cement-based materials porosity plays an important role in determining their mechanical and transport properties. This paper describes an improved low–cost embeddable miniature NMR sensor capable of non-destructively measuring evaporable water loss and porosity refinement in low and high water-to-cement ratio cement-based materials. The sensor consists of two NdFeB magnets having their North...

Use of Vitremer Core Buildup/Restorative Cement (3M Dental Products Division) as a luting cement for orthodontic bands and space maintainers was described in 1994. For use as a luting agent, the restorative cement is mixed with a slightly lower powder liquid ratio so the blend is more fluid than one used for a dental restoration. A chief advantage of using Vitremer Restorative Cement for luting...

OBJECTIVES No data are currently available on the prevalence and characteristics of functional dyspepsia among cement workers. Given the potential impact of dyspepsia on work performance, whether its prevalence is increased among workers exposed to cement dust was evaluated. METHODS Altogether 420 cement workers were enrolled in the study. According to the individual exposure levels to cement...