A survey was conducted to ascertain the variations practiced in powder/liquid (P/L) ratio of Glass Ionomer Cement (GIC) used as restorative and luting material in dental clinics of Karachi. It has been observed that in the use of GIC brands, 33% (Fuji 2) and 36% (Gold Label 2) of the dentists, did not follow the recommended P/L ratios for restorative purposes. Similarly, 67% (Fuji 1) and 29% (G...

Thermal conductivity plays a significant role in controlling thermal cracking of cement-based materials. In this study, the cement paste at an early age was measured by hot plate method. The test results showed that decreased with increase water/cement ratio and curing age. Meanwhile, multiphase model for proposed used to study influence saturation temperature on paste. To determine parameters ...

This study examined the stress-strain behavior of 10 calcium hydroxide (Ca(OH)2)-activated Hwangtoh concrete mixes. The volumetric ratio of the coarse aggregate (V agg) and the water-to-binder (W/B) ratio were selected as the main test variables. Two W/B ratios (25% and 40%) were used and the value of V agg varied between 0% and 40.0%, and 0% and 46.5% for W/B ratios of 25% and 40%, respectivel...

This paper proposes the mixing design of concrete having modified sulfur-coated aggregate (MSCA) to enhance the durability of Portland cement concrete. The mechanical properties and durability of the proposed MSCA concrete were evaluated experimentally. Melting-modified sulfur was mixed with aggregate in order to coat the aggregate surface at a speed of 20 rpm for 120 s. The MSCA with modified ...

Ceramic waste is most commonly produce from ceramic industry, this waste is in the form of pest and hard form, pest waste is known as the filter waste or slurry waste, which is produced at the end of polishing and finishing of ceramic tiles. The paper discuss that ceramic slurry waste powder is replaced by cement in concrete. Concrete grade M25 was made by replacing by 0% to 30% of Ordinary Por...

The purpose of this study was to develop an alpha-tricalcium phosphate (alpha-TCP) cement which transforms to hydroxyapatite (HAP) in a relatively short period. We used calcium and phosphate solutions as the liquid phase for the alpha-TCP cement. The alpha-TCP powder was first mixed with CaCl2 solution, and then mixed with NaH2PO4 or Na2HPO3 solution for a total powder/liquid ratio of 1.8. The ...

Setting properties of bone substitutes are improved using an injectable system. The injectable bone graft substitutes can be molded to the shape of the bone cavity and set in situ when injected. Such system is useful for surgical operation. The powder part of the injectable bone cement is included of β-tricalcium phosphate, calcium carbonate, and dicalcium phosphate and the liquid part contains...

This study aims at determining the effect of the cement composition and mortar age on the optimum content of sulphates using maximization of compressive strength as a criterion. Extensive experimentation has been performed to achieve this purpose by utilizing four cement types and measuring the strength at ages ranging from 2 days up to 63 months. Strength is correlated with the ratio of sulpha...

The influence of silicon doping on calcium phosphate cement were explored in this work. α-TCP and Si-α-TCP were prepared by solid state reaction employing “Mg-free” CaHPO 4 , CaCO 3 and CaSiO 3 as precursors. It was possible to obtain TCP powders with low contents of β phase as contaminant. Cement liquid phase was an aqueous solution containing 2.5 wt. (%) of Na 2 HPO 4 and 1.5 wt. (%) of citri...