heavy metals, e.g. cd and pb emit and release into the environment during cement production and are deposited into soils. this research was carried out to determine the concentration and spatial distribution of trace elements in top soils around the kurdistan cement factory, west of iran in order to evaluate the effect of cement factory on the environment. twenty-four soil samples were collecte...

In this research, 210 concrete cube specimens (15cm) were made replacing 0, 5, 10, 15, 20, 25, 30, 35, 40, 50, and 60 percent of slag powder from Isfahan Steel Mill for cement. The control specimens were made with 350 kg/m3 cement content and the water cement ratio in all specimens was 0.51. The Slump value and compressive strength of concrete specimens in 7, 28 and 90 days were obtained and th...

A Biodegradable artificial bone with inter-connective pores was prepared using a self-setting apatite/collagen composite cement as a cell scaffold for bone regenerative medicine, and investigated as to biocompatibility by X-ray computed tomography (CT) after its implantation into rats. Blocks (APN, APC and ACC) of apatite cement, apatite cement with continuous holes, and apatite/collagen compos...

Hart, Stephanie, "Characterization and restoration of historic Rosendale cement mortars for the purpose of restoration" (2012). ABSTRACT Mortar was a very common building material in today's historic sites. Before Portland cement was manufactured at a global level, Rosendale cement was commonly used in these mortars. Over time, these mortars in historic sites have begun to break down and wear a...

The present Experimental investigation is to study the Mechanical Properties of the Fly ash concrete reinforced with steel fibers. The concrete composite comprises of steel fibers in different percentages and partial replacement of cement in different proportions. Steel fibers varied from 0%, 0.5%, 1% and 1.5% by weight of cement and replacement of fly ash varied from 0%, 10%, 20%, 30% and 40% ...

Herein, the performance of graphene oxide (GO) in improving mechanical properties and subsequently reducing the permeability of cement composites used in concrete pavement, is studied. A polycarboxylate superplasticizer was used to improve the dispersion of GO flakes in the cement. The mechanical strength of graphene-cement nanocomposites containing 0.1–2 wt% GO and 0.5 wt% superplasticizer was...

Dosima fascicularis is the only barnacle which can drift autonomously at the water surface with a foam-like cement float. The cement secreted by the animal contains numerous gas-filled cells of different size. When several individuals share one float, their size and not their number is crucial for the production of both volume and mass of the float. The gas content within the cells of the foam ...

In this article 5-25 V% of a sol-gel bioglass fiber was incorporated into calcium phosphate bone cement to improve its mechanical properties. Compressive strength, work of fracture, elastic modulus and setting time of the cement were investigated as well as phase changes occurring during soaking the specimens in simulated body fluid (SBF). The cement microstructure was also observed by scanning...

Tetracalcium phosphate nanomonetite cements have been prepared by reaction milling of tetracalcium phosphate with orthophosphoric acid ethanol solution, which was modified with different water content. The presence of nanomonetite phase significantly reduced the pH value of cement pastes during hardening. The fast transformation of reactants in cement powder mixtures was observed during hardeni...

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...