ED WHELESS Whittier, California The Commerce Refuse to Energy Facility (CREF) is a nominal 370 tpd mass fired facility located in Com­ merce, California. After extensive testing of the ash, over 4 years of plant operation, a treatment system was developed and pilot tested which utilizes Portland cement to control the leaching of heavy metals. This paper describes the design and operation of the...

Metakaolin based geopolymers are presented in many studies as an alternative to normal Portland cement. Previous studies have focused on their chemical and mechanical properties, their microstructures and their potential uses, but very few on their rheological behaviour. Our work highlights the main differences that exist between geopolymer and Portland cement. These materials behave as Newtoni...

Physical and chemical characteristics of ashes formed at burning oil shale at temperatures 500, 600, 700, 800, 900 and 1030 °C were studied. Standard procedures were used to determine both pozzolanic activity and binding parameters. The most suitable characteristics were provided with oil shale ash formed at 700 °C. Ashes (15 and 30%) were added to ordinary Portland cement. The optimum pozzolan...

Synopsis-In this research, possible usage of EAF dust on cement is investigated. Therefore, effects of addition of different percentages of EAF dust on the most important properties of cement such as hydration heat, water coefficient, viscosity, initial and final setting times, strength development and leachability of heavy metals were studied. Results showed that EAF dust alters the characteri...

Cement dust exposure is associated with increased respiratory impairment. As the major occupational hazard in the cement production industry is cement particles, our aim was to more thoroughly examine the acute effects of occupational exposure to cement dust on the respiratory system. A cross-shift study was conducted in a cement factory in Iran. 100 high exposed workers from production and pac...

Study was carried out to assess the impact of cement dust on some selected plant species around industrial area. Deposition effect of cement dust on pigmentation was studied in Azadirachta indica, Pongamia pinnata, Delonix regia, Polyalthia longifolia and Ficus religiosa. Sampling was done about 500 meter distance difference from the cement industry and measurements were taken for all the plant...

It is difficult to obtain high quality samples of natural material covering a range of densities and degree of cementation, so study on the sample preparation techniques with similar mechanical properties of natural samples are very important. Experiments were carried out to study the effects of cementation of different materials on the mechanical properties of calcareous sand, e.g., the effect...

OBJECTIVE The purpose of this study was to investigate the pulpal response of dogs' teeth after pulpotomy and direct pulp protection with MTA Angelus, ProRoot, Portland cement and white Portland cement. STUDY DESIGN Seventy-six teeth were treated with these materials. One hundred twenty days after treatment, the animals were sacrificed and the specimens removed and prepared for histological a...

Abstract Cement mortar is a binding material that made of cement, sand and water. In general, mixes are raw materials. However, using materials in producing leads to many environmental economic issues. One the most common solutions reduce these issues replacing by waste and/or by-product materials; especially cement. The aim this research explore characteristics after partially Ordinary Portlan...

Portland cement has been analyzed and compared to mineral trioxide aggregate (MTA) because of their chemical similarity. The possibility of using this material as a less expensive alternative to MTA in dental practice should be considered. In view of this, the present study compared the components of a Portland cement (Votoran) to two commercial brands of MTA (Pro-Root and MTA-Angelus). Twelve ...