introduction: the aim of this study was to compare the cytotoxicity of proroot mta (pmta), root mta (rmta) and portland cement (pc) on human gingival fibroblasts (hgfs). materials and methods: the extracts of the test materials were placed close to human gingival fibroblasts (hgfs) within 96-well plates. cellular viability was assessed using mtt assay in different intervals (freshly mixed, 4, 2...

Hydraulic activity refers to a property most familiar when discussing hydraulic cement such as ordinary portland cement (OPC). ASTM C125-15a defines hydraulic cement as “a cement that sets and hardens by chemical reaction with water and is capable of doing so under water.” That is, hydraulic cements, including SCMs that have hydraulic properties, react with water to harden, and that hardening p...

Cement is the basic material for making concrete that can be used as a hydraulic binder. There are various types of cement including OPC and PCC cement. The problem now there no technical data reference in determining proportion mixture. Examples obtained from same factory. namely PT. Semen Tonasa, South Sulawesi with an amount 78.96 kg each type From results laboratory tests, it was found on c...

Abstract: This work was designed to investigate the simultaneous effect of both water-to-cement (W/C) and polymer-to-cement(P/C) ratios on flexural strength of type V Portland cement pastes containing polyvinyl alcohol. The obtained resultsconfirmed the strong effect of W/C-ratio on the effectiveness of the added polymer so that there exist optimum valuesfor both W/C and P/C-ratios. Pastes prep...

Superplasticizers are a class of anionic polymer dispersants used to inhibit aggregation in hydraulic cement, lowering the yield stress of cement pastes to improve workability and reduce water requirements. The plant-derived biopolymer lignin is commonly used as a low-cost/low-performance plasticizer, but attempts to improve its effects on cement rheology through copolymerization with synthetic...

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...