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Assessment of Pollution Potentialities of some Portland Cement
HH Ibrahim, UA Birnin-Yauri, C Muhammad, A Umar
Nigerian Journal of Basic and Applied Sciences , 2012,
Abstract: Chemical analysis of some Portland cement commonly used in Nigeria was carried out. All the cement studies were found to be good for concrete work especially where no special property is required. The concentration levels of heavy metals in all the cement samples were above the tolerance limit and therefore need to be regulated.
Comparative histological study between MTA and Portland cement  [PDF]
Cristina de Jesus REISS-ARAúJO,Kércya da Silva PAIM,Marcelo de Azevedo RIOS,Diana Santana de ALBUQUERQUE
RSBO , 2008,
Abstract: Introduction: Several studies have demonstrated the effectiveness ofMTA as a promising material in Dentistry. There is a possibility thatthe Portland cement may provide the same results of MTA due to thesimilar composition of both materials. Objective: comparing the MTAand Portland cement by means of histological observation. Materialand methods: Two groups of five wistar rats (Rattus novergicus) eachwere submitted to surgery at the filtrum area for insertion of apolyethylene tube containing MTA (left side) and Portland cement(rightside). After flap closure, the animals were placed in isolation and two different periods (2 and 12 weeks) were selected to sacrifice the animals.Blocks were obtained from the animals, stored in 10% formalin solution and submitted to histological preparation. All blocks were observed under a light microscope. Results: The results showed that the MTA yielded a less intense histological reaction than the Portland cement in 2-week period. In the 12-week period, the histological results were very similar for both cements. Conclusion: Utilization of the Portland cement in Dentistry can be considered.
MTA versus Portland cement: review of literature  [PDF]
Naiana Viana Viola,Mário Tanomaru Filho,Paulo Sérgio Cerri
RSBO , 2011,
Abstract: Introduction: Both Mineral Trioxide Aggregate (MTA) and Portland cement (PC) have been highlighted because of their favorable biological properties, with extensive applications in Endodontics, including the possibility of using into root canal filling. Objective: This article reviews literature related to MTA and PC comparing their physical, chemical and biological properties, as well as their indications. Literature review: Literature reports studies revealing the similarities between these materials’ properties, including both biocompatibility and bone repair induction. Moreover, there is the need for the development of a root canal sealer based on these materials (MTA and PC). Conclusion: MTA and CP show promissory perspective both in Dentistry and Endodontics.
Arsenic content in Portland cement: A literature review
Tenorio de Franca Talita,da Silva Raphaela,Sedycias de Queiroz Michellini,Aguiar Carlos
Indian Journal of Dental Research , 2010,
Abstract: Portland cement (PC) is a hydraulic binding material widely used in the building industry. The main interest in its use in dentistry is focused on a possible alternative to mineral trioxide aggregate (MTA) because PC is less expensive and is widely available. In dentistry, PC has been used in dental procedures such as pulpotomy, pulp capping, repair of root perforation and root-end filling. The purpose of this article is review the dental literature about the PC, its composition with special attention to arsenic content, properties, and application in dentistry. A bibliographic research was performed in Bireme, PubMed, LILACS and Scopus data bases looking for national and international studies about the PC composition, properties and clinical use. It was observed that PC has favorable biological properties very similar to those of MTA. The PC has shown good cell proliferation induction with formation of a monolayer cell, satisfactory inflammatory response, inhibitory effect of prostaglandin and antimicrobial effect. Studies have shown that PC is not cytotoxic, stimulates the apposition of reparative dentin and permits cellular attachment and growth. Regarding arsenic presence, its levels and release are low. PC has physical, chemical and biological properties similar to MTA. Arsenic levels and release are low, therefore, unable to cause toxic effects.
Influence of substitution of ordinary Portland cement by silica fume in the durability of slag Portland cement pastes in sea water
A. M. Radwan,E. A. El-Alfi,R. M. Othman
Journal of Engineering and Applied Sciences , 2012,
Abstract: Effect of gradually substitution of ordinary Portland cement by a few percent of silica fume (0.0, 2.5, 5.0 and 7.5 wt. %) on the durability of slag-Portland cement pastes up to 12 months immersed in sea water was investigated. The results show that the substitution of Portland cement by silica fume in the granulated slag-Portland cement pastes improves the physico-mechanical properties of the hardened cement pastes especially at early ages as well as gives a better resistance of cement stone to sea water attack at all immersing time. Also, the composite cement pastes containing 7.5% silica fume showed a maximum durability than other samples.
Characteristics of Portland cement pastes with high replacement of slag
A. M. Radwan,E. A. El-Alfi,R. M. Osman
Journal of Engineering and Applied Sciences , 2012,
Abstract: The influence of substitution of Ordinary Portland cement by ground granulated blast-furnace slag up to 70 % on the properties of silica fume-Portland cement composite pastes up to 12 months was studied. After one year, the composite cements pastes containing 50-70 % slag exhibit suitable strength values compared to without slag sample. Also, The XRD results show that the C-S-H are intensified with available increase indicating more dense structures and large amount of additional C-S-H in the presence slag content.
INFLUENCE OF SUBSTITUTION OF ORDINARY PORTLAND CEMENT BY SILICA FUME ON THE HYDRATION OF SLAG-PORTLAND CEMENT PASTES  [PDF]
E.A. El-Alfi,A.M. Rad wan,H. Abu -EL-Naga
Ceramics-Silikáty , 2011,
Abstract: Effect of gradual substitution of ordinary Portland cement by a few percent of silica fume (0.0, 2.5, 5.0 and 7.5 wt.%) on the hydration properties of slag-Portland cement pastes up to 12 months was investigated. The results show that the composite cement pastes containing silica fume give the higher physico-mechanical properties than that of the slag-Portland cement. Also, the XRD results reveal that the peak of Ca(OH)2 shows higher intensity in the sample without silica fume and completely disappears in the sample containing 7.5 wt.% silica fume content. Also, the intensity peaks of C4AH13 sharply increase with silica fume content.
The use of Portland cement in the repair of mandibular fractures in rats
Campello, Reginaldo Inojosa Carneiro;Vasconcelos, Belmiro Cavalcanti do Egito;Sampaio, Gerhilde Callou;Rolim, Antonio;Porto, Gabriela Granja;
Acta Cirurgica Brasileira , 2011, DOI: 10.1590/S0102-86502011000600004
Abstract: purpose: to evaluate the bone healing of mandibular fractures following the use of portland cement. methods: thirty-two male wistar rats were divided into control and experimental groups. in the control group the rats were submitted to a mandibular fracture, which was reduced, and the soft tissues were sutured. in the experimental group the rats had the mandibular fracture reduced and maintained with the portland cement. the animals were euthanized 7 and 21 days after surgery by injecting a lethal dose of anesthetic. the following variables were studied: weight of the animals, radiographic images, histopathological features and time of surgery. results: a weight loss was observed in the specimens of both groups at the different times of evaluation, a greater difference in weight before and after surgery being found in the experimental group, which was statistically significant (p <0.05, p = 0.041). from the histological point of view, with a margin of error (5.0%) the only two significant differences (p <0.05) recorded in the variables were "material deployed" and "bone resorption" during the evaluations at 7 and 21 days, respectively. conclusion: the portland cement served to promote bone healing.
Hydration of Portland Cement in the Presence of Highly Reactive Metakaolin  [PDF]
Alexey Brykov, Svetlana Krasnobaeva, Maxim Mokeev
Materials Sciences and Applications (MSA) , 2015, DOI: 10.4236/msa.2015.65044
Abstract: The degree of conversion of highly reactive metakaolin in Portland cement metakaolin paste at different ages as well as the influence of metakaolin on the degree of hydration of Portland cement and composition of C-S-H is investigated by?27Al- and 29Si-MAS NMR spectroscopy. At the age of 7 days, in the paste with 10% of metakaolin, the additive is completely consumed. In the 30% substituted cement paste, the content of metakaolin remains quite high (about 40% of the initial amount) even after 3 months of hydration. At the age of 1 - 3 months, the degree of Portland cement hydration in the presence of metakaolin is of 15% - 20% less than without it, probably, due to deficit of water or spatial restrictions. After 7 days of hydration, about half of C-S-H consists of material derived from metakaolin. Metakaolin mainly contributes to Q2 and Q2 (1Al) species, whereas PC does to Q1. After 1 day of hydration, an amount of ettringite in cement paste with high dosage of metakaolin is higher than in pure PC paste.
Portland cement hydration in the presence of admixtures: black gram pulse and superplasticizer
Dwivedi, Viveka Nand;Das, Shiva Saran;Singh, Nakshatra Bahadur;Rai, Sarita;Gajbhiye, Namdev Shriram;
Materials Research , 2008, DOI: 10.1590/S1516-14392008000400008
Abstract: effect of admixtures such as black gram pulse (bgp) and sulfonated naphthalene based superplasticizer (sp) on the hydration of portland cement has been studied. the hydration characteristics of opc in the presence of bgp and sp were studied with the help of non evaporable water content determinations, calorimetric method, m?ssbauer spectroscopic and atomic force microscopic techniques. results have shown that both bgp and sp get adsorbed at the surface of cement and its hydration products. the hydration of portland cement is retarded in the presence of both the admixtures and nanosize hydration products are formed.
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