Scientific Research Publishing

Read  full  paper  at: http://www.scirp.org/journal/PaperInformation.aspx?PaperID=53454#.VMWzFCzQrzE Author(s)    Oladipupo S. Olafusi , Adekunle P. Adewuyi , Abiodun I. Otunla , Adewale O. Babalola Affiliation(s) Department of Civil Engineering, College of Engineering, Federal University of Agriculture, Abeokuta, Nigeria . ABSTRACT This paper compared the rheological properties and compressive strengths of self-compacting concrete (SCC) and conventional cement concrete. The flowability and segregation resistance of freshly mixed concrete specimens were examined by the V-funnel apparatus, while the characteristics of passing ability were investigated with the L-box apparatus. Cylindrical concrete specimens of 100 mm diameter × 200 mm length were investigated for compressive strength. The rheological properties of SCC are incomparable with those of the conventional concrete due to their diverse testing methods and characteristics of ...

Read  full  paper  at: http://www.scirp.org/journal/PaperInformation.aspx?PaperID=53125#.VLXQ2cnQrzE Author(s)    Mark Bediako 1 , J. T. Kevern 2 , Eric Opoku Amankwah 3   Affiliation(s) 1 Council for Scientific and Industrial Research, Building and Road Research Institute, Materials Engineering Development Division, Kumasi, Ghana . 2 Department of Civil and Mechanical Engineering, University of Missouri, Kansas City, Missouri, USA . 3 Development Office, University of Education-Winneba, Kumasi Campus, Kumasi, Ghana . ABSTRACT Curing of cement based products such as concrete and mortar, is very important to achieve good strength and durable products. However the curing environment plays a pivotal role in the overall quality of cement based products in terms of strength development. ASTM C192 allows moist curing either in a fog room or under water. However, these must meet ASTM C511 which controls temperature, and specifically fo...

Read  full  paper  at: http://www.scirp.org/journal/PaperInformation.aspx?PaperID=53033#.VLSC18nQrzE Author(s)     Kenichi Tamura Affiliation(s) College of Engineering, Nihon University, Koriyama, Japan . ABSTRACT Regenerative artificial bone material and bone parts were fabricated using vacuum-sintered bodies of a “titanium medical apatite (TMA®)” that is formed by chemically connecting Ti oxide molecules to the reactive [Ca 10 (PO 4 ) 6 ] group of hydroxyapatite (HAp). Sintering at temperatures of 1273 - 1773 K caused this TMA sintered bodies to recrystallize and form a varying mix of α-TCP (tricalcium phosphate), β-TCP and Perovskite-CaTiO 3 phases. The Perovskite crystals proved to be quite stable and hard, forming a uniform distribution of similarly sized fibers in all directions under vacuum sintering, but an irregular distribution and size when sintered in the presence of oxygen. Complete recrystallization was achi...