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[Retention of fiber posts dependent on different resin cements]

Karl-Thomas Wrbas1, Martin T Kampe, Jörg F Schirrmeister

  • 1Klinikum der Albert-Ludwigs-Universität, Universitätsklinik für Zahn-, Mund- und Kieferheilkunde, Abteilung für Zahnerhaltungskunde und Parodontologie. thomas.wrbas@uniklinik-freiburg.de

Schweizer Monatsschrift Fur Zahnmedizin = Revue Mensuelle Suisse D'Odonto-Stomatologie = Rivista Mensile Svizzera Di Odontologia E Stomatologia
|February 14, 2006
PubMed

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Fiber-reinforced concrete significantly enhances the structural and nonstructural properties of traditional concrete by incorporating fibers like steel, glass, and polymers. These fibers, varying from natural ones such as sisal and cellulose to manufactured ones like polypropylene and Kevlar, are mixed into hydraulic cement with aggregates. Steel fibers, often preferred for their robustness, contribute to improved ductility, toughness, and post-cracking performance. The concrete is classified...
Retarders01:19

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Retarders are chemical admixtures designed to extend the setting time, which is especially useful when there is a delay in sequential concrete pours to prevent cold joints and to achieve a cohesive structure. Retarders, when used in appropriate amounts, can also enhance the architectural appearance of exposed aggregate finishes.
The function of retarders is to delay the setting of concrete, and this effect can be measured using a penetration test. The retardation process involves adding...
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Post-tensioned masonry walls use high-strength steel rods or flexible tendons to enhance the strength and efficiency of masonry structures. These elements are securely anchored to the foundation and extend vertically either within the cores of the masonry units or between the masonry wythes. The construction process involves building the wall with these tensioning elements in place and allowing the mortar to fully cure.
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The porosity of concrete is a measure of the void spaces within its structure. These spaces impact its strength and durability significantly. When water and cement interact, a chemical reaction called hydration creates a semi-solid paste. This paste includes combined water, making up approximately 23% of the cement's dry mass, and gel water, which fills minuscule voids known as gel pores, accounting for about 28% of the cement gel volume.
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Portland cement comes in several types, each with distinct properties and applications based on their chemical composition and hydration characteristics:
Type I (Ordinary Portland Cement) is widely used for general construction where special properties are not required. It has moderate sulfate resistance and heat of hydration.
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