Cement Reinforcement

The main characteristic properties of asbestos fibers that can be exploited in industrial appHcations (8) are their thermal, electrical, and sound insulation nonflammabiUty matrix reinforcement (cement, plastic, and resins) adsorption capacity (filtration, Hquid sterilization) wear and friction properties (friction materials) and chemical inertia (except in acids). These properties have led to several main classes of industrial products or appHcations... 

Reinforced cements contain other fillings that may be reactive. 

Table 14 Influence of Humidity on Flexural Strength and Fracture Toughness of Cellulose Fiber Reinforced Cements [78]...

Water-reducing plasticizers, fiber-reinforced cements.24... 

Bartos, P. (1981). Review paper Bond in fiber reinforced cements and concrete. Intern. J. Cement Composites 3, 159-177. 

An unusual application involves the use of carbon fiber to reinforce cement. This results in improved tensile and flexural strength, high impact strength, improved dimensional stability, etc. 

Fligh Performance Fiber Reinforced Cement Composites... 

Considerable effort has been devoted to finding alternative fibers or minerals to replace asbestos fibers in their applications. Such efforts have been motivated by various reasons, typically, availability and cost, and more recently, health concerns. During World War I, some countries lost access to asbestos fiber supplies and had to develop substitute materials. Also, in the production of fiber reinforced cement products, many developing countries focused on alternatives to asbestos fibers, in particular on cellulose fibers readily available locally at minimal cost. Since the 1980s however, systematic research has been pursued in several industrialized countries to replace asbestos fibers in all of their current applications because of perceived health risks. 

Fire tests in a 25-foot tunnel furnace were carried out according to standard ASTM E84 by the Underwriters Laboratory and the Hardwood Plywood and Veneer Association. Results are given for the flame spread index (FSI) and smoke developed index (SDI). The values obtained from burning the test materials represent a comparison with that of Va inch inorganic reinforced cement board expressed as zero and red oak flooring expressed as 100. 

The flame spread distance was observed and recorded every 15 seconds or every 2 feet of progression. The peak distance was noted at the time of occurrence. The flame spread distance was plotted over time. The total area under the flame spread distance-time curve was determined. The flame spread was then calculated as a function of the area under the curve relative to the standard red oak curve area. The value for flame spread classification was compared with that of inorganic reinforced cement board and select-grade red oak flooring. 

Flammability of materials is characterized by many different ways, one of them is the flame spread index (FSI). As reference values, FSI for inorganic reinforced cement board surface is arbitrarily set as 0, and for select grade oak surface as 100 under the specified conditions. FSI for ordinary wood species is typically between 100 and 200, and for some special cases it is as low as 60-70. An average FSI for about 30 different wood species is 125 45. 

Two separate (and not necessarily related) readouts of the test are (a) flame spread along the surface of the specimen as a distance traveled by the boundary of a zone of flame over time and (b) smoke developed as a change in optical density (as a progress curve of light absorption percent) between the light source and the photoelectric cell mounted in the vent pipe. These data are used to calculate the respective FSI and SDI as described in the ASTM test procedure. The indexes are calculated as relative values to those of select grade oak (FSI arbitrarily set as 100) and inorganic reinforced cement board (FSI set as 0) surfaces under the specified conditions. 

Fibers of refractory compositions can be drawn directly from solution (18). These fibers can be compacted for use in corrosive environments such as reinforced cement. 

SFRPCM, Steel fiber reinforced SBR-modified mortar CFRC, Carbon fiber reinforced cement... 

On account of their favorable properties and comparatively low price, bitumen paints have been used to protect concrete structures (foundations, bridge abutments), felt roofs, sheet-metal roofs, drinking water reservoirs, silos, pipes made from fiber-reinforced cement, concrete, steel and cast iron, and in vehicle construction (wagon underframes, car underfloor protection). 

Ahmed, S.F.U., Maalej, M. and Paramasivam, P. (2006). Flexural responses of hybrid steel-polyethylene fibre reinforced cement composites containing high volume fly ash. Journal of Construction and Building Materials, 21 1088-1097. 

Kobayashi, K., Lizuka, T., Kurachi, H. and Rokugo, K. (2010). Corrosion protection performance of high performance fiber reinforced cement composites as a repair material. Cement and Concrete Composites, 32 411 20. 

Miyazato, S. and Hiraishi, Y. (2005). Transport properties and steel corrosion in ductile fibre reinforced cement composites. Proceedings of ICE, Torino, Italy. 

J. Hegger, H. N. Schneider, A. Sherif, M. Molter, S. Voss, in Thin Reinforced Cement Based Products and Construction Systems, ACI-Special Publication SP-224 (2004), pp. 55-70. 

Q. Z. Yu Influence offabric geometrical structure on bonding of the fabric reinforced cement composites. Journal of Dong Hua University 24 (2007), No. 6, p. 765-770... 

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