Acrylic-polymer modified GRC

West, J. M.; Vekey, R. C. de; Majumdar, A.J.

doi:10.1016/0010-4361(85)90656-1

Cited by 10 publications

(2 citation statements)

References 2 publications

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“…Los primeros estudios fueron realizados en los primeros años de la década de los 70 del siglo pasado (de Vekey y Majumdar (1975))pero los resultados no se obtuvieron hasta finales de la década de los 80 (West et al (1985)), (Majumdar et al (1987)). En estos estudios se usaron cementos Pórtland ordinarios y cementos Pórtland con unas adiciones del 40 % de cenizas de alto horno y un 10 % de polimeros respecto del peso de cemento y también respecto del peso de la unión de cemento y cenizas.…”

Section: Envejecimientounclassified

Resistencia a impacto de morteros de cemento reforzados con fibra de vidrio (GRC)

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The origin and use of cementitious materials dates from the civilization's origin. Egyptians were the first people that used hydraulic materials as gypsium; Romans and Greeks used volcanic ashes mixed with lime that produced a much better material than gypsium. However, Romans were the first to use cementitious mixes in common buildings.As is well known cementitious mixes are brittle and have a high compressive strength.To get a material with better mechanical properties reinforced concrete was developed, it is a compound of steel bars inside a concrete bulk. However, corrosion in steel bars appear due the chemical attack from the environment, and to avoid this phenomenon steels bars should have a few centimeters of concrete covering them. By doing so, elements of great mechanical properties are obtained but these elements are also very heavy. To solve this problem glass fiber reinforced cement (GRC) was developed based in the previous works done with glass fibers and polymeric matrices. GRC has the great compressive strength of cement mortars and the tensile strength of the glass fibers. GRC's superior mechanical properties are reduced with time. GRC becomes brittle, losses all ductility and its behavior can be considered as lineal and elastic up to failure. Aged GRC has the same behavior as cement mortar without any reinforcement. In order to reduce or avoid this harmful process, some chemical products have been added to the cement paste during GRC's manufacturing.In this work, a wide experimental programme has been carried out to evaluate the influence of the 6 chemical products added in GRC's mechanical properties. Pure tensile tests and 4 point bending tests have been done both in young GRC and in aged GRC (aged artificially IX Abstract by immersion in hot water tanks). GRC samples were aged up to a natural ageing process of 30 years.A wide and thoroughly study has been done in GRC fracture surfaces of tensile tested samples using an Scanning Electronic Microscope (SEM) searching the causes of the fragilization of GRC with time.GRC dynamic behavior and properties have been widely studied by doing medium and high strain rate tests. Medium strain rate tests were carried out in a drop machine on GRC plates. GRC's ballistic behavior was studied shooting steel spheres into GRC samples.Numerical simulations of the different tests were performed to analyze which GRC's mechanical properties have influence in the behavior of the material during the tests. GRC ageing was simulated by changing the characteristics of the fiber-matrix interface.Dynamic simulations were carried out in Autodyn v6 in order to check which GRC's properties had influence in GRC's dynamic behavior. X Capítulo 1Estado del arte 1.1. Descripción y fabricación del GRC El GRC es un material compuesto que está formado por una matriz de mortero de cemento y fibras cortas de vidrio. Fue ideado alrededor de 1950 como consecuencia del éxito de los materiales compuestos de matriz polimérica reforzados con fibras de vidrio. Se intentaron sustituir las arma...

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Section: Envejecimientounclassified

Resistencia a impacto de morteros de cemento reforzados con fibra de vidrio (GRC)

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“…The addition of polymer latex has also contributed to improved paste-coarse aggregate bond strength (Kim et al 1999;Morin et al 2011) and lower drying shrinkage and creep (Al-Zahrani et al 2003;Ohama 1975) in latex-modified concrete. The inclusion of polymer latex in fiber reinforced mortar or concrete has been reported in few papers (Soroushian et al 1993;West et al 1985;Cao et al 2001). The addition of polymer latex may also influence the temperature sensitivity of cement-based material as shown in Mechtcherine et al (2012) that polymer fiber reinforced cement-based material shows strong temperature sensitivity.…”

Section: Introductionmentioning

confidence: 98%

Latex-modified Engineered Cementitious Composites (L-ECC)

Chen

Yang

Yao

et al. 2014

ACT

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This paper reports the influence of polymer latex on the fresh and the hardened properties of engineered cementitious composites (ECC), a unique strain-hardening cement-based material featuring extreme tensile strain capacity of 3-5%. Ethylene-vinyl acetate (EVA) dispersible polymer powder was employed in the synthesis of latex-modified ECC (L-ECC). The effects of EVA dosage on viscosity, air content, compressive strength, direct tensile stress-strain relation, four point bending behavior, and microstructure of L-ECC were reported. It was found that the addition of EVA increases the viscosity and the air content of fresh mixture. While the compressive and the tensile strength of L-ECC decrease with increasing EVA dosage, the tensile strain capacity and the toughness of the resulting material show significant enhancement. This is attributed to the change of microstructure as evidenced by the SEM images when EVA is used in the mixture.

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