Rubberized Mortar from Rubber Tire Waste with Controlled Particle Size

Abstract Thermoplastic composites containing different Ground Rubber Tire (GRT) materials, Linear Low Density Polyethylene (LLDPE) and, in some case, a coupling agent (IB‘E’, an ethylene glycidyl methacrylate copolymer) were prepared by melt blending. The impact energies of all the thermoplastic composites (normally containing 40 wt % GRT) were evaluated using an instrumented impact tester. The effects of the GRT particle-size, particle size distribution and shape, the mode of grinding, and the oxygen surface concentration were analyzed. The wet-ambient-ground GRT based composites show higher surface oxidation and give better impact energy than cryo-ground and normal air-ground GRT based composites. Smaller GRT particle size results in a small increase in the impact property of the composite and a greater influence on the melt processability of the composites. Of the different GRT surface modification techniques studied for improved composite interfacial adhesion and impact properties the composites from electron beam radiation treated GRT yield higher increases in impact energy in comparison to corona and plasma treated GRT based composites.

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Effects of Rubber Size on the Cracking Resistance of Rubberized Mortars

Materials ◽

10.3390/ma12193132 ◽

2019 ◽

Vol 12 (19) ◽

pp. 3132 ◽

Cited By ~ 2

Author(s):

Yong Yu ◽

Han Zhu

Keyword(s):

Particle Size ◽

Mechanical Test ◽

Rubber Particle ◽

Inhibitory Effect ◽

Interfacial Transition Zone ◽

Particle Sizes ◽

Cracking Resistance ◽

Eccentric Ring ◽

Rubberized Mortar ◽

Restrained Ring

This study investigated the cracking resistance of rubberized cement-based mortars. Three rubber particle sizes were used: Rubber A (major particle size 2–4 mm), Rubber B (major particle size 1–3 mm), and Rubber C (major particle size 0–2 mm). Traditional restrained ring shrinkage test (RRST), new restrained squared eccentric ring shrinkage test (RSERST), mechanical test, and scanning electron microscopy test were conducted. Results showed that the cracking inhibitory effect of Rubber B was the highest among the three rubber particle sizes. SEM results revealed that the particle size of the rubber does not have much effect on the ITZ (interfacial transition zone) position of rubber and cement paste. For the strength differences of the three types of rubberized mortar, it is mainly because the specific surface area increased as the rubber size decreased, which lead to more ITZ positions and pore structures. Our study verified that RSERST can predict the cracking position and shorten the test period. Compared with RRST, RSERST can also increase the restriction degree. K R is defined as the intensification factor of RSERST restriction degree. The average intensification factor is K R ¯ = 1.17 .

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Microstructural characterization of laser-melted/roller-quenched dicalcium silicate

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100104972 ◽

1988 ◽

Vol 46 ◽

pp. 582-583

Author(s):

C. J. Chan ◽

K. R. Venkatachari ◽

W. M. Kriven ◽

J. F. Young

Keyword(s):

Particle Size ◽

Raw Materials ◽

Shape Change ◽

Microstructural Characterization ◽

Particle Size Effect ◽

Dicalcium Silicate ◽

Laser Melting ◽

Uniform Size ◽

Cell Shape Change ◽

Wide Range

Dicalcium silicate (Ca2SiO4) is a major component of Portland cement. It has also been investigated as a potential transformation toughener alternative to zirconia. It has five polymorphs: α, α'H, α'L, β and γ. Of interest is the β-to-γ transformation on cooling at about 490°C. This transformation, accompanied by a 12% volume increase and a 4.6° unit cell shape change, is analogous to the tetragonal-to-monoclinic transformation in zirconia. Due to the processing methods used, previous studies into the particle size effect were limited by a wide range of particle size distribution. In an attempt to obtain a more uniform size, a fast quench rate involving a laser-melting/roller-quenching technique was investigated.The laser-melting/roller-quenching experiment used precompacted bars of stoichiometric γ-Ca2SiO4 powder, which were synthesized from AR grade CaCO3 and SiO2xH2O. The raw materials were mixed by conventional ceramic processing techniques, and sintered at 1450°C. The dusted γ-Ca2SiO4 powder was uniaxially pressed into 0.4 cm x 0.4 cm x 4 cm bars under 34 MPa and cold isostatically pressed under 172 MPa. The γ-Ca2SiO4 bars were melted by a 10 KW-CO2 laser.

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Analytical Electron Microscopy study of two vehicle-aged automotive exhaust catalysts having dissimilar activities

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100153336 ◽

1989 ◽

Vol 47 ◽

pp. 272-273

Author(s):

Sooho Kim ◽

M. J. D’Aniello

Keyword(s):

Electron Microscopy ◽

Particle Size ◽

Noble Metal ◽

Catalyst Deactivation ◽

Analytical Electron Microscopy ◽

Microscopy Study ◽

Metal Particles ◽

Automotive Exhaust ◽

Exhaust Catalysts ◽

Analytical Electron

Automotive catalysts generally lose-agtivity during vehicle operation due to several well-known deactivation mechanisms. To gain a more fundamental understanding of catalyst deactivation, the microscopic details of fresh and vehicle-aged commercial pelleted automotive exhaust catalysts containing Pt, Pd and Rh were studied by employing Analytical Electron Microscopy (AEM). Two different vehicle-aged samples containing similar poison levels but having different catalytic activities (denoted better and poorer) were selected for this study.The general microstructure of the supports and the noble metal particles of the two catalysts looks similar; the noble metal particles were generally found to be spherical and often faceted. However, the average noble metal particle size on the poorer catalyst (21 nm) was larger than that on the better catalyst (16 nm). These sizes represent a significant increase over that found on the fresh catalyst (8 nm). The activity of these catalysts decreases as the observed particle size increases.

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