International Concrete Abstracts Portal

Polymer concrete is a composite material that is often a viable alternative to portland cement concrete. The mechanical and durability properties of three high-molecular weight methacrylate polymer concrete systems using different monomers are discussed. Properties discussed include compressive strength, flexural bond testing, modulus of elasticity, coefficient of thermal expansion, shrinkage, freeze thaw, freeze-thaw shear bond, water absorption, chemical resistance, and crack repair. The monomers themselves were shown to be very effective in sealing cracks with widths as narrow as 0.5 mm while restoring flexural strength.

Providing the latest advances in research, design and technology, this ACI symposium publication offers state-of-the-art information and greater insight into the latest use of polymer modified concrete and polymer concrete composites.A collection of 11 symposium papers, Polymer Modified Concrete deals exclusively with the various effects of polymers in concrete and provides an extensive source of reference. Bringing together expertise from around the world, case studies include: lightweight polymer concrete composites, polyester polymer concrete under flexural loading, flexure and bond in fiberglass-reinforced polymer concrete beams, and strength losses of polymer-modified concrete under wet conditions. Filled with illustrations, photos, and graphs, Polymer Modified Concrete provides in-depth answers to all of your questions. Note: The individual papers are also available as .pdf downloads.. Please click on the following link to view the papers available, or call 248.848.3800 to order. SP99

New Zealand has a predominantly agricultural-based economy and, thus a heavy investment in processing buildings such as export abattoirs and dairy factories. Component failures in these types of plants may have a serious effect on production and profitability. During the past 10 years, the Building Research Association of New Zealand has carried out an extensive research program investigating properties in the laboratory and in use on flooring materials for abattoirs. During the course of these investigations, it became clear that the formulation of widely used commercial polymer concrete toppings could be improved. In particular, these investigations sought a reduction of the resin content below the common figure of approximately 20 percent by weight and alternative aggregate sources to the limited supply of light-colored quartz and quartzite sands. However, it was important to preserve the application of new alternative mixes by trowelling, the traditional method. By starting from the aggregate grading curves of Weymouth and BS 882 and by using gap-grading, it was possible to lower the resin content to percent or less and still retain trowellability while using aggregates from traditional sources. Alternative sources of aggregates, such as sandstone (greywacke) and basalt, that could be used to produce the light-colored floors considered imperative for hygiene by the industry were found. The experimental polymer concrete floor toppings were tested for the necessary mechanical properties (compressive strength, abrasion, and impact resistance) for abattoir use.

The creep of unsaturated polyester/styrene polymer concrete (PC) under flexural loads was investigated using two PC systems with different resin contents, as well as the unfilled resin. Measurements were taken at temperatures, ranging from -5 to 60 C, time periods up to 160 hours, and stress levels from 4 to 12 MN/m², which represent stress-to-strength ratios of 0.3 to 0.7. The data obtained over these ranges of temperature, stress, and resin content were successfully superposed on a single master curve of creep compliance versus time. On the basis of these results, the authors propose a single expression that describes the creep compliance of the PC system as a product of separable functions of temperature, stress, resin content, and time

Conventional portland cement concrete and concretes with latex and epoxy additives were prepared and tested for their microstructure characteristics using the scanning electron microscope (SEM). The chloride-ion penetration profiles were also studied on 10-cm concrete cubes that were immersed in 15 percent NaCl solution for 21 days. Following the 21-day soaking period and a subsequent 21-day air-drying period, concrete powder samples were removed by drilling at depth intervals of 0 to 12, 12 to 25, 25 to 38, and 38 to 50 mm and tested for acid-soluble chloride-ion content using a potentiometric titration procedure. The results of these investigations and typical micrographs are presented.