International Concrete Abstracts Portal

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.

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

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

The corrosion of reinforcing steel embedded in concrete causes cracks and delamination in the concrete. The application of impressed current cathodic protection utilizing electrically conductive polymer concrete to distribute the current across concrete bridge deck surfaces is gradually becoming a standard practice in the highway industry. To protect the bridge substructures, a sprayable electrically conductive polymer concrete coating is being developed. This thin coating has a very low resistivity and can distribute the cathodic protection current across the concrete surfaces that are to be protected.

Lightweight polymer concrete composites have been developed with excellent insulating properties. The composites consist of lightweight aggregates such as expanded perlites, multicellular glass nodules, or hollow alumina silicate microspheres bound together with unsaturated polyester or epoxy resins. These composites, known as insulating polymer concrete (IPC), have thermal conductivities from 0.09 to 0.19 Btu/hr-ft-F. Compressive strengths, depending on the aggregates used, range from 1000 to 6000 psi. These materials can be precast or cast-in-place on concrete substrates. Recently, it has been demonstrated that these materials can also by sprayed onto concrete and other substrates. An overlay application of IPC is currently underway as dike insulation at an LNG storage tank facility. The composites have numerous potentials in the construction industry, such as insulating building blocks or prefabricated insulating wall panels.