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

A furfuryl alcohol-based polymer concrete (FA-PC) has been developed for use as an all-weather repair material for concrete and asphalt surfaces. For this application, the following criteria were established: high-strength at an age of one hour, placement of the materials possible during heavy precipitation over temperatures ranging from -32 to 52 C, and the chemical constituents low in cost with long-term stability when contained in a maximum of three packages during storage. A formulation consisting of furfuryl alcohol monomer (FA), à,à,à-trichlorotulene, pyridine, silane, zinc chloride, silica filler, and coarse aggregate meets these requirements. Optimized formulations were established for use with premixed and percolation placement methods. The premixed formulation meets essentially all of the property and storage criteria and is compatible with moisture contents up to 4 percent by weight of the total mass, which stimulates placement in a 2.54 cm/hr rainfall. The working time for the FA-PC slurry can be controlled at ñ15 min over the operating temperature range -20 to 52 C by simply varying the à,à,à-trichlorotoluene catalyst concentration while holding all the other constituents constant. Below -20 C, slight increases in FA and ZnCl2 concentrations are needed to yield optimum properties. Prototype equipment for the mixing and placement of FA-PC was constructed and used in a series of tests up to a size of 6 x 6 x 0.15 m. The equipment consisted of a concrete transit mix supply of mixed aggregate, a hopper-fed volumetric feed screw that supplied aggregate at a known rate to a mixing screw, and a monomer pump and spray nozzle. The unit mixed and delivered FA-PC at ÷ 182 kg/min. The practicability of using equipment currently employed for the continuous placement of conventional portland cement concrete was proven. Field tests were performed under rainfall and dry conditions at temperatures ranging from -15 to 35 C. In all of these tests, the mixing and placement equipment performed well and the FA-PC slurries exhibited self-leveling characteristics. Test results from proxy samples prepared during the placement of the patches and cores taken after simulated aircraft trafficking indicated that the property requirements at an age of one hour were attained.

Polymer-modified concretes have been subjected to various climate conditions over seven years to find out differences in their hardening characteristics and in particular, the influence of temperature and moisture on the development of strength and elasticity. Generally, the resistance of concrete to long-time exposure conditions is clearly improved by the investigated dispersions, regardless of their generic types. This could be recognized more by the change in the dynamic modulus than by the compression test, which may pretend sound materials while the dynamic modulus points out structural defects. To compare dynamic moduli, the content of moisture has to be taken into account. A special correlation between moisture content, density, and the change of dynamic modulus of elasticity has been given.

One brand of polymer concrete beams reinforced with fiberglass rods were tested and evaluated in simple flexure. Testing was carried out by the applying of two equal loads symmetrically placed about the center line of the beam on simply supported spans of 51, 63, and 72 in. The distance of the load points from the center line of the beams was varied to change the available development length for the reinforcing rod. The primary experimental data consisted of strains measured by means of electrical resistance strain gages placed on the surface of the polymer concrete and along the reinforcing rod. These strains were used to establish cracking strains and bond strengths for the beams tested. The results indicate a range of values for cracking strains and bond strengths, the lowest cracking strain being 370 psi and the lowest bond strength, 434 psi.