International Concrete Abstracts Portal

Recycled polyethylene terephthalate (PET) plastic wastes could be used in the production of unsaturated polyester resins. If specially formulated, these unsaturated polyester resins could, in turn, be mixed with inorganic aggregates to produce polymer concrete (PC). The results of an extensive research confirm that PC materials using resins based on recycled PET are comparable in strength to conventional PC materials. Resins based on recycled PET could also easily be altered to achieve a relatively wide range in the strength and flexibility properties of the PC, depending on the intended use of the material. PC using resins based on recycled PET may be utilized in the repair and overlay of portland cement concrete structures or in the production of various precast products, such as utility, transportation, and building components. The recycling of PET in PC would help decrease the cost of PC products, save energy, and alleviate an environmental problem posed by plastic wastes.

The use of porous materials as top layers of pavements is currently increasing in several European countries due to their noise absorption effect and an improvement in the drainage properties of the pavement. These effects are considered essential because of environmental and safety reasons. In this context, porous concrete is being studied as an alternative to porous asphalt. Since the porosity of this material significantly reduces its strength, some additions, in particular polymers, are required to obtain adequate mechanical properties and durability. These additions increase the cost of the pavement. To counteract this, the thickness of porous material is reduced to a thin layer; a bottom dense concrete, bonded to the porous top, must be laid. One such study was carried out by Dutch, German, and Spanish companies within the scope of a research project funded by the European Commission. This project included the analysis of noise production mechanism and noise measurement, the study of the behavior of porous concrete, the construction of test sections, the investigation of low noise by surface treatment, and the assessment and establishment of a practice code and guideline for the design and construction of porous concrete pavements. With respect to the laboratory research on porous concrete, the main objective was the definition of several mix compositions and a study of their characteristics of behavior. This paper presents the results obtained in the fatigue testing program carried out in this research project. It included compressive strength tests, the definition of the W÷hler curves (S-N diagrams) for several polymer contents and for different stress ratios, and the statistical analysis of experimental results.

SP-166 This volume contains 11 symposium papers that were presented at the 10th and 11th symposia that were held in Minneapolis, MN and Tarpon Springs, FL in 1993 and 1994 respectively. There were a total of four sessions, the first titled "Polymer Concrete Overlays," the second "Recent Innovations in Polymer Concrete Technology", the third and fourth "Structural Properties of Polymer Concrete, Part I and II."

There is an interest in developing better performing (high strength and ductility) composite structural elements for construction and repair of onshore and offshore structures. In this study, composite structural elements that consist of filled columns and sandwich columns (two concentric circular steel tubes with polymer concrete sandwiched in between) were investigated as potential compression members. High-strength (480 Mpa) and low-strength (200 MPa) steel tubes conforming to ASTM A513 Type 5 and ASTM A500 Grade B, respectively, were used. The polymer concrete was polyester based with a compressive strength of 60 Mpa. Short composite columns, made of steel tubes of diameter-to-thickness ratios ranging from 16 to 170, were tested under monotonically increasing axial compression. It was observed that the composite columns had compressive strengths of 10 to 30 percent higher than that of the summation of the individual components. The ductility was much higher than that of the corresponding steel tubes. Relationships for predicting the initial modulus and peak load and corresponding strain of the sandwich column have been developed. A simple model was used to predict the load-strain history up to the peak load of the composite elements. The predictions agreed well with the test results.

Very little research has been done on the structural behavior of steel-reinforced polymer concrete (PC). In all the previous studied, it was generally assumed that the structural behavior of reinforced PC is similar to the structural behavior of reinforced portland cement concrete because both are composite materials consisting of a binder and inorganic aggregates. However, the design equations developed for steel-reinforced portland cement concrete yield very conservative results when applied to reinforced PC. The objective of this paper is to report on the shear and flexure properties of steel-reinforced PC beams using unsaturated polyester resins based on recycled polyethylene terephthalate (PET) plastic waste. The effects of the shear span-to-depth ratio, reinforcement ratio, and compressive strength were investigated with the shear beams, while the effect of reinforcement ratio was investigated with the flexure beams. New design equations were also developed to predict the shear and flexural strength of steel-reinforced PC beams.