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.

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.

A methodology has been developed for designing precast, fiber reinforced polymer concrete (FPC) vaults to be used in underground applications. The approach used in the design was to consider the vault as a series of plates: cover, walls, and foundation slab. Each plate was subjected to loads resulting from soil pressure, live loading, and dead weight and was analyzed using classical plate theory. This approach was verified by testing two quarter-scale models of a typical vault. Upon completion of the laboratory evaluation, two vaults were designed for use as underground, natural gas regulator stations. The vaults were manufactured and subsequently placed into service by Brooklyn Union Gas Company, and the Consolidated Edison Company of New York.

Industrial floors of asphalt concrete or other bituminous products are deformed under sustained concentrated loads. They are also dark in color and difficult to clean. Consequently, they need to be renovated. The use of polymer-modified concrete (PMC) overlays is an interesting alternative. Reinforced and unreinforced overlays were subjected to static and rolling wheel loads. Reinforced PMC overlays on asphalt showed a high load-carrying capacity. Shrinkage tests were carried out on PMC prisms and on concrete and bituminous overlaid with PMC. A two-layer overlay with wear and leveling layers was less prone to shrinkage than an overlay solely consisting of awear layer.