Polyester Concretes

Keywords Polymer concrete, polyester, polyethylene, recycled materials... 

Epoxies are preferable to other resin systems in that they can be formulated to bond to moist hardened concrete and yet be able to cure within the wet environment of the fresh concrete. Polyesters do not generally bond reliably under wet conditions. The system must also be selected with due regard to the temperature of application. Resins claimed to have good bonding performance at 20 C may give rather poor bond strengths at the lower cure temperatures prevalent on UK construction sites during much of the year. 

I Adhesion to concrete primers generally are used under polyesters and urethanes to improve adhesion. 

Membranes are applied directly to the metal or concrete surface to protect from corrosion by any liquor that penetrates the brick lining through pores and cracks. Membranes consist of sheet material bonded to the metal or concrete, e.g., flexible PVC sheet, or it may be formed in situ (e.g., polyester resin reinforced with glass fiber, or synthetic rubber sheet, lead, polyisobutylene, polyethylene and asphalt). 

Polyester resin floor toppings, similar in performance to the epoxy toppings, have been used but, as indicated earlier, polyester systems tend to shrink and, without careful formulation and laying, shrinkage stresses with polyester resin systems can develop at the interface between the topping and the concrete substrate. Coupled with the additional stresses due to the differences in their coefficients to thermal expansion, this can cause failure at the surface of the concrete substrate." ... 

McCurrich, L. H. and Kay, W. M., Polyester and epoxy resin concrete, paper presented at the Symposium on Resins and Concrete, University of Newcastle-upon-Tyne, 17-18 April (1973). 

Polymers for Advanced Technologies 6, No. 11, Nov. 1995, p.688-92 MAKING POLYMER CONCRETE AND POLYMER MORTAR USING SYNTHESISED UNSATURATED POLYESTER RESINS FROM POLY(ETHYLENE TEREPHTHALATE) WASTE Abdel-Azim A AA Attia IA Egyptian Petroleum Research Institute Carro,Ain Shams University... 

High-temperature cement formulations are basically polymer concrete. Mainly unsaturated polyesters or vinyl ester resins with allylphthalate as vinyl monomer are in use [927]. Cming is achieved with peroxides, which decompose sufficiently fast at temperamres between 120° and 200° C. Polymer concrete requires additional materials, which compensate shrinkage. 

There are perhaps hundreds of miscellaneous unsaturated polyester resin construction applications. These would include window frames, doors, cabinet enclosures, electrical boxes, etc. In addition, recent developments bode well for unsaturated polyesters in construction markets. Concrete rebar, bridge construction and general infrastructure repair are examples of growing construction applications. 

The structural chemistry of alkyds has already been covered in Chapter 15, Section 7. Although there are over 400-500 varieties of such resins, they are all polyesters with carbon-carbon double bonds that can be cross-linked. They are very versatile in coatings, and their diverse properties can be matched for particular uses. They are the most widely used resins for protective coatings. Their best points can be summarized as follows (1) easy to apply (2) can have flat, semigloss, or high-gloss finish (3) useful for most surfaces except concrete or plaster (alkaline) (4) good color retention and (5) odorless (some of them). 

This happened on a unit I was supervising. A score of operators were lying on the concrete with their polyester shirts burning. This incident happened 20 years ago, before the need to wear fire-retardant Nomex coveralls was recognized. 

Impregnated wood, glass-reinforced polyester or precast concrete are acceptable materials for water basin. 

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