Epoxies in the Construction Industry

In this book I have confined discussion to those polymeric materials which are cured by chemical reaction and which have found widespread application in the construction industry. As such, the book covers materials based on epoxies, polyurethanes, silicones, polysulphides, alkyds and polyesters. In addition, there is a chapter on hybrid polymer systems and one on acrylics. It is true that acrylic emulsions are not strictly thermosetting polymer systems, but their widespread use and importance made their exclusion difficult. These materials find use as coatings, sealants, adhesives, grouts, flooring compounds, repair compounds and waterproofing agents. 

The rate of curing depends primarily on the reactivity of the resin and curing agent. It is also dependent on the quantity of mix and on temperature. The materials used in the construction industry that can be bonded with epoxy resin adhesives are metals and metal alloys, concrete, natural stone, fibre cement and plaster, ceramic materials, glass, china and porcelain and wood. 

The principal characteristics of epoxy resins, as used with concrete, in the construction industry, include ... 

Pre-cast concrete has achieved a recognized position in the construction industry. Quite often, it is necessary to provide a decorative surface to these panels. Ti common method is to produce an exposed aggregate finish. Many architects now specify concrete panels having a veneer of marble, granite, limestone or other decorative natural stone. These veneers are applied in sections no thicker than 3/4 inch. Epoxy adhesives are used to bond the concrete to the veneer. 

It is sometimes recommended that persons subject to allergy should not be allowed to come in contact with epoxy resin systems. This would be an improbably measure to observe, it must be kept in mind that exposure to epoxy resin systems cannot cause anything but skin dermatitis. There has been absolutely no evidence of any carcinogenic effect from contact with these systems. Where slight irritations occur, desensitization should first be attempted. If eczema occurs, standard medical treatment should be provided. Antihistamine drugs may be used only to reduce itching. In severe cases, such as in the second stage of dermatosis, cortisone ointments have been used successfully to relieve the symptoms. It should be kept in mind that if protective measures are scrupulously observed, incidents of dermatoses from epoxy resin systems can be kept to a very low minimum. There is no reason for any concern in the use of these systems in the construction industry. 

Epoxy resin compounds are being recognized by architects and engineers for their varied chemical and physical properties. As technical people become more aware of the potential values of these systems, in use with concrete in the construction industries, greater uses will be made of a greater variety of formulations. However, caution should be exercised by all those who specify these compounds, that the epoxies are not a cure-all for all problems, that epoxies may be detrimental in some applications, and that proprieta.ry compounds should be thoroughly evaluated before they are used. 

Requirements of the adhesive. A full compliance spectrum for steel/concrete bonding has been published by the authors(18) and is reproduced as an Appendix at the end of the book. The purpose of the adhesive is to produce a continuous bond between steel and concrete to ensure that full composite action is developed by the transfer of shear stress across the thickness of the adhesive layer. Experience has shown that the best chance of success is likely to be achieved by using cold-cure epoxy based adhesives which have been specially developed for use in the construction industry. Provided that the surfaces have been prepared properly, these bond well to both steel and concrete and do not suffer shrinkage and cracking problems such as may occur with other systems like polyesters. For these purposes a cold-cure adhesive is defined as one which is capable of curing to the required strength between the... 

Fique Epoxy DGEBA Pultrusion Replacing wood and engineered wood products in the construction industry [10]... 

Synthetic thermosetting polymers used in the construction industry are polyester, vinylester and epoxies these materials are generally used to manufacture parts of the machines that produce sustainable energy generators. In addition, thermoplastic resins, such as polyetheretherketone (PEEK), polyethersulphone (PES) and various liquid crystal polymers (LCP) are also used. The latter high performance polymers also meet stringent out-gassing (relevant to space environments) and flammability requirements. 

Workers in the electronics, optical, paint and glue industries are most likely to acquire occupational allergy to epoxy resins (Richter 1974 Tosti et al. 1993). A Dutch survey among employees of several companies that specialise in epoxy resin-related work in the construction industry revealed hand eczema in 23 of 135 persons. Of these, 61% of the eczema population and 12% of the healthy skin group had positive patch-test reactions. Almost all positive patch-test reactions were due to epoxy resin This shows the tremendous relevance of epoxy resin as occupational allergen (van Putten et al. 1984). Epoxy resin coated fiberglass fibres have been reported as a cause of dermatitis in this particular field of industry (Holness and Nethercott 1989). 

When used for industrial adhesive purposes, epoxy resins occur mostly in the construction industry, the assembly of cars, ships, and aeroplanes, the manufacturing of sports equipment, as well as in the optical and electronic industries. Much is similar between the chemistry of epoxy resins and acrylates. Both are (often) two-component systems. They are not sensitising when fully cured but frequently contain an amount of remaining monomer, which is enough to... 

Fibre-reinforced polymer (FRP) composites are composed of fibres and matrices, which are bonded through the interface to ensure that the composite system as a whole gives satisfactory performance. Part 1 deals with FRP composite matrix materials which provide the foundation for composite materials. Chapter 2 reviews the chemistry of phenolic resins together with their mechanical and thermal properties. Chapter 3 discusses polyester thermoset resins as matrix materials. An overview of the chemistry of vinylester resins, together with their mechanical and chemical properties, as well as their use as a matrix material in the construction industry, is provided in Chapter 4. The final chapter in Part 1 begins with a review of the epoxy resins commonly available on the market, and then focuses on the principal characteristics of epoxy resin composite systems and their practical applications. 

The polyester resin may be modified with methyl methacrylate resins for better clarity and transparency. Recent developments involve the use of acrylates or polyvinyl flnoride as surface coatings bonded to the laminate for longer gloss retention. The prodnct is cnred at ambient temperatures, although heat will accelerate the cure and ensure a more satisfactory laminate. The same procedures are also followed in producing epoxy-resin laminates, although these are not as widely used in the construction industry. 

In the construction industry, epoxy resins find a variety of applications such as adhesive mortars, composite materials, and coatings. Epoxy polymers show excellent adhesion to the most common metals, glasses, ceramics, concretes, and other materials. 

Epoxy resin has superior properties such as high adhesion and anticorrosion, and has widely been used as adhesives and anticorrosives in the construction industry in the world. Provided the incorporation of the epoxy resin into cement mortar can give its superior properties to the mortar, it is possible to produce a highly polymer-modified cement mortar. The first patent of an epoxy-modified cement system was taken by Donnelly in 1965 [1]. Since the patent, 30 or more papers on the epoxy resin modification of the cement mortar and concrete have already been published [2]. Most epoxy resin-based cement modifiers dealt with in the papers are specially compounded by the manufacturers, and the procedures for mixing them to fresh mortar and... 

The two major uses of phenol in 1995 were the production of bisphenol-A (35%) and the production of phenolic resins (34%) (CMR 1996). The largest use for bisphenol-A is as an intermediate in the production of epoxy resins (Thurman 1982). Phenol-formaldehyde resins comprise over 95% of this market (Thurman 1982). The plywood adhesive industry required 26% of the total production of phenolic resins in 1977. These low-cost, versatile, thermoset resins have other major uses in the construction, automotive, and appliance industries (Thurman 1982). 

Thermosets A number of thermosets have been used as adhesives. Phenolic resins were used as adhesives by Leo Baekeland in the early 1900s. Phenolic resins are still used to bind together thin sheets of wood to make plywood. Urea resins have been used since 1930 as binders for wood chips in the manufacture of particle board. Unsaturated polyester resins are used for body repair and PUs are used to bond polyester cord to rubber in tires, and vinyl film to particle board, and to function as industrial sealants. Epoxy resins are used in the construction of automobiles and aircraft and as a component of plastic cement. 

Epoxy-nitrile Nitrile-epoxy adhesives are composed of solid epoxy resin modified with carboxyl-terminated butadiene nitrile (CTBN) copolymer. The CBTN is introduced into die epoxy resin at elevated temperatures. The modification provides toughness and high peel strength without sacrificing heat and chemical resistance. The film adhesives are widely used in the aerospace industry in the construction of jetliners. 

Epoxy-polysulfide systems are used in the construction, electrical, and transportation industries because of their unique combination of cured flexibility, adhesion to many substrates, and chemical resistance. They are typically used as adhesives for... 

Among the countless number of applications of polymers, the construction industry is one which utilises several polymeric materials. In this book I cover those polymeric materials which are single or bicomponent systems and are cured at ambient temperature either with the aid of curing agents or atmospheric moisture. The various polymers used in manufacturing such products include epoxies, polyurethanes, acrylics, silicones, polysulphides, alkyds and polyesters. As a result of innovation, new technologies exist which utilise more than one polymer in a single product. Such systems are discussed in Chapter 10, on hybrid polymers. 

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