Polymer concrete binder types

The polymer concretes are distinguished by the nature of the binder e.g., furan, polyester, epoxy, phenol formaldehyde, carbamide, and so on. The classification of the main types of polymer concrete according to the kind of synthetic resins involved is shown in Figure 1.2 [7],... 

The most effective scopes of polymer concrete application, depending on the type of polymeric binder, are shown in Table 1.6. 

PIC is a precast and cured portland cement concrete that has been impregnated with a monomer that is subsequently polymerized in situ. This type of cement composite is the most developed of polymer-concrete products. PCC, on the other hand, is a modified concrete in which a part (10%-15% by weight) of the cement binder is replaced by a synthetic organic polymer. It is produced by incorporating a monomer, prepolymer-monomer mixture, or a dispersed polymer (latex) into a cement-concrete mix. To effect the polymerization of the monomer or prepolymer-monomer, a catalyst (initiator) is added to the mixture. The process technology used is very similar to that of conventional concrete. So, unlike PIC which has to be used as a precast structure, PCC can be cast-in-place in field applications. PC can be described as a composite that contains polymer as a binder instead of the conventional portland cement. 

Organic coatings are used to block the penetration of carbon dioxide or chloride ions. They form a continuous polymeric film on the surface of the concrete, of a thickness ranging from 100 to 300 pm. The binder can already be present in the liquid paint as a polymer, or the polymer can be formed due to chemical reactions between monomeric components that are mixed just before application. Modem coating systems are usually built up of several layers applied consecutively. They are compatible with the alkalinity of the concrete and are based on various types of polymers (e. g. acrylate, polyurethane, epoxy), pigments and additives, and are made suitable for application by the addition of solvents or diluents. 

Regardless of polymer type, the compressive strength (ac) of latex-modified concrete can be predicted at polymer-cement ratios of 5, 10,15and 20% by using the binder-void ratio (a) as follows ... 

Latex-modified mortar and concrete are made by using a composite binder of inorganic cements and organic polymer latexes, and have a network structure which consists of cement gels and microfilms of polymers. Consequently, the properties of the latex-modified mortar and concrete are markedly improved over conventional cement mortar and concrete. The properties of the fresh and hardened mortar and concrete are affected by a multiplicity of factors such as polymer type, polymer-cement ratio, water-cement ratio, air content, and curing conditions. 

Concrete-polymer composites are the materials made by replacing a part or all of the cement hydrate binders of conventional cement mortar or concrete with polymers, and by strengthening the cement hydrate binders with the polymers. The concrete-polymer composites are generally classified into the following three types by the principles of process technology for them ... 

Density tests. Referring to Table 2 below, the densities of all the trial mixes ranged from just above 1000 kg/m to 1073 kg/m. The addition of polymers into the trial mixes had a negligible effect on the densities of the concrete. The control mix, CL had a density of 1034 kg/m which is very close to the densities of the other trial mixes thus the density of the concrete is affected more by the lightweight aggregate and cement binder content rather than by the quantity or type of polymer addition. 

In this research the polymer superplasticiser (PSP) was found to be more efficient than ordinary superplasticiser (SP) in increasing the flow of the mix, but appeared to have a negative effect on the compressive strength of the concrete (Figures 53 and 54). This might be due to the retarding effect of this type of superplasticiser on the blended binder. Moreover, it would impose an extra cost when using this type of concrete made with waste materials. 

In ordinary concretes, Portland cement combined with sand and water is used as the matrix or the binder. The inclusions are composed of coarse aggregate made of natural stones with specially selected grain fractions. Under the term concrete-like composites falls a large group of materials which, with respect to ordinary concretes, all constituents may be replaced by other materials. Not only are Portland cements used as binders but also for other types of hydraulic cements, bitumens, polymers and resins. The natural stone grains are replaced by various kinds of artificial lightweight... 

Effects of Control Factors for Mix Proportions. The binder of latex-modified mortar and concrete consists of polymer latex and inorganic cement, and their strength is developed as a result of an interaction between them. The polymer-cement ratio has a more pronounced effect on the strength properties than the water-cement ratio. However, this effect depends on polymer type, air content, curing conditions, etc. The relation between the strength properties and polymer-cement ratio has been discussed in a number of papers.A general trend which summarizes the results obtained in these papers is presented in Fig. 4.19. 

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