Polymer concrete precast

The method of producing precast polymer concrete is similar to that of precast Portland cement concrete. The extremely short hardening period of polymer concrete is an obvious advantage over Portland cement concrete. Form removal may be as short as 40 seconds, depending on the type of monomer used [11]. The formwork, vibrators and mixers used in producing polymer concrete precast elements are no different to those used for Portland cement concrete precast elements. Flowever, it should be noted that the formwork should be durable, smooth surfaced and must be able to withstand the heat developed during the exothermic polymerisation process. 

In the last decade and a half, various manufacturers have started to market precast and preformed gutters or trench sections of various plastics and polymer concretes, unfortunately in very limited dimensions, from which the user may assemble a trench or gutter to handle chemical wastes. The stated advantage of the use of such materials is quick and easy assembly, but the user should note that joints between these components are not always liquid-tight, and unless the... 

As the reader will realize, this procedure will not be very satisfactory for a cover for a steel tank. If it is a fixed dome or conical cover, it may be lined with brick, but if the cover is to be removable, the cover may be steel, employing a high temperature membrane, or a precast polymer concrete or prefabricated FRP construction. 

Silicate polymer concrete (SPC) is used in the repair of foundations, for the manufacture of storage tanks for hot and cold acids, equipment lining, reservoirs, and building structures, and as the structural material in vessel heads, vaults, and diaphragms. SPC is of particular interest in precast structures in production of pickling baths for metallurgical plants. 

Adhesion Strength of Joints of Precast Silicate Polymer Concrete Structural Members [5]... 

Source Reprinted from O. Figovsky and D. Beilin, Adhesion Strength of Precast Silicate Polymer Concrete Structure Member, Journal Scientific Israel Technology Advanced 13, no. 4 (2011) 96-102. With permission. 

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. 

Development of precast polymer concrete products and manufacturing processes (including mass production systems and continuous mixers) for them [46]... 

Other tertiary recycling processes that have been developed include a Freeman Chemical Corp. process to convert PET bottles and film to aromatic polyols used for manufacture of urethane and isocyanurates. Glycolized PET, preferably from film, since it is often lower in cost than bottles, can be reacted with unsaturated dibasic acids or anhydrides to form unsaturated polyesters. These can then be used in applications such as glass-fiber-reinforced bath tubs, shower stalls, and boat huUs. United States companies that have been involved include Ashland Chemical, Alpha Corp., Ruco Polymer Corp., and Plexmar. Unsaturated polyesters have also been used in polymer concrete, where the very fast cure times facilitate repair of concrete structures. Basing polymer concrete materials, for repair or precast applications, on recycled PET reportedly leads to 5 to 10 percent cost savings and comparable properties to polymer concrete based on virgin materials. However, they are still approximately 10 times the cost of portland cement concrete. There appears to be little commercial application of these processes at present. 

Applications of polymer mortars and polymer concretes include patching of Portland cement concrete, floor and pavement overlays, anti-corrosive linings, precast products, vaults, panels [8,11]. These indicate that there is no single polymer concrete that performs all of these tasks. Application and performance of polymer concrete depend on the binder used and the aggregate. Copolymerisation techniques allow the production of a wide range of binders with varying properties [11]. 

Precast Elements There are numerous applications of precast polymer concrete such as panels, pipes, drainage channels, tiles, bricks, linings, manhole structures, stair treads, electric insulators, etc. [11, 15]. 

Polymer concrete is a chemically resistant synthetic concrete consisting of low-viscosity binders and inert aggregates, which when combined and thoroughly mixed produces a synthetic material that can be precast or poured in place. They may also be used as a concrete surfacing. When applied in thicknesses greater than 1/2 in. (13 mm) it is considered a polymer concrete. When applied in lesser thickness the material is referred to as a surfacing or coating. 

Research on the process technology for precast products using polymer-impregnated mortar and concrete and for field polymer impregnation systems [12, 50, 51]... 

Development of the practical manufacturing processes for the precast products of polymer-impregnated mortar and concrete [56]... 

As mentioned in Introduction, recently polymer-impregnated mortar and concrete have hardly been used as construction materials except for a few applications. At present, their precast products such as permanent forms are manufactured to order at Materras Oume Co., Ltd. in Japan, which is their only manufacturer in the world. However, a recent great interest has been oriented toward the durability improvement of reinforced concrete structures by the concrete surface impregnation techniques using alkyl alkoxy silane-based barrier (or surface) penetrants, similar to the field polymer impregnation techniques [85]... 

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