Concrete chemical resistance

Included in this category are materials such as concrete, chemical-resistant grouts, ceramics, and glass. These materials are highly resistant to chemical attack from most media normally encountered in the chemical process and pharmaceutical industries. In general, their usage is restricted as they tend to be brittle, have poor mechanical properties in tension, and are sensitive to thermal shock. 

In the sheeting market, the low density polyethylenes are less important than the high density resins. The high density resins have excellent chemical resistance, stress-crack resistance, durabiUty, and low temperature properties which make them ideal for pond liners, waste treatment faciUties, and landfills. In thicker section, HMW-HDPE sheet makes good containers, trays, tmck-bed liners, disposable items, and concrete molds. The good durabiUty, abrasion resistance, and light weight are critical elements for its selection. 

Most metals, concrete, and other constmction materials are corroded by hydrobromic acid. Suitable materials of constmction include some fiber glass-reinforced plastics, some chemically resistant mbbers, PVC, Teflon, polypropylene, and ceramic-, mbber-, and glass-lined steel. Metals that are used include HasteUoy B, HasteUoy C, tantalum, and titanium. The HasteUoys can only be used at ambient temperatures. Liquid hydrogen bromide under pressure in glass at or above room temperature can attack the glass resulting in unexpected shattering. 

Concrete and fiberglass vaults are often used, although they can be subject to environmentally induced cracks. Soil and clay liners are not allowed. Flexible hner systems have been developed that may be a cost-effective and environmentally sound alternative. State-of-the-art liner technology has overcome many of the previous problems with seams, low mechanical strength, and chemical resistance. 

Two-component epoxy resin water thinned dispersions are now being used as floor sealers. They have good adhesion to concrete as well as good chemical resistance. However, the particle size of the dispersion is comparatively large (approximately 1-1.5 microns) and consequently penetration into good-quality concrete is minimal and an on-surface seal is obtained. However, with porous low-quality concrete substances, considerable binding/strengthening, etc. of the surface can be achieved with water-dispersible epoxy resin-based floor sealer. 

Chlorinated rubber floor paints are probably the most common of the lower-cost floor paints on the market. They produce tough and chemically resistant coatings, but their adhesion to concrete is not always good. They tend to wear off in patches and cannot be considered as a durable floor treatment except under light traffic conditions. However, re-coating is a simple job and floors can easily be repainted over weekend shutdowns, for example. Similar paints based on other resins such as acrylics, vinyls and styrene butadiene are also used. 

Solvent-free high-build floor paints are available which can be readily applied with brush, roller or spray to a prepared concrete substrate to give a thickness of 0.10-0.20 mm per coat. Normally, two coats are applied and the first is often lightly dressed with fine sand or carborundum dust to give a non-slip, chemically resistant and durable colored floor, ideal for light industrial traffic conditions (for example, rubber-shod wheels). ... 

The original perforated collector pipes in landfills were made of concrete like those used in highway underdrain systems. As landfills became higher, the strength of such pipes became inadequate. Today, perforated PVC pipes are commonly used, as are HDPE pipes. New regulations require that all materials be tested for chemical resistance as part of the permit-approval process. 

C 1181 Standard Test Method for Creep of Concrete in Compression C 531 Standard Test Method for Linear Shrinkage and Coefficient of Thermal Expansion of Chemical Resistant Mortars, Grouts, and Monolithic Surfaces... 

C 579 Standard Test Method for Compressive Strength of (Method B) Chemical Resistant Mortars and Monolithic Surfacings C 882-87 Standard Test for Bond Strength of Epoxy-Resin Systems Used with Concrete C 884-87 Standard Test Method for Thermal Compatibility between Concrete and an Epoxy-Resin Overlay... 

Although the mix design of latex-modified mortar and concrete is done in much the same way as that of ordinary mortar and concrete, properties such as workability, strength, extendibihty, adhesion, watertightness and chemical resistance are controlled by the polymer-cement ratio rather... 

The presence of the cement hydrate/polymer comatrix in LMM and LMC confers superior properties, such as high tensile and flexural strengths, excellent adhesion, high waterproofhess, high abrasion resistance and good chemical resistance, when compared to ordinary cement mortar and concrete. The degree of these improvements however depends on polymer type, polymer-cement ratio, water-cement ratio, air content and curing conditions. Some of the properties affected by these factors are discussed below [87, 88, 93-95]. 

Several possible applications of concrete-polymer material includes sewer and pressure pipe, building material for housing, underwater structures, railroad ties, and chemically resistant material of construction for large desalination plants. The incorporation of colored dyes with the monomer allows concrete-polymer material to be considered for various esthetic applications, such as in decorative wall and floor tile. 

Floors call for special consideration. They need to be protected against moisture and chemical action. The best material is concrete with a chemical-resistant coating. The next best is good-quality linoleum, which should be kept clean and well waxed to help prevent the penetration of spilled solutions.This can be underlain with bitumen paper as an extra precaution against liquids getting through and damaging the sub-floor. A drain is useful but not entirely necessary if the floor is dried after spills. 

A chemical-resistant anti-fatigue floor mat is another good idea. An anti-fatigue mat will help you work longer and more comfortably, especially if your darkroom is in a basement or garage with a concrete floor. The mat will also insulate you from the cold. 

Many of the attributes of solvent-borne epoxy coatings could be carried over to the waterborne epoxy coatings. These same attributes are useful in the application of waterborne epoxies as adhesive systems. They include good adhesion to a variety of substrates such as metals, wood, concrete, glass, ceramics, and many plastics chemical resistance low shrinkage toughness and flexibility and abrasion resistance. 

Test Method for Adhesion in Peel of Elastomeric Joint Sealants Recommended Practice for Surface Preparation of Concrete for Application of Chemical Resistance Resin Monolithic Surfaces Method of Testing Release Papers Used with Preformed Tape Sealants Test Method for T-Peel Strength of Hot Applied Sealants Test Method for Tensile Adhesive Strength of Preformed Tape Sealants by Disk Method... 

Water-based decorative wall paint Low-viscosity solvent-free epoxy sealer 42 100 38 15 min 2 h 16 h Flat, decorative finish on walls and ceilings, for interior and exterior use Excellent penetrating sealer and adhesion promoter for concrete and prior to application of coatings, excellent chemical resistance... 

Concrete masonry unit (CMU) construction is widely used (Figure 6). It can prevent buildup of contaminants when finished with an epoxy or other smooth, chemical-resistant coating. Where retrofit is not a regular practice, the strength of concrete block and its long life recommend it. 

One of the most conspicuous advantages of sulfur concrete compared with cement concrete, besides its chemical resistance, is its strength development (Figure 1). Even with very strong and thus early-setting cements, cement concrete requires about 28 days for hydration in order... 

Concrete Coatings. The durability, weatherability, and chemical resistance of composites match up well with the required properties of protective coatings for concrete and other rigid materials. A typical application is the protection of concrete structures from the acid solutions used in metal ore leaching plants (9). In one such application, sulfur composite was applied to two leaching vats of a new experimental copper ore leaching facility (Figure 8). 

Tile adhesives High bond strength Chemical resistance Bonding ceramic tiles to concrete or steel... 

Epoxy coatings are considered a versatile choice for the construction industry because of their excellent adhesion to concrete, steel and metal surfaces and their chemical resistance, toughness and corrosion resistance. A variety of brands are marketed by manufacturers for different end-uses. In general, the protective purpose of these coatings is resistance to corrosion and chemical attack. 

Methacrylate-based coating resistance to ultraviolet radiation chemical resistance permeability to water vapour carbon dioxide resistance colour retention anticarbonation coatings for concrete and masonry... 

C-579 Compressive strength of chemical-resistant mortars, grouts, monolithic surfacing and polymer concrete (based on resin, silicate, silica and sulphur binders). 

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