Polymer concrete

Key takeaways

Polymer concrete belongs to chemistry; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Polymer concrete to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Polymer concrete from memory before moving on to harder problems.

Reference excerpt

Polymer concrete is a type of concrete that uses a polymer to replace lime-type cements as a binder. One specific type is epoxy granite, where the polymer used is exclusively epoxy. In some cases the polymer is used in addition to Portland cement to form Polymer Cement Concrete (PCC) or Polymer Modified Concrete (PMC). Polymers in concrete have been overseen by Committee 548 of the American Concrete Institute since 1971. The term "polymer-based concrete" (PBC) serves as an umbrella term for subtypes, which are distinguished by their binder, composition and performance.

Composition In polymer concrete, thermoplastic polymers are often used to form a film at the interface between the cement matrix and the aggregate, subsequently improving bonding and lowering permeability, however more typically thermosetting resins are used as the principal polymer component due to their high thermal stability and resistance to a wide variety of chemicals. Polymer concrete is also composed of aggregates that include silica, quartz, granite, limestone, or other material. The aggregate should be of good quality, free of dust and other debris, and dry. Failure to fulfill these criteria can reduce the bond strength between the polymer binder and the aggregate.

Uses Polymer concrete may be used for new construction or repairing of old concrete. The adhesive properties of polymer concrete allow repair of both polymer and conventional cement-based concretes. The corrosion resistance and low permeability of polymer concrete allows it to be used in swimming pools, sewer structure applications, drainage channels, electrolytic cells for base metal recovery, and other structures that contain liquids or corrosive chemicals. It is especially suited to the construction and rehabilitation of manholes due to their ability to withstand toxic and corrosive sewer gases and bacteria commonly found in sewer systems. Unlike traditional concrete structures, polymer concrete requires no coating or welding of PVC-protected seams. It can also be used as a bonded wearing course for asphalt pavement, for higher durability and higher strength upon a concrete substrate, and in skate parks, as it is a very smooth surface. Polymer concrete has historically not been widely adopted due to the high costs and difficulty associated with traditional manufacturing techniques. Polymer concrete in the form of epoxy granite is becoming more widely used in the construction of machine tool bases (such as mills and metal lathes) in place of cast iron due to its superior mechanical properties and a high chemical resistance.

Mechanical properties and behavior High compressibility, tensile strength and flexibility, along with greater durability characterize polymer concrete. Compared with Portland cement concrete, the most common concrete type utilized in construction, polymer concrete better bonds to steel materials and other concrete materials. In polymer concrete, the polymer binders that are central to the composition exhibit a low elastic modulus making it far more flexible than traditional cement concrete that contain mineral binders exhibiting high elastic modulus. The rapid polymerization of polymer-based concrete enables greater ability to repair structural issues.

Thermal and chemical properties The thermal expansion coefficient of polymer concrete is approximately twice that of traditional cement concrete. However, the combination of a low elastic modulus and a high thermal expansion coefficient induces interfacial shear stresses. In high temperature environments, the elastic modulus of these polymer matrices are greatly reduced so this must be considered in structural applications. In low temperature environments, there is good long-term durability with respect to freeze and thaw cycles. The low permeability of water in polymer concrete is attributed to the hydrophobicity of the polymers that compose the concrete. As a result, polymer concrete is far more suitable for chemically aggressive environments compared to traditional cement concrete.

Specifications Following are some specification examples of the features of polymer concrete:

Sustainability Contrary to traditional cement concrete, polymer concrete is posited as a sustainable alternative as it incorporates recycled aggregates, industrial by-products, and waste within its composition. The incorporation of these materials extends the life of the concrete through greater resistance to environmental degradation. The binding agents in polymer concrete are more expensive than the mineral binders in cement concrete.

References

Further reading Mehta, P. Kumar; Paulo J. M. Monteiro (2013). "12.7 Concrete Containing Polymers" (PDF). Concrete: Microstructure, Properties, and Materials. McGraw Hill Professional. p. 505to510. ISBN 978-0-07-179787-0.

External links

Worked examples

Example 1 — a first encounter with Polymer concrete

Start with the simplest possible case. Write down what Polymer concrete claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In chemistry, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Polymer concrete before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Polymer concrete ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Polymer concrete

In research: Polymer concrete appears in chemistry research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Polymer concrete in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Polymer concrete is common in secondary-school and first-year university syllabi. It links to neighbouring topics Concrete, Pavements, so understanding it makes those chapters shorter.
In everyday life: Look for Polymer concrete outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

How to study Polymer concrete in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Polymer concrete means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Polymer concrete out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Polymer concrete in simple terms?

Polymer concrete is a type of concrete that uses a polymer to replace lime-type cements as a binder. One specific type is epoxy granite, where the polymer used is exclusively epoxy.

Why does Polymer concrete matter?

Because it connects several chemistry ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Polymer concrete?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Polymer concrete.