Curing time in summer is less than that in winter. Why?

While concrete sets, it gains hardness and strength as the process of hydration slowly spreads the entire body of material. Curing should be allowed to continue for several days before subjecting the new concrete to significant stress.

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What are the potential problems of excessive application of form oils?

The problems of excessive application of form oils are:

(i) It stains the surface of hardened concrete.

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How can release agent help to separate formwork from concrete?

There are generally two main types of form releaser: barrier type or chemically active type.

For barrier type (e.g. form oil), it creates a barrier between the form and the fresh concrete. However, the quick evaporation of diesel oils affects clean air.

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How does rain affect the freshly placed concrete?

Rain may affect the water cement ratio at top portion of freshly placed concrete provided that the concrete is not properly protected from rain. To substantially change the water-cement ratio of the concrete at the surface of the slab, external energy must be supplied to the system such as troweling passes with excess water on the concrete surface.

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What is the difference between release agent, form oils, form releaser, demoulding agent?

Release agent, form oils, form releaser and demoulding agent are materials for separating formwork from hardened concrete. Though they generally refer to the same meaning, there are slight differences among
these terms.

Release agent: Materials that contain ingredients which are chemically combined with cement.

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