Non-conventional curing methods in concrete construction

Cement serves as the primary binding agent in concrete, reacting with water to bind all ingredients together. When cement mixes with water, it generates heat known as the heat of hydration, which occurs due to high quantities of alite and tri-calcium aluminate. This heat generation is influenced by water content, fineness and curing temperature.

While the produced heat does not initially affect concrete hardening, it can reduce strength if not regulated during the hardening process. Water plays a critical role in controlling hydration, with curing being the process of providing water for proper hydration.

Both conventional and non-conventional curing methods exist. Non-conventional methods require special atmospheric conditions and are relatively expensive, making them less popular.

Non-conventional curing methods

1. Immersion method: The concrete product is poured into the curing tank. This fulfils the moisture requirement for products like precast tiles and pavers. However, this method presents challenges with test specimens and small units, requiring significant labour for handling.

2. Electrical curing: Alternating current passes through concrete between electrodes, buried or surface-mounted. Careful monitoring prevents moisture evaporation. Commonly used in cold climates, this method demands skilled workers and continuous oversight, making it economically unfeasible for many applications.

3. Infra-red radiation concrete curing: Infrared radiation increases concrete temperature for rapid strength gain, particularly effective for hollow concrete blocks. Operating temperatures reach approximately 90°C, producing faster strength development than steam curing without compromising structural integrity.

Conclusion

Non-conventional techniques require special attention and are employed only in specific situations. Proper curing ensures adequate concrete strength, inadequate curing produces weaker concrete with diminished performance.