Heat & Mass transfer question: If you investigate a radioactive material, you wo

Question

Heat & Mass transfer question:

If you investigate a radioactive material, you would need to estimate the volumetric rate of heat generation due to radioactive decay in an overall analysis. Another heat generation possibility would be “curing heat” released when a freshly-poured slab of cement is setting. Explain how the heat generation resulting from concrete being cured can be used advantageously during winter seasons.

Recall: Consider a slab of thickness, L, whose steady-state temperature on its left surface is TL, and whose steady-state temperature on its right surface is TR. The general form of the heat conduction equation is:

Explanation / Answer

Contractors nowadays have many improved concrete designs and pouring methods and can work well under any circumstances. They can advantageously use the heat generation from concrete pouring during winter seasons. During winter the temperature increase the length of cure time. Concretes poured in cold weather periods will have higher than ordinary ultimate strengths and better long term durability. This is because the contractors tend to keep the differential between a,bient air temperature and concrete temperature as low as possible.
Enclosures can be used to protect curing concrete from wind. Precautions like insulation are done in necessary areas to protect the concrete pored. The correct temperature for the mix is selected , aggregates and cement are added to hot water to ensure concrete is suitable for weather condition.
More cement is added to the mix to provide additional heat during hydration. For higher heat generation and high early strengths better cements are used.
Heated shelters should be used for the pour areas. These help trap the heat generated in the pour area and eases the setlement of the concrete. The heat produced from hydration of cement helps protect the concrete from freezing and provides a more favourable curing temperature. The insulation added helps trap the heat and allws it to achieve required strength. So cement with more heat of hydration production is used in winter condition.

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