Temperature Control in Gravity Dam Foundation Treatment - Gravity Dams - Water Resource Engineering | Summary and Q&A

TL;DR

This video discusses the importance of temperature control in gravity dams to prevent cracks and damage.

Key Insights

• 😲 Temperature control is crucial in gravity dams to prevent cracking and damage.
• 👷 Pre-cooling of concrete materials can help lower the temperature before construction.
• 😎 Post cooling involves circulating refrigerated water through pipes embedded in the concrete.
• 😘 Restricting lift height, providing contraction joints, and using low heat cement also contribute to temperature control.
• 😲 Surface cracks caused by temperature variations can lead to water seepage and structural damage in gravity dams.

Transcript

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Questions & Answers

Q: Why is temperature control important in gravity dams?

Temperature control is crucial in gravity dams to prevent cracking and damage to the structure. Without proper control, temperature variations can lead to surface and interior cracks, allowing water to seep in and weaken the dam.

Q: What causes cracks in the interior of concrete blocks in gravity dams?

Cracks in the interior of concrete blocks are caused by the heat of hydration, which is released during the cement curing process. This heat leads to high temperature gradients between the surface and interior, resulting in cracking.

Q: How can pre-cooling of concrete be used to control temperature in gravity dams?

Pre-cooling involves cooling the aggregate, sand, and other materials used in the concrete manufacturing process. This helps lower the temperature of the concrete before it is placed in the dam, reducing the risk of cracking due to temperature changes.

Q: What is post cooling of concrete and how does it work?

Post cooling involves circulating refrigerated water through pipes embedded in the concrete of each lift in the dam. This helps cool down the concrete immediately after pouring and continues until the mass temperature reaches the mean annual temperature of the locality.

Summary & Key Takeaways

• Gravity dams are constructed using concrete, which has a tendency to shrink and expand with temperature changes.

• Without proper temperature control, cracks can occur between the joints of concrete blocks, leading to structural damage.

• Temperature variations can cause surface cracking, allowing water to seep into the dam and potentially weaken it.