Fresh concrete is particularly vulnerable to frost because the water in the mix can freeze and expand, causing the concrete to crack and weaken. When fresh concrete is exposed to freezing temperatures, the water within the mix can turn into ice, leading to internal pressure and potential damage to the concrete's structure. To prevent this, it is important to protect fresh concrete from freezing temperatures by using insulating blankets, heating systems, or other methods to maintain a suitable temperature for curing. Additionally, using air-entrained concrete mix can help improve the concrete's resistance to frost damage by creating tiny air bubbles that can accommodate the expansion of freezing water. **

Yes, it is possible to produce exposed concrete with lightweight concrete and expanded clay aggregates. Lightweight concrete is made by replacing the traditional heavy aggregate (such as gravel or crushed stone) with lightweight aggregates, such as expanded clay aggregates. These lightweight aggregates can still provide the necessary strength and durability for exposed concrete applications. Additionally, the use of expanded clay aggregates can result in a lighter weight concrete, making it easier to handle and transport. Overall, using lightweight concrete with expanded clay aggregates can be a viable option for producing exposed concrete. **

No, fresh concrete should not be placed on damp, smooth concrete that was poured the day before. This is because the moisture from the existing concrete can interfere with the hydration process of the fresh concrete, leading to poor adhesion and potential cracking. It is important to ensure that the existing concrete is properly cured and dried before placing fresh concrete on top of it to ensure a strong and durable bond between the two layers. **

No, fresh concrete should not be processed on damp, smooth concrete that was poured a day ago. The existing concrete needs time to cure and harden properly before any additional concrete is placed on top of it. Placing fresh concrete on damp concrete can result in poor adhesion, cracking, and other structural issues. It is important to follow proper curing and placement procedures to ensure the integrity and durability of the concrete. **

To produce 1m³ of rammed concrete, approximately 25 bags of ready-mix concrete (40 kg each) are needed. This calculation is based on the typical ratio of 1 bag of ready-mix concrete per 0.04m³ of concrete. Therefore, for 1m³ of rammed concrete, 25 bags would be required. **

To apply concrete on concrete, the existing surface must be clean, free of debris, and properly moistened. A bonding agent or primer should be applied to the existing concrete to ensure adhesion. The fresh concrete mix can then be poured or pumped onto the existing surface and spread evenly using a screed or trowel. It is important to properly cure the new concrete to prevent cracking and ensure a strong bond between the two layers. **

Yes, it is possible to pour new concrete over old concrete as long as the existing concrete is in good condition and properly prepared. The old concrete should be clean, free of any loose debris, and roughened to provide a good bonding surface for the new concrete. Additionally, a bonding agent may be used to ensure a strong bond between the old and new concrete. It is important to consult with a professional to assess the condition of the existing concrete and determine the best approach for pouring new concrete over it. **

For setting lawn edging stones, garden concrete would be the better option. Garden concrete is specifically designed for outdoor use and is more durable and weather-resistant than concrete screed. It also has better adhesion properties, making it more suitable for securing the edging stones in place. Additionally, garden concrete is often formulated to be more resistant to cracking and shifting, which is important for maintaining the integrity of the lawn edging. **