Concrete dust can have negative effects on health when inhaled. The fine particles in concrete dust can irritate the respiratory system, leading to coughing, wheezing, and shortness of breath. Prolonged exposure to concrete dust can also cause chronic respiratory issues such as bronchitis or even exacerbate existing conditions like asthma. In addition, concrete dust may contain harmful substances such as silica, which can lead to lung diseases like silicosis when inhaled over time. Therefore, it is important to take precautions to minimize exposure to concrete dust, such as using proper respiratory protection and ventilation when working with concrete. **

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. **

It is not recommended to pour Styrofoam panels into concrete for a table project. Styrofoam is not a suitable material to be embedded in concrete as it can break down over time and compromise the structural integrity of the table. It is better to use materials like wood, metal, or glass for a table project that will be durable and long-lasting. **

It is not recommended to pour Styrofoam boards into concrete for a table project. Styrofoam is not a suitable material for this purpose as it can melt or disintegrate when it comes into contact with concrete. It is better to use materials like wood, metal, or glass for a table project to ensure durability and stability. **

It is not recommended to pour Styrofoam sheets into concrete for a table project. Styrofoam is not a suitable material for use in concrete as it can break down and deteriorate over time, compromising the structural integrity of the table. It is better to use materials specifically designed for concrete projects to ensure the durability and longevity of your table. **

It is unclear whether the concrete belt was poured with the wrong concrete based on the information provided. To determine if the wrong concrete was used, further investigation would be needed to compare the specifications of the concrete used with the requirements for the project. Factors such as strength, composition, and curing methods would need to be considered to determine if the concrete used was indeed incorrect. **