How To Make Pervious Concrete

Summary

This video tutorial demonstrates the process of making pervious concrete, a durable and strong material that allows water to pass through. It contrasts with regular concrete by omitting sand, creating voids for water permeability. The basic mix involves three parts rock, one part cement powder, and water. The video emphasizes the importance of water quantity, suggesting a trial-and-error approach to achieve the right consistency. It also introduces 'perc top,' a product for a smooth and permeable surface. The video concludes by encouraging viewers to explore more about pervious concrete applications on their website.

Takeaways

• 🏗️ Pervious concrete is a durable and strong material that allows water to flow through it, differing from regular concrete by omitting sand to create voids.
• 🛠️ Large installations of pervious concrete may require special mix designs and equipment, but a basic mix can be made with three parts rock, one part cement powder, and water.
• 🌲 Any rock can be used, but smaller, cleaner, more angular, and uniform rocks are preferable for maintaining permeability and a smoother surface.
• 💧 Finding the correct water-to-cement ratio is crucial; too much water can make the concrete impermeable, while too little can cause the rock to loosen.
• 📏 For a basic mix, use 3 gallons of dry pea gravel, 1 gallon of loose unpacked cement powder, and 1 quart of water, adjusting based on the rock's moisture.
• ☀️ Mix the concrete in the shade and during cooler temperatures to minimize evaporation and maintain the correct consistency.
• 🧤 When mixing, start with less water than you think you need and add more gradually until the right consistency is reached.
• 🤲 To test the mix, squeeze a handful into a ball; it should hold together with a shiny cement paste, indicating the correct water amount.
• 🔄 If the mix is too dry, add a small amount of water and retest; if too wet, add more aggregates and cement.
• 🌐 Pervious Products offers a product called 'Perc Top' for a smooth and permeable surface and provides special mix designs for various applications.

Q & A

What is pervious concrete and how does it differ from regular concrete?

Pervious concrete is a durable and strong material that allows water to flow through it. Unlike regular concrete, which uses rock, sand, and cement, pervious concrete omits the sand, creating voids for water to pass through.

What are the special requirements for large installations of pervious concrete?

Large installations of pervious concrete require special mix designs and equipment to ensure the correct consistency and permeability.

Can pervious concrete be made without purchasing it as a packaged product?

Yes, pervious concrete can be made by mixing three parts rock, one part cement powder, and just enough water to hydrate the cement.

What type of rock is recommended for making pervious concrete?

Almost any rock can be used, but smaller, cleaner, more angular, and uniform-sized rocks are preferable for maintaining permeability and providing a smoother surface.

What is the recommended rock size for a basic mix of pervious concrete?

For a basic mix, 3/8 inch pea gravel is recommended and can be found at local rockery or landscape supply stores.

How does the moisture content of the rock affect the amount of water needed in the mix?

If the rock is wet, it will require less water than if it is fully dried. The correct water amount is crucial for the permeability and strength of the concrete.

What is the ideal temperature range for mixing pervious concrete?

The ideal mixing temperatures are above freezing but below 80 degrees Fahrenheit to minimize evaporation and ensure proper hydration.

Why is it important to mix pervious concrete in the shade and during cooler parts of the day?

Mixing in the shade and during cooler times helps keep the mix temperature cool, which minimizes evaporation before the concrete is placed and finished.

How can one determine if they have the correct water-to-cement ratio in their pervious concrete mix?

The correct water-to-cement ratio is achieved when the mix holds together in a ball, the cement paste has a shine, and the paste sticks to itself more than it does to your gloves.

What should one do if the pervious concrete mix has too much water?

If the mix has too much water, it will appear wet and slimy. To fix this, add more aggregates and cement to achieve the correct consistency.

What is 'Perc Top' and how does it relate to pervious concrete?

'Perc Top' is a product developed to provide a smooth and permeable concrete surface. It is an alternative to traditional pervious concrete mixes.