The sole difference between 2B and 2A is that the 2A has 10% limestone dust mixed in with the stone and thus compacts better. 2B is a clean crushed stone with a 3/4" average size. When attempting to bridge over moist soil regions, this material is employed for drainage work and roads.
Limestone is the main ingredient in mortar; if you substitute sand or some other type of rock for part of the limestone, the quality of the mortar will change. For example, if half the limestone in a recipe is replaced with sand, the mixture will be less durable. This is because the calcium carbonate in limestone forms an acid when it comes into contact with water, which helps break down the other ingredients in the mix.
If you want your driveway to last longer, use 2A rather than 2B. The limestone in 2A adds weight to the gravel, which helps the gravel stay in place and not get washed away by rain or traffic. Without limestone, the gravel can wash away at its edges where it meets the driveway or sidewalk, leaving a trail behind it for others to walk in. This is called "scratching" the pavement and can be difficult or impossible to repair if left untreated.
The presence of limestone also means that 2A is able to absorb some of the alcohol from car exhaust systems, which may help reduce vehicle emissions.
When a firm, compacted basis is required, 2A MODIFIED is often employed. Driveways and beneath sheds are two examples of applications. 2B STONE is utilized in areas where drainage is required. Perforated pipe, for example, can be used to reduce frost heave and cracking in concrete. It also allows water to evaporate more quickly.
Modified means that some asphaltic materials are modified with additives to improve their performance. For example, polymers may be added to modify the bitumen's viscosity so it can be sprayed like paint. These polymers are then removed during preparation of the material for use.
Stone is a natural rock. As such, there is no standard type of stone used in driveways. The type of stone used will depend on what look you want to achieve with your driveway. If you want a traditional looking driveway, then using a fine-grained stone such as flagstone or slate would be appropriate. If you want a modern looking driveway, then using large rocks instead might be better suited. The key here is that you need to select a stone that fits with your home's exterior style.
As mentioned, 2B Stone should be used in areas where drainage is required. This is because it has perforations which allow water to flow through easily. Without these holes, water would accumulate below the surface of the driveway causing erosion and potholes.
How much is a ton of 2B stone worth in this manner? The price of Limestone-2B is $23.50 per ton. $2.99 for a 50-pound bag A ton of 2B stone covers how much ground?
|Coverage (Square feet)||400||sq ft|
|Estimated amount (Pounds)||5,951||lb|
|Estimated amount (Tons)||2.98||ton|
Type 2 MOT, like Type 1 MOT, is an authorized granular subbase material consisting of crushed stone with a size of 40 mm down to dust. The distinction is that Type 2 MOT has more dust than Type 1, as it is made up of fewer angular aggregate sizes (also known as scalpings). The result is that Type 2 has better traction than Type 1 for vehicles with high ground-clearance and those who drive on rough roads.
Type 2 MOT is used in the same ways as Type 1 MOT. However, because it has better traction, drivers may want to use less of it or mix it with other types of subbases to achieve their desired performance level.
The Type 2 designation comes from its original production method which involved screening out smaller rocks from a mine pit before refining the product into sand and gravel. Today, some Type 2 materials are produced by hand at specialized facilities using quartzite, granite, and other similar rock sources. These materials are then mixed with a binder and screened to produce the final product. Other Type 2 materials are manufactured using industrial processes that produce extremely fine particles that do not require further processing such as air classification. These products can be used as-is or combined with other materials during application.
Type 2 MOT is available in the same colors as Type 1 MOT but with the addition of black.