What Is Soil Cement?
Soil cement is a mixture of aggregate, cement and water. These three compounds are mixed together. Not only is this mixture affordable due to the low cost of materials, but it is also strong and durable. Soil cement is most commonly used for parking areas, streets, roads, airports, etc. Due to this material’s low cost and robust nature, it has become the most popular option in the construction industry. In fact, a bituminous surface is placed over the soil cement. This layer is a thin surface treatment involving liquid asphalt. Let’s take a closer look at relevant information pertaining to soil cement.
The foundation must be strong for building pavements and roads. The material has to withstand years of repeated traffic flow. It also has to be reliable and dependable. The most durable and reliable foundation is soil cement. Soil cement works well to support traffic loading.
The Process of Soil Cement Building
Prior to any construction in a specific area, tests are conducted on cement content, water requirements and compaction of soil. Requirements must be met before the soil cement process can take place. Tests are rigorously completed by the laboratory. In fact, throughout the process, the analysis will be referred to verify quality. This analysis is important and the very first step to creating viable soil cement. All results have to be accurate and in line with standards. For example, the mixture must have adequate durability or else there will be problems later on. To avoid potential dangers and further work, tests must be completed. No one wants a driveway replaced given how much they cost to install.
There are two different ways soil cement can be mixed. It can be mixed in a central mixing plant or in place. If borrowed materials are involved in the process, central mixing plants are used. Granular materials are used due to their ease of mixing, handling and low cement requirements. The most common type of mixer used during this stage is a pugmill type. Once the mixture of soil cement is complete, it is transferred to the job site, where it will be spread on the subgrade.
Once this is accomplished, curing and compaction procedures are used. The following four steps are taken for mixed soil cement construction.
- Spreading cement
Once the correct quantity of cement is applied to the in-place soil, a few materials are mixed together. This includes the soil, cement and water. Once the materials are mixed together with the right consistency, they are tightly compacted. The compaction process does not require special equipment. The only tools needed for this step are different types of rollers. This will all be based on the soil type. Once finished, this mixture will be permanently cemented at high density. As a result, the risk of deforming under traffic is not present with hardened soil cement.
Contractors that are bidding on soil cement understand construction will be smooth sailing for the most part. Weather delays will be rare and infrequent. Furthermore, the need to rework completed sections will be unnecessary. Certain soil cement applications require micro-cracking.
The final step in this entire process is known as curing. Curing prevents evaporation of moisture. This will ensure the highest level of strength development through the process of cement hydration. As mentioned prior, a coat of bituminous material is used. This prevents moisture loss.
In the traditional method of construction, all poor soil would have to be removed. It would then be replaced. Alternatively, a thicker pavement would be required as well. If poor soil is treated with cement, the need for a thicker pavement can be eliminated in most cases. Certain soil conditions can pose issues throughout the construction process. They include compaction issues due to moisture content and insufficient soil/cement content. The mixing process must be timely and completed in the right order. The material must be uniformly mixed.
Why Choose to Use Soil Cement?
There are a few reasons why you may choose to use soil cement over other driveway material types. Soil cement allows granular-based pavements to be saved and reclaimed. First and foremost, this method is economical and efficient. Secondly, the costs for handling and hauling are significantly reduced. The reason is due to 90% of the necessary material already being present. In fact, waste materials and granular materials are suitable for soil-cement. These materials come from gravel pits and quarries. This allows higher-quality materials to be conserved for alternate purposes.
It is agreed amongst highway engineers that soil cement is an overall great solution. It is low cost and highly durable. The process of constructing it is fast. It has become a very popular option.
What is The Performance of Soil Cement?
The thickness of soil cement can be less than its granular counterpart for carrying the same amount of traffic over the subgrade. The reason for this is because soil cement is far stronger, more rigid and distributes over a broad area. Granular bases are not as strong as soil cement. Soil cement is well-known to resist rain, cold and spring-thaw damage. In fact, soil cement is so efficient that old pavements in many parts of the world are still providing service with low maintenance costs. Interestingly, the strength of soil cement enhances with age. According to specimens taken from older roads, the soil cement was up to four times stronger than when first constructed.
The Cost of Soil Cement
Soil cement is far more economical than granular base pavement. Generally, soil cement will be more cost-effective for equal load carrying. Soil cement even beats out other “low cost” pavements. Reusing materials that are already present as well as borrowing materials keeps the price low. There is no cost to haul. Therefore, time and resources are saved as well.
How Soil Cement Pavement Is Used
The uses for soil cement pavements include country roads, highways, roadways, parking lots, city streets, airports and facilities for storage. To be more specific, soil cement pavement can be categorized into three components. They include the following.
- CMS (Cement-Modified Soils)
- CTB (Cement-Treated Base)
- FDR (Full-Depth Reclamation)