The biggest challenge of making concrete buildings is that with time the material dries and cracks. Self-healing solutions have solved this by applying bacterial biotechnology.
BioCement is a natural, carbon-neutral process which is useful for improving the quality of the soil. It is based on the stimulation of native soil bacteria for cementing the soil particles together through a process known as Microbial Induced Calcite Precipitation (MICP).
BioCement Technologies Inc., a company based in the U.S, manufactures it and aims to provide microbial soil engineering solutions.
It comes in a dry powder that should be mixed in water. This nutrient-rich solution is then fed to native soil bacteria, which grows in proportion to the number of nutrients and helps in cementing the soil together.
This powder can be used for remediation of heavy metal contamination in soils, unpaved roads, for controlling the hydraulic conductivity of soils and also in combating the soil liquefaction.
The basic process of BioCement
Nutrients are applied to the soil for growing the native bacteria population. The bacteria ingest the nutrients and hydrolyze the urea component in the presence of water to form ammonium and carbonate ion.
Nutrients are re-applied to the soil, by adding calcium chloride. In the presence of calcium ions and soil particles, the carbonate ions react spontaneously with the calcium ions to form calcium carbonate, the cementing agent used for binding the soil particles together. BioCement powder can be used in liquid form and can be applied through a variety of means including spray bars, drip lines, injections, hoses, and high-powered pumps.
Advantages of BioCement
1. BioCement increases the shear strength and unconfined compressive strength in the wide range of soils, including large-grained sands to fine-grained silts.
2. Since it is a carbon sequestering process, it is eco-friendly and helps to store carbon which could otherwise enter the atmosphere
3. BioCemented soils are self-healing! It means that if the bonds between soil particles are broken, the bacteria in the soil will self-repair.
4. They fill in the empty space between soil particles, which means the volume of the treated soil does not increase. Due to that, it can be used around existing infrastructure without causing damage.
5. BioCement can help in customizing a range of soil strength and permeability.
6. This process is a natural part of the environment. The bacteria used are naturally occurring in almost all soils and limestone (or calcite) makes up a third of the Earth’s crust.
For more information, you can visit the official site: BioCement.Inc