Soil stabilization and strengthening of pavement layers using mix-in-place method
Ground improvement with lime was a common practice already about 2000 years ago. The first builders to use powdered lime to stabilize the ground on the road were ancient Romans. In USSR the first experiments of clayey soil stabilization were held in 1920s, and the experimental sites were built in 1950s. Nowadays, taking into account the growing transportations costs and lack or remoteness of quarries with suitable soil, the specialists of JSC “Tatavtodor” decided to use this technology. The first works of soil stabilization with lime were carried out on experimental site in 2010. In 2011-2012 the mix-in-place method of soil stabilization with lime became widely used by the company. Such technology is 2.5 times less costly than replacement of the hydromorphic soil with the suitable ground (considering transportation of the soil from quarry 5 km away). In 2010-2012 the company had stabilized more than 370 thousand sq. m. of the road using this technique.
Construction of the base-course of the road stabilized with concrete using mix-in-place method is practiced as a more cost efficient alternative to the macadam road bedding. Such technology was first used by the secialists of the company in 2012 on site “Aktanysh-Poisevo-Kuziyakino in Aktanyshskiy district of the Republic of Tatarstan”, and later – on sites “Chistopol-Aksubayevo-Nurlat-Chuvashskoye Yenoruskino-Tarkhanka in Aksubayevsky district of the republic of Tatarstan” and “Laishevo-Kurmanakovo in Laishevskiy district of the republic of Tatarstan”. One of the advantages of this method is less technical operations in construction of the road base-course. The technology of simultaneous construction of sand-and-gravel mix underlayer and cement-bound base-course using mix-in-place method reduces the price of 1 sq.m. of the road by an average of 15-20%. For the year 2012 about 200 thousand sq. m. of the base-course was built.
The operations and equipment used in both methods are much the same – on the previously shaped base the cement or lime is spread by trailed Streumaster SW 10 spreader with automatic electronic dosing system, mixed by «САТЕRРILLAR» RМ-500 (350V) recycler with addition of water, then the matter is shaped once more and compacted.