cement and lime soil stabilisation

Cement has been recognised for some time as an excellent stabiliser for soils. The cement serves at least two purposes. First, the cement itself is a binder to increase strength of the compacted soil as it sets. Secondly, the calcium in the cement tends to undergo ion exchange with any ion- exchangeable clay present to reduce water absorption by the clay to a minimum.

ENDURAZYME AND CEMENT

Endurazyme has been used in the field with cement to get a uniformly blended and easily compacted soil mass. With this program, increased strength and stability can be achieved in the field.

Laboratory tests show increased unconfined compression strengths when the procedure is modified in keeping with the function of Endurazyme. Instead of the full 7 day moist cure normally followed with soil and cement cores, the cores should be pulled out of the moist chamber after 48 hours, allowed to air cure for at least 48 hours, then return to the moist chamber for the rest of the 7 day cure before testing. The percentage of cement can also be lowered in many cases using Endurazyme with no loss in strength. In many lab core tests, the use of Endurazyme with soil and cement cores reduced the cement content required to achieve a given strength by up to 50%, which is a considerable saving in cement.

ENDURAZYME AND LIME.

Lime can be a very useful chemical for reducing the Atterberg Limits of a soil, and in increasing the stability of the soil after compaction. To achieve the beneficial results the soil and lime must be mixed together in the presences of water. Without the water the reaction is negligible. The lime is not very soluble in water so intimate mixing of the ingredients plus considerable time is required. In addition, a large excess of lime over the stoichiometric quantity actually required. As a result of this factor plus the reaction involved, the final compact soil mass is usually less dense than it would have been had the lime not been used.

The use of Endurazyme can help achieve better mixing and better lime reaction in a lime stabilisation program. Preliminary data show that the amount of lime can be reduced when Endurazyme is added. As a result, the density drop is not as large and a more stable soil can be expected