Mixed binder

For the production of mortar you need different binders such as B. the mixed binder .

The mixed binder is a hydraulic binder that contains finely ground trass , blast furnace slag or blast furnace slag as well as hydrated lime or Portland cement to stimulate hardening.

Mixed binder hardens both in the air and under water , as it is one of the hydraulic binders.

According to DIN 4207, its compressive strength is set to at least 15 N / mm² after 28 days.

Its use is limited to the production of mortar and unreinforced concrete ; other binders are used for other types of mortar or concrete.

Mixed binder is a mixed binder that can be mixed at the construction site or bought as a ready-made mixture at the hardware store (e.g. Varilith or Dorosol). Depending on the mixture, different compressibility or strength can be achieved.

use

Excavation

Mixed binders are used when excavated soil from cohesive soil is difficult to compact. In such cases, the excavated soil must be replaced by replacement material. This process is very expensive and comprises up to 80% of the construction costs on a sewer construction site, for example. The method provides for binding agents such as mixed binders, lime or cement to be added to the soil in order to make the soil more compactable.

When using mixed binders, make sure that no more than 1% binder is added to the excavated material, as otherwise excessive dust would develop.

mortar

See also : plaster and wall ties

With the right mixture of mixed binder, water and aggregate , water mortar is created, which hardens in the air as well as under water. The resulting mortar can be used for components that are outside or in the water.

concrete

The task of the binding agent in the concrete is to hold the aggregate in a fixed position. It closes any gaps between the grains and thus ensures low capillarity . If the binding agent is incorrectly mixed, voids are created between the aggregate ( called pores ). In this case there is a high capillarity, i. H. the hardened concrete absorbs more water than normal and can crack as a result. When there is frost, the bound water expands and the concrete can break. The water-cement ratio is decisive for backfilling . If this is too low, it is possible that the binding agent does not get into all the gaps and leaves air pores behind.