Why was ash added to the mortar in masonry before

Some time ago, ash was an integral part of a brick mortar. In most cases, this was due to elementary savings in cement. I must say that its beneficial properties are used in construction to this day.

Ash is used as a substitute for sand, not only in the manufacture of mortars for masonry furnaces, but also in the manufacture of bricks. Very popular compounds with the addition of fly ash. It is an additive that not only saves other components of the solution, it also plays the role of a plasticizer. Thus, the solution is more plastic, it has an increased water retention capacity. The best indicators in this regard are fine-grained ash, which is collected from the last fields of electrostatic precipitators.

In some masonry mortars, the addition of ash is acceptable as an alternative to fine sand. Such a composition can be used with standard masonry, including for the construction of walls made of massive elements. The use of such formulations is limited to the time of year. At low temperatures, there is a slow heat during curing of the solution.

If we talk about cement mortars, the most suitable concentration of ash is 100-200 kg / m3. If there is a fine-grained ash, it can be used instead of part of the cement and sand. Coarse ash is used as a substitute for a small proportion of sand, while the volume of cement should remain unchanged.

Many masters have already noted that when using fly ash, cement consumption is reduced by about 30-50kg / m3. In this case, the solution itself becomes more convenient to use. If you try to replace all the sand with ash, you get a very large consumption of cement. In this case, it is recommended to add a little lime dough to the solution. It must be borne in mind that then the risk of structural deformation increases due to shrinkage.

If cement-lime mortar is made, a small volume of cement, lime or sand can be replaced with ash. Without sacrificing strength, you can save 30-50 kg of cement or 40-70 kg of lime dough per 1 m3 of mortar. When half of the lime is replaced with fly ash in a double volume, not only lime is saved, but also the strength of the solution increases.

Thus, the use of ash in the form of an additive to mortar is quite reasonable and has a right to exist. The main thing is to correctly calculate the proportions and take into account weather conditions.