Hello, my name is Jhonny and welcome to my blog, in this post you will learn many facts about cement that will help you use it well; For starters, it is a construction material par excellence that is used in practically all works and is a gray powder that in the presence of water has the power to harden, for example, when mixed with sand, it initially forms a soft paste that with the Over time it sets and hardens, and can be used, among other things, for example to render a wall or as a brick glue.

Cement is not a material that is extracted from a quarry, in general it is made up of several components, the main one being limestone; Limestone is ground, crushed and sieved and then other elements such as clays, slates and iron ores are added to obtain different properties and characteristics.

All these elements are put into an oven that cooks them at a temperature above 1,400 degrees and as a result of this, what is obtained is the base material called Clinker, this material is crushed again, sifted and with other additives among which is the plaster and what we know as cement is obtained

For many, cement and concrete are more or less the same, but let's make some clarification, cement is actually part of the concrete component, if we add fine additives to the cement, such as sand, for example, we obtain what we call mortar. ; and if we add a third element to the cement and sand, which would be coarse aggregates, gravel or stone, we obtain what is known as concrete, all these elements are mixed dry and the main component is added, which is water, which It is the catalyst, the water together with the cement cause these complex chemical reactions, which is responsible for hardening the other elements, the sand and the stone, and forming what is called a composite material.

One of the most used uses of cement is the plastering of walls and walls, but I am sure that in much of the Spanish-speaking world they will not know what I am talking about, in many places, the plaster is known as Jaharro, Thickened , enjarre or repellado whatever the name is, it is neither more nor less than a mixture made from cement and sand that is used to place on the walls or on the bricks.

There are two types of mixtures that are used as mortar and that have a cement base, one of them is waterproof mortar, also known as water-repellent plaster or waterproof plaster, a mixture that is no more than 5 millimeters thick and is made directly on the outside of the bricks to protect them from moisture.

There is almost a universal formula that is applied to this type of mortar, which consists of mixing one part of the cement with three parts of sand, and when I speak of parts, I am not speaking of weights, I am speaking of volumes. to be fine, it can be a shovel, a jar, it can be a bucket whatever you want but always using the same element as a measurement and this dry mixture is going to hydrate with water and a liquid water-repellent additive, a chemical that favors even more waterproof properties, this is done until the appropriate consistency is obtained that has to do with the use that we are going to give it, for example, in this case a plaster.

The second mortar that I mentioned to you is what is known as thick plaster, which is basically a layer that is no more than 1 centimeter, a centimeter and a half thick, that goes immediately over the water-repellent plaster, in the case of walls and exteriors or directly on the wall on raw brick in interior plasters.

This layer of mortar serves more than anything to level the irregularities of the bricks and serves to leave it as a final finish or to receive what we later use as a final finish, which can be stucco, plaster or hydrated lime.

The ideal proportion for a thick plaster would be, a quarter of cement, a part of lime and three or four parts of fine sand, in this case you will have seen that we add lime that is also a binder like cement, but it gives more plasticity to the mixture for its application and curing.

Many will believe that the more cement in the mix is ​​better, I risk saying no and this is on my account, I believe that the misuse of cement is one of the main reasons why the constructions of a few years here are so prone to the formation of cracks, adding more cement than necessary to the construction does not make it stronger, but on the contrary, it makes it more fragile, more prone to the formation of cracks, weaker in the face of movements, movements that have to do with With everyday issues setting aside what earthquakes are, for example, there are movements due to ground settlements, sudden changes in temperature or simply due to traffic.

Another very important thing is the handling that is given to the cement, because the cement has an expiration date and this information is very important, especially for those who are going to be large stockpiles of cement, who are going to buy large quantities to use in the months following, according to the cement manufacturers once this work should be used within one or two months maximum, and it will depend greatly on the humidity conditions at which it is stored.

In addition, regardless of the time that has passed since you bought it and you have it in the work, it is important that you bear in mind that when you open the bag of cement and detect that it has lumps, lumps that do not come apart easily when you press it with your hand, it is a clear symptom that the hydration process has already begun, that is to say, that the cement has been in contact with water and has begun to hydrate and harden, the basic recommendation despite the fact that you want to save what you want, do not use it, discarding it because it is a cement that has already begun to set will not have the same capacity or the same resistance.

Last but not least, the curing of the cement is a key and crucial point in the works because cracks can appear in some cement mixtures, and this basically occurs due to premature drying, because it loses water very quickly, due to the weather conditions, sun and winds; remember that it is a chemical reaction that needs water to take place and the excess of it will not harm you, quite the opposite.

I hope the information is useful when making a decision, do not forget to support me and we will read next time, bye.

All images including schematics, photos and models are mine