Sometimes we have to remember school lessons in our adult life. It comes down to geometry. Concepts such as "volume", "surface area" are often recalled during repairs or summer cottage construction.
Let's remember how to calculate the cubic capacity of certain building structures or materials so as not to overpay for excess material on the one hand and not to stop the construction process to deliver the missing quantity on the other. In fact, there is nothing difficult in calculating the volume of basic geometric shapes. There are some peculiarities in calculating the volume of bulk materials, building materials, such as crushed stone, pebbles, as well as chopped firewood and firewood in logs or logs. But first things first.
How to calculate the cubic capacity of a flat building structure?
The formula for calculating the volume is universal:
V=H ∙ L ∙ B, m3
where:
H – concrete layer height (thickness), m;
L – structure length, m;
B – width, m.
The procedure for calculating the volume of a parallelepiped is shown in the figure.
Let's take a simple example first. Necessarypour a concrete porch of known dimensions, consisting of two rectangular steps. How to calculate the volume of concrete needed to make this structure?
For ease of calculation, it is convenient to divide the structure into two parts 1 and 2. Both of them are nothing more than parallelepipeds with known dimensions. The width of both parts is the same and is 1 m, the thickness is also equivalent - 0.2 m each. The length of the first (lower) step is 1.2 m, the upper - 0.8 m.
Upper stage volume:
V1=H1 ∙ L1 ∙ B1 =0.2 ∙ 0.8 ∙ 1. 0=0.16 m3
Lower stage volume:
V2=H2 ∙ L2 ∙ B2 =0, 2 ∙ 1, 2 ∙ 1, 0=0, 24 m3
The volume of the entire structure
V=V1 + V2=0.40 m3
The shape of some building structures seems very complex at first glance. But do not despair, because all of them, even the most complex forms, can be divided in this way into the simplest geometric shapes, find the cubic capacity of each separately and then summarize.
Foundations
Main types of foundations used in private construction:
- ribbon;
- pile;
- pile with grillage;
- slab.
A slab foundation is, as the name implies, a slab - a parallelepiped, the volume of which was calculated above. Recently, it has been steadily gaining popularity, with the right constructionhas phenomenal stability on difficult clay soils and loams.
Let's consider how to calculate the cubature of a strip foundation. The calculation algorithm is as follows: first, the perimeter of the foundation is calculated, which is multiplied with the width and height of the tape. An example of a strip foundation for a small building with dimensions in terms of 5 by 3 m in the figure.
Foundation perimeter:
Р=5 ∙ 2 + 3 ∙ 2=16 m
Then the volume of construction:
V=16 ∙ 0.4 ∙ 1.5=9.6 m3
And how to calculate the cubature of the base, consisting of cylindrical flooded piles? We calculate the volume of one cylindrical pile, shown in the figure, with a length of 2.1 m and a diameter of 0.26 m. So, the volume of the cylinder is:
V=π ∙ R2 ∙ H, where:
π – universal number equal to 3, 14;
R – radius of the circle, equal to half the diameter;
H – pile height.
In our example:
V=π ∙ R2 ∙ H=3, 14 ∙ (0, 26/2)2 ∙ 2, 1=0.111 m3
Since the foundation consists of several piles, the resulting value of the volume of one must be multiplied by their number.
Pile foundation with grillage is a symbiosis of the two types discussed above. A grillage is nothing more than a tape, below which piles are located. It is necessary to calculate the cubature of the grillage (tape), then the volume of the pile foundation and summarize the obtained values.
How much should I buy?
However, the owner does not careso much the question is what is the exact volume of a particular building structure, and how much and what materials need to be purchased. How to calculate the cubic capacity of crushed stone, sand and cement needed to fill a mold if its volume is known? Special tables developed by the builders will help with this.
Composition of components for the preparation of concrete grade 300 (foundation):
However, on the construction site, as a rule, they do not use scales, the following table is designed specifically for working with a concrete mixer:
Lumber
Such common lumber from timber as beams, boards, laths have a geometric shape of a parallelepiped, and it is not difficult to calculate the volume of each product separately. This concerns the calculation of the need for material for the construction of a greenhouse or gazebo frame.
However, it is difficult to imagine what the calculation of the required number of boards for the floor in the cottage will turn into if we calculate the location of each piece of wood and its volume. But then how? You can calculate the cubature of the board using a simple formula:
V=S ∙ h ∙ 1, 05 / 1000
where:
S – floor area of finished premises, m2;
h – selected floorboard thickness, mm;
1, 05 – crop factor.
Log cabins
Despite the rapid development of the construction industry, the annual appearance of new materials with first-class strength, thermal insulation and other properties, fromwooden log cabins and do not think to refuse. On the contrary, the construction of houses and baths from wood is only gaining popularity. Let's figure out how to calculate the cubic capacity of a log needed to build a log house.
Before the calculation, as a rule, the plan of the perimeter of the building is known, and hence the length of the logs. In order to calculate their number, you need to know the number of crowns, which depends on the height of the wall and the diameter of the round timber. In construction, not the entire height of the log is used, part of it “eats” the groove. This is clearly seen in the diagram.
Further, knowing the number of logs and their diameter, the calculation is done similarly to the calculation of the cubature of cylindrical piles.
Firewood
Although pipeline gas is slowly coming to the most remote corners of the country, wood heating, most likely, will not lose its relevance soon. Firewood most often recently brought ready, that is, sawn and chopped. But if they were brought in a box of cubic shape, meter by meter by meter, this does not mean at all that the customer has to pay for a cubic meter of fuel. The calculation is done for the volume of wood, not air. Consider how to calculate the cubic capacity of firewood purchased and delivered to the customer.
In fact, it is impossible to accurately calculate the cubic capacity of firewood, you can only roughly estimate how much fuel is in the body, stack, etc. To do this, the geometric volume in which the folded or dumped heating oil is located must be multiplied by a correction factor.
If the wood is stacked tightlyin a stack, this coefficient is 0.71-0.85, but the chopped ones, thrown into the body in bulk, occupy only 0.29-0.35 of the total volume.
Firewood trailer
But firewood is not transported in the right containers. How to calculate the cubic capacity of fuel delivered to the site in conventional transport. This is usually a body or a trailer with a slide. Well, let's calculate the volume of this slide. Let's imagine that firewood is in the back of a car with a rectangular shape, dimensions in terms of L by B and height H. Above the sides of the body rises a hill with a height of h.
The formula for determining the net volume of firewood in the back will look like this:
V=k∙L∙B∙(H + h/3), m3
L – body length, m, B – body width, m;
H – side height, m;
h - the height of the "hill" rising above the sides, m;
k – volume factor.
