safety of buildings
There are many factors, both overt and covert threats to human life and health.These include a negative impact of hazardous substances belonging to the building materials, the risk of fire, partial collapse or destruction of the building.Therefore, taking care of the construction of safe houses should be integrated.Consider the most common threat, and some aspects of the construction of secure facilities.
According to studies, the concentration of toxic substances in closed areas in 1.5-4 times higher than outside the building.At the same time a person spends in the room an average of 19 hours a day.For the population of the major cities of residence time in the fresh air is reduced to one and a half hours a day.
heavy metals, carbon monoxide, the products released during decomposition of plastics - all present in the building of about 100 chemical compounds, in varying degrees, represent a threat to human health.In particular, these include substances
There are several sources of pollution.Among them - household chemicals, dust, gas stoves, micro-organisms and are one of the main construction and finishing materials, including a variety of polymers, wallpapers, paints and concrete.
list of materials that meet environmental standards, formed by the State Committee for Sanitary and Epidemiological Surveillance, but, in practice, developers are not always guided by them in their choice.Experts estimate that about 50% of all finishing materials on the market, do not meet sanitary requirements.
This category includes many polymeric materials that are widely used in the second half of the last century.Today polymers are used for the walls and floors, as sound-proof materials, etc.Most isocyanates are toxic, including some kinds of foam that emit harmful substances when heated.When choosing polymeric materials should be guided by the provisions of SanPin 126.96.36.1999-99 that establish sanitary requirements and regulate the scope of the polymers.In addition, make sure you have the sanitary-epidemiological conclusion, confirming compliance.
In general, there are several key requirements to be met by safe in terms of environmental materials used in the construction and decoration of buildings.In particular, they should not create a specific smell after putting the building into operation, to stimulate the development of micro-organisms and accumulate on the surface static electricity and have a negative impact on the indoor climate.
certain dangers may be construction materials with increased radioactivity.Typically, raw materials for their production are natural materials which contain microimpurities isotopes of uranium, radium, thorium and potassium.Increased radioactivity many different minerals, such as quartz diorite and granite, as well as sedimentary clay.For this reason, all the materials composed of natural minerals must be concluded by radioactivity.It should be remembered that the concentration of radioactive elements in building materials derived from the use of such raw materials, low and conventional dosimeter measurements rarely show radiation levels in excess of natural background.
main threat to the organism is associated with radon - a gas that comes from the decay of radionuclides.His progeny have the ability to condense and be deposited on the tiny aerosol particles, making them radioactive.Settling on the surface of the upper respiratory tract, the particles create a source of alpha-irradiation of cells that contribute to the development of cancer.
Thus, for the construction and decoration of buildings need to choose materials with a low content of natural radionuclides whose radiation complies with the "Radiation Safety Standards" (NRB-99) and the requirements of GOST 30108-94 "Building materials and products.Determination of the specific effective activity of natural radionuclides. "
One of the most significant threats to the people in the building is the possibility of fire, so the construction of buildings must be compliance with the fire that set the Technical Regulations on fire safety requirements and set of rules governing certain aspects of fire protection.
effective fire protection system consists of elements of active and passive protection.The latter include space-planning decisions, contributing to the localization of combustion, reducing its intensity and duration.First of all, we are talking about dividing the building into fire compartments with fire-resistant barriers.The area of the fire compartment should not exceed 2,000 square meters for residential buildings and 2,500 square meters - for other types of buildings.In addition to the horizontal division, with the help of fire walls in high-rise buildings by vertical zoning: at the height of the fire compartment should not exceed 50 meters (16 floors).
essential element of passive protection is a device refractory barriers between rooms of various fire hazards, as well as branch premises from the rest of the building.
even more stringent requirements for space-planning decisions in the design of high-rise buildings, for example, limit the height of the premises in which the fire fighting difficult, the number of elevator shafts, crossing the borders of fire compartments, the separation from the elevator lobbies adjacent rooms of fire barriers.
important role played by the design of evacuation routes people.Emergency exits must open the way to nezadymlennye staircases leading to the outside.Stairwells and fireproof area, in particular in high-rise buildings, are additionally protected against fire and smoke, and emergency exits are equipped with fire doors.
addition to the components of passive protection, guarantee the safety of people in the building it is the active protection system, whose function is to alert against fire, smoke removal, localization of the source of fire and fire-fighting.The first element is the active defense of the fire alarm.The system detects the source of fire by sensors reacting to the rise in temperature and smoke.After that, the signal enters the control.The most effective is the alarm that tells the coordinates of a fire - evidence of what exactly the sensor signal has been received.
Typically, fire alarm system integrated with the fire extinguishing system, which is automatically activated after the signal is sent to the console.Today's decision is Sprinkler systems, spraying microdroplets of thickness less than 200 microns.This produces a water fog that significantly increases the rate of heat absorption from the combustion gases and flame, and also displaces oxygen from the combustion zone.There is almost instantaneous source of fire localization and attenuation of the flame.Compared to traditional systems, water mist fire suppression eliminate the need for a smaller amount of liquid and quickly deal with the fire.In addition, their application is greatly reduced water damage.
major risk is the smoke that limits visibility and contains toxic combustion products, causing poisoning.For example, during the combustion of materials based on polystyrene allocated pungent suffocating smoke which comprises toxic substances - carbon dioxide and monoxide, hydrogen cyanide, benzene, nitrous oxide and others, therefore, be selective when regarding their selection and use.During the construction of safe houses and public buildings necessary to create an effective system of automatic smoke that starts as soon as the alarm is activated.It opens a mine to remove smoke and includes backwater of fresh air on the escape routes.As a result, the concentration of carbon monoxide from the vicinity of the fire is reduced, and the time required to evacuate people from the building increases.
In modern intelligent building components of the active fire protection is often integrated with the security system.The latter may include access control and surveillance.All information from external devices - cameras, sensors, electronic locks - goes to a single control that lets you quickly eliminate any threat - from fire to unauthorized entry into the building.
Another threat in case of fire is the possibility of the collapse of a building or its parts exposed to extreme temperatures.Therefore, the materials used in the construction of bearing and protecting designs, as well as floors and roofs of buildings, special requirements.For example, at a temperature of 150 ° C microcracks arise in reinforced concrete, and heating to 380 ° C leads to a complete loss of strength.An effective way to protect concrete structures from fire is to install fire protection systems on the basis of non-combustible stone wool, which ensures the required fire resistance.
important aspect of protecting buildings from fire and collapse - flammability of thermal insulation materials used in the creation of multi-layer construction of the walls and facade systems.For example, insulating materials based on expanded polystyrene, according to the mark, classified as T1-T4 (flammable and nonflammable materials) and ignited at a temperature of 220 ° C to 380 ° C.This imposes severe limitations on their use in buildings.Another insulating material - glass wool - may refer to a class of non-combustible in the event that its density is less than 40 kg / m3.It is not enough when the insulation is exposed to considerable stress.Unlike other types of insulation insulation based on stone wool is capable, without melting, withstanding a temperature of about 1000 ° C and provides fire resistance up to 4 hours.
In frames of many modern buildings are widely used bearing metal structures, which may also be subject to deformation and destruction by fire.The fact that under the influence of high temperatures worsen the mechanical properties of the metal, and when heated to 500 ° C metal structure completely loses its bearing capacity.
to protect metal structures from the effects of high temperatures developed several solutions.The most effective of them, provides fire resistance up to 4 hours - fire protection system ROCKWOOL ROCKFIRE.Its main component is a slab of stone wool, which, thanks to its properties, can effectively protect materials with a low fire resistance.Besides protecting against fire, this material has high thermal insulation properties.
In connection with the development of high-rise buildings is a pressing problem of protection against progressive collapse that occurs when the individual load-bearing structures damaged by fire, explosion, defective construction materials, etc.
The main safety measures include the development of design-planning solutions of buildings, taking into account the possibility of an emergency situation, ensuring a continuous designs, as well as the use of materials and solutions that enable development in structural elements and connections of plastic deformation.In general, anti-collapse of any building based on educated design decisions, use of quality materials and strict observance of technology installation.The error at any stage reduces the effectiveness of the measures taken.
Summing up, it is necessary to note once again that the concern for the safety of people who will be in the building, should be integrated.A large number of threats calls for implementing protective measures at all stages of construction - from design, selection of building materials and techniques to assess the quality of work performed.Only by using this approach, you can build a truly secure building.