Concrete forming on residential
In recent years, the general scope of individual construction, the growth of requirements for the architectural appearance and quality of houses, professional design have led to a wider use of concrete in residential construction.
In this article, I would like to draw the attention of developers to new opportunities that have appeared recently in this area, new technologies, materials, and methods. Earlier, concrete was traditionally used for the construction of foundations and basement floors, but now more and more often in individual construction, concreting is also used to erect walls and ceilings, i.e. the whole box of the building. Obviously, the reasons for this are as follows: – improvement of concreting technology, the appearance of effective formwork; -availability of ready-mixed concrete mixtures and special equipment for the delivery and laying of concrete; – complex architectural solutions that dictate the use of reinforced concrete for their implementation; -price factor; -high pace of construction; -appearance of effective materials for additional thermal protection of concrete structures and their decoration.
Fundamentally different are two ways of erecting buildings using the method of monolithic concreting – into panel formwork and in permanent formwork. In connection with various technological features, primarily, with the turnover of formwork, the first method is most common and expedient for the construction of multi-storey buildings, and the second one is for residential construction. Consider some of its features. The essence of the method is that the elements of the building structure are formed from the formwork, which is filled with concrete. After its setting, the formwork is not removed, as usual, but remains, performing decorative or heat-insulating functions.
There are currently two types of fixed formwork on the market. The first is a fairly large hollow blocks, of which walls and floors are mounted. After installation, they are filled with concrete mortar. Foamed polystyrene, wood-cement mixtures, expanded clay, slags are used as material for blocks. Thus, the concrete core provides structural strength, and the light shell of the blocks provides the necessary thermal insulation. Unconditional advantages include simplicity and high speed of installation, excellent thermotechnical properties of such structures, low requirements for the qualifications of the builder, which attracts private developers. The entire construction process is reminiscent of a game with the LEGO constructor. However, the disadvantages are poor bearing capacity, the need to have many different types of blocks for the implementation of the architectural elements of the building, high fire hazard (polystyrene), difficult additional surface finish of the finished wall.
1This technology has several advantages over block technology. This is an increased bearing capacity, the absence of a variety of prefabricated elements (blocks), wide architectural capabilities, the required thermal insulation and fire protection are easily achieved. The most famous manufacturers of fixed panel formwork elements are VELOX (Austria) and Eltomation (Holland). Analysis of modern low-cost construction technologies available in Russia allows us to recommend that individual developers pay special attention to VELOX formwork. Recall briefly the essence of the method. Wall formwork is collected simultaneously along the entire contour of the house on a flat, even surface, which may be the basement basement slab, the basement or floor overlap. The wall is assembled in layers of narrow (500 mm) plates with a thickness of 35 mm, fastened together by steel ties. Screeds simultaneously calibrate the wall thickness and prevent the formwork from bursting during concreting. The outer formwork plate is installed with a pre-glued insulation, the thickness of which is determined by the requirements of thermal insulation. Depending on the design of the house, fittings can be installed in the formwork gap. Concreting of each floor is usually carried out in several stages. After installing the first row of formwork (500 mm high) and checking all sizes about.
1. Material, its physical properties. The plate is made by semi-dry pressing of wood chips, pre-coated with cement. The finished plate is non-hygroscopic, not subject to swelling and decay, porous, has good strength, developed surface, environmentally friendly, easy to process. The porosity of the slab is important when concreting, as excess water is removed almost immediately and concrete does not shrink, and during operation, a wall with such a coating regulates humidity well due to its good sorbing ability. The developed surface of the plate provides good adhesion to any finishing compounds.
2. Easy to install. Dry installation of the formwork allows you to control the quality of the assembly well, makes it easy to correct errors, does not require highly qualified builder. The combination of an external plate with a heater of various thicknesses allows any thermal insulation to be provided, while the wall structure and installation method are not changed. The use of special screeds increases the accuracy and quality of installation. Simple constructive solutions for interfaces with roofs, floors, stairs, balconies.
3. Architectural capabilities. The technology allows you to implement any architectural solutions – arches, arches, curly openings, inclined walls, volumetric decorative elements, etc. Moreover, everything from stairs to ventilation channels is made of one material. The nomenclature of materials required for construction is reduced by 3-4 times compared to other technologies.
4. Low cost. Since the basic materials are not exotic and inexpensive, this allows you to ensure the cost per square meter of the outer wall within $ 50 with good finishes and excellent thermal characteristics. The latter circumstance is especially important when operating a house and will provide additional cost savings. Reducing the range of materials helps to reduce costs due to transport and operational costs for their search and purchase. The low laboriousness of basic construction operations also saves on labor costs, and the simplicity of the technology allows the developer to refuse the services of expensive specialists and perform some of the work on their own without risking losing quality and time.
5. High quality housing. It is achieved through accurate assembly of the box at home, providing high thermal insulation, good finish. The environmental aspect is very important. There is a prejudice against the use of concrete in residential buildings. It is fully justified for prefabricated houses, as the high density of the factory-made concrete panel and its insufficient thermal insulation lead to condensation of vapors on the panel surface and the abundance of surfaces with different temperatures and humidity in the living volume. In our case, concrete is cut off from the living volume by a layer of slab with excellent heat-insulating and sorbing properties. And the external location of the insulation brings the dew point to the outer surface of the concrete core and the mass of concrete creates an additional temperature buffer when the outside temperature changes and increases the comfort of the room. In addition, the technology allows the use of light or porous concrete for pouring the core.
6. High rates of construction. The average time for the construction of one floor with an area of 100 square meters is 7-10 days by 3-4 people. However, it should be noted that after the completion of the box and the installation of the roof, it takes time (3-4 weeks) for the concrete to dry. Usually, during this period, they are engaged in the device of internal networks, and then proceed to finish. Thus, it is possible to completely complete the construction in one season. We hope that the listed features of the technology of cast-in-place concreting into fixed formwork will attract the attention of individual developers and will provide another opportunity to quickly, efficiently and inexpensively solve the problem of building a house that meets all modern requirements.
