Building Template 2

The consumption of steel and bamboo timber for building formwork is huge in China

Building formwork is an important tool in concrete structure construction. Experts point out that in the cast-in-place concrete structure project, the formwork project generally accounts for 20% ~ 30% of the cost of the concrete structure project, accounts for 30% ~ 40% of the project workload, accounts for about 50% of the construction period. FORMWORK technology directly affects the quality, cost and benefit of construction, so it is an important content to promote the progress of construction technology in China.

With the development of the real estate industry and the construction of various projects, the template industry has been developed rapidly. In 2009,585 million square meters of building formwork were used, an increase of 7.3 percent year-on-year. Industry insiders expect that in 2010, with the support of favorable policies and the gradual improvement of the international economic environment, the production scale of China's construction formwork industry will maintain a growth rate of about 10% ; From 2011 to 2012, the annual growth rate of China's construction formwork industry will be about 15% , and by the end of 2012, the output of China's construction formwork industry will reach about 220 million square meters.

According to statistics, China's steel formwork market in 2009 was 153 million square meters, a year-on-year growth rate of 6.9 percent. The output of steel formwork, including steel composite panels and all-steel large formwork, was 39.7 million square meters, with a 6.6 percent year-on-year growth rate. The new steel modules produced each year are equivalent to about 3 million tons in weight, equivalent to 43 French Eiffel Tower Steel consumption 70,000 tons of Eiffel Tower steel consumption, 27 Beijing Bird's nest steel consumption 110,000 tons of Beijing bird's nest steel consumption, 3.7 HANGZHOU BAY spans, 800,000 tons of steel Hangzhou Bay Bridge for the bridge

In 2009, Liuzhou's plywood market was 300m sq m, up 8.4 per cent year-on-year, while its annual output was 77.3 m sq m, up 9.7 per cent. The market size of bamboo plywood formwork was 122 million square meters, a 7.9 percent year-on-year growth rate, and its annual output was 31.4 million square meters, a 9.1 percent year-on-year increase. Every year nearly 110 million square meters of bamboo / Wood are produced for building formwork.

It is estimated that 16 million large trees with a diameter of 30 centimetres, or 10,000 hectares of forest, need to be cut down each year to produce these timber templates. The 10,000 hectares of forest can produce 2.7 million tons of oxygen per year, absorb 3.6 million tons of carbon dioxide per year, absorb 1,000 tons of sulfur dioxide per year and absorb / Block 120,000 tons of dust per year. 2 The pattern of the building template will be quietly rewritten

It is reported that since the 1980s, there have been companies in the exploration of this composite building template, but because of material technology, the problem has not been overcome, the product development has been basically put on hold. With the High Polymer Composite Material Synthesis Technology as the National 863 Major Science and Technology project achievements, after a number of key universities and research institutes in China's professional technology, technical personnel for many years of research and development and mature and perfect, the development of the composite template was able to continue.

In the early 1970s, the main building structure in China was brick-concrete structure, and the formwork used in building construction was wood formwork. In the early 1980s, a variety of new structural systems emerged, cast-in-place concrete structure Mengzeng. Due to the scarcity of wood resources in our country, under the policy of "replacing wood with steel" , our country has developed advanced construction technology of combined steel formwork, reformed construction technology of formwork, and saved a lot of wood, more than 75% of steel formwork has been used, more than 1,000 steel formwork factories have been set up, more than 13,000 steel formwork leasing enterprises have been set up, and about 15 million cubic meters of substitute timber have been saved each year, with significant economic and social results achieved. Since the 1990s, China's building structure system has made great progress, with large-scale construction of high-rise buildings, super-high-rise buildings and large-scale public buildings, and large-scale infrastructure construction, with the rapid development of urban traffic, expressway and railway, new requirements for formwork and scaffold construction technology are put forward. Our country continuously introduces foreign advanced mould base system, at the same time also has developed many kinds of new mould base and scaffold. At present, the pattern of composite steel formwork in our country has been broken, and it has been gradually changed into the pattern of multiple templates.

Industry insiders predict that the appearance of composite building formwork will certainly break the situation of steel formwork, wood plywood formwork and bamboo plywood formwork, which have been gradually formed in China's building formwork industry, will create a new green building template industry, open a new realm of construction in China, to achieve the Chinese dream of green, energy-efficient construction.

Wooden building template is a kind of artificial board. After the use of glue-coated Veneer according to the direction of wood grain staggered slab, in the heating or non-heating conditions from pressing. The number of layers is usually odd, and a few have even numbers. The physical and mechanical properties of Longitudinal and transverse directions have little difference. Commonly used are plywood, plywood and so on. Plywood terms definition Plywood-Classification GB 9846.1-88 this standard refers to the use of the international standard ISO2047-1972 plywood vocabulary.

When the concrete of the bottom or top slab is finished and has a certain strength ≥1.2 MPA, that is to say, no soft and no trace can be pressed by hand, then the person can start to cast the axis. According to the axis position, the dimension line of wall column section and the Control Line of formwork 500 are put out to facilitate the installation and correction of beam formwork. After the concrete is poured and the formwork is removed, the floor 500mm elevation control line is introduced and the control line at the bottom of the floor is directly introduced to the upper part of the floor. Firstly, the control line of the main axis of the building is quoted and measured according to the measuring hole of the floor axis, and each axis is drawn from the control line as the starting point. According to the axis and the construction drawing, the inner line, the side line and the outer control line of the template are popped out with the ink line, the first three lines of construction must be in place to facilitate template installation and calibration.