New construction area of precast buildings in China from 2013 to 2019 (10000 ㎡) in 2019, the top 10 precast building area of China’s real estate enterprises, but we can’t blindly pursue high assembly rate at this stage, because China’s precast buildings are still in the primary stage, and both technical level, management mode and specifications and standards are continuously explored and improved.

The construction quality of key nodes shall be mainly controlled for cast projects..

High cost.

Cost analysis of aluminum mold, steel mold and wood mold in addition to the cost of precast components and molds, the transportation cost is also key.

Comparative analysis on the cost of cast-in-situ components and precast components precast building components have low degree of standardization, weak universality of molds, and the turnover times of molds can not reach the life design, so the service life is short, and the loss of molds also indirectly increases its cost.

Several opinions on further strengthening urban planning and construction management put forward that by 2025, the proportion of precast buildings in new buildings will reach 30%.

The standard layer construction period of a real estate company’s cast project shows that the higher the assembly rate, the longer the construction period.

Long construction period from the comparative analysis of the construction period of traditional construction and precast construction, it can be seen that the overall construction period of precast project is higher than that of traditional cast-in-place project because the construction period of each link of design, production and construction is longer than that of traditional project.

Due to different economic levels, the development imbalance is obvious and the gap is very large.

The immaturity of the precast construction market has led to the loss of many component manufacturers, and private enterprises dare not easily enter the field of precast construction.

The cost of precast construction is about 15% – 30% higher than that of ordinary cast-in-place construction.

At present, the development of precast buildings is mainly dominated by Beijing Tianjin Hebei, Yangtze River Delta, Pearl River Delta Urban Agglomeration and some provincial capitals with better economic development.

The cost gap of precast components can be seen from the figure below.

1.

According to the consumption quota of precast building projects issued by the Ministry of housing and urban rural development, the construction cost of small high-rise residential buildings with precast concrete structure is 2152 yuan / m2, that of high-rise residential buildings is 2416 yuan / m2, with an average construction cost of 2284 yuan / m2, that of high-rise residential buildings with precast steel structure is 2776 yuan / m2, and that of traditional cast-in-situ concrete structure is 2000 yuan / m2.

Lack of experience in assembly projects and few professional companies with assembly design, production and construction capacity.

The vertical components are transported vertically, about 7-8m per vehicle ³ Concrete members and flat members can be transported with full load.

This series of factors lead to high cost, long construction period, uneven quality and high safety risk of cast projects.

In 2019, Sichuan Province The newly started precast building area in Hunan Province (10000 m2) China’s precast buildings are in a new stage (primary stage), the main factors restricting the development of precast buildings are: immature technology, imperfect upstream and downstream industrial chain, imperfect norms and standards, high cost, great difficulty in integrated management of design and construction, etc.

The following is an in-depth analysis of these industry pain points.

Through market research, the author analyzes the transportation cost of precast components: if the 3M * 17.5m component transportation vehicle is fully loaded with 30t (including the total weight of vehicle, precast components and steel frame), the charge is 3700 yuan within 250km.

It can be concluded that the transportation cost of each precast concrete component is about 400-500 yuan / m ³。 2.

Flat End Socket Cross Pin

The traditional cast-in-place mode is still used for architectural scheme design, and then the component splitting design leads to many types of components, complex modeling, and difficult production, transportation and installation.

For precast building, the reliability of connection mode and the quality of key connection nodes directly determine the quality of precast building.

through field investigation and analysis, the author finds that there are three main reasons for the imperfect industrial chain.

The development speed of precast buildings is slow in the third and fourth tier cities affected by the economic level.

Comparative analysis on the construction period of standard floor of traditional construction and precast construction of a high-rise residential project the reasons for the long construction period of precast project caused by the construction period of standard floor of precast project of a real estate company are mainly reflected in the links of design, production and construction, the degree of influence, relevant cause analysis and solution suggestions, as shown in the figure.

This paper makes a multi-directional interpretation around the pain points and development trend of precast buildings, and analyzes the characteristics, difficulties and significance of developing precast buildings for industry reference, so as to improve the level of precast buildings.

In 2019, the total area of precast buildings of China’s top 10 real estate enterprises reached 87.34 million m2, and the newly started precast buildings in China reached 418 million M ²， The proportion of new construction area in China is about 13.4%, an increase of 45% over 2018.

The cost of cast project is higher than that of traditional cast-in-place project, and its cost increment is reflected in material cost and labor cost.

Comparative analysis of the cost of various types of precast buildings and cast-in-situ concrete the main reasons for the high cost of precast projects are: the high material cost of precast concrete components, high mold cost, large mold waste, low recycling rate, large volume of precast components and self weight, resulting in high transportation cost.

Precast buildings Division At the start-up stage, the upstream, middle and downstream industrial chain is not perfect.

Reason analysis of long construction period of precast project 3 quality is mixed.

Cost / construction period / quality / safety four pain points analysis the development of precast buildings needs the support of economic level.

The construction unit and design unit pay too much attention to the facade and house type design, and do not consider the characteristics of precast buildings in advance.

We should fully understand the characteristics and difficulties in the application process of precast buildings, and constantly sum up experience from the project Explore a new construction road in line with the development of enterprises, industries and national conditions.

The main reasons for the low degree of standardization are: the design unit lacks the concept of standardization and modularization, and does not understand the production and installation process of precast components.