by Click the blue word / pay attention to the cost analysis of our precast buildings and cast-in-situ buildings Author: Wang Qicun preface the total output value of the construction industry in 2016 reached 19.36 trillion yuan, accounting for about 26% of the total GDP, with more than 51.85 million practitioners.
It is a pillar industry worthy of the name.
Precast building is a new construction technology vigorously promoted by the state.
The development of precast building plays an important role in the construction market in the future.
The change cost of precast buildings and cast-in-situ buildings will increase, and many regions of the country will give financial incentives and many preferential policies.
It is an important task to analyze the cost management of enterprises in the future.
It is very important for construction enterprises to adapt to market changes.
Only by adapting to the market can they bring good benefits.
This paper analyzes the cost factors through the comparison method between precast concrete buildings and cast-in-situ concrete buildings, first from the perspective of investment and operation, then from the perspective of construction management (manufacturing, transportation and installation process), and then from the comparative analysis of labor, material and machinery consumption of prefabrication and cast-in-situ within the building quota.
After class, the topic of discussion was suggested, the projects suitable for precast buildings were discussed, and the development history of precast concrete buildings was comprehensively analyzed based on previous historical experience.
The value of part01 capital cost.
If the precast concrete building needs to be invested in the early stage of construction, it shall be handed over to the formal construction drawings of the precast component manufacturer for construction before commencement.
For cast-in-situ concrete construction, general enterprises purchase the main materials and enter the site 5 days before the application period, and the labor cost is paid with quarterly or annual holidays.
Compared with precast concrete, cast-in-situ materials and labor funds take a lot of time after investment.
[case] it is estimated that the single building 18F is used as a reference, each household is 120m2, one ladder and two households are counted, and the building area is 4320m2.
The concrete content of the main frame structure is 0.39m3/m2 and the reinforcement content is 0.048t/m2.
The construction period is estimated as 7 months.
The specific proportion is detailed in the following table: the amount of investment obtained from the above table is 1.5 million yuan.
When Party A pays, it takes 4 months to construct to the 12th floor.
Calculated according to the market loan interest rate of 1.5 cents per month, 150 * (1.5% * 4) = 90000 yuan, equivalent to a building area of 21 yuan / m2.
The amount of advance payment is calculated as follows: picture source: compilation of project cost Q & a capital cost is very important for construction enterprises.
A lot of money is invested in the early stage to calculate loan interest.
Especially for small and medium-sized construction enterprises, cash shortage is normal in the operation process.
The general operation mode is to fill the flow funds through image progress payment or monthly progress payment.
The internal management of small and medium-sized construction enterprises is also more complex.
It is often to advance the funds of built projects to new projects to maintain daily operation through fund allocation.
The precast concrete building can be filled by the construction party (Party A) in advance of the project payment.
The construction enterprise has insufficient funds, but the small-scale real estate operation is still difficult.
It is often operated by means of rapid realization of funds through market financing channels or pre-sale.
In the whole project operation cycle, the construction party’s funds are also a gap in the construction stage.
The time of land purchase, planning and design and bidding accounts for more than one year of the whole project operation.
It will take another year for the house to be pre sold until the main structure is completed.
It is also in the stage of “green and yellow” that advance payment is made first, which also increases the cost.
Prefabrication manufacturers have invested a lot of money in the construction stage, and it is impossible to advance money in the operation stage.
Generally, advance payment is required for the transaction of customized components.
According to the previous transaction method of similar goods, the advance payment is 5%, and 95% is paid at the time of delivery.
If the steel structure project needs to advance 25% ~ 30%, the components will be made.
The current situation is that prefabrication manufacturers produce in batches for a project and a high-rise building is completed in two or three batches.
Such a production process requires a lot of funds to purchase raw materials.
Whether it is the construction enterprise, the construction party or the manufacturer, there is a gap in capital.
Whoever invests has to increase the cost.
Through the calculation of 60% prefabrication of an 18 storey residential building, this paper obtains the increased cost of 21 yuan per building square meter.
Although it is the data calculated theoretically, it is reasonable and the actual situation.
Part02 cost analysis in the process of construction management the construction of new construction technology requires comprehensive consideration of technology and risks for construction enterprises.
Manpower allocation, interleaving and coordination are a new concept, which poses a great challenge to the construction organization ability of construction enterprises.
In the process of construction management, the transportation links of components, site stacking conditions, site requirements, selection of vertical transportation machinery, construction period, drawing changes and transaction tax burden should be considered comprehensively.
When the labor cost accounts for 30% of the total cost price, the new process will increase the labor cost by more than 10%.
When the PC component rate is 60%, the cost can be increased by 5 yuan / m2.
The transportation of components is very important, especially on the important traffic trunk roads in the city.
The volume size of components and the traffic congestion period should be considered.
The body of commercial concrete mixer truck is short and the size of small truck is the same, while the prefabrication of precast components must increase the space and body length to ensure no loss of components.
If the transportation of oversized vehicles is limited to night, the on-site storage conditions shall be limited, and the hardened area of the on-site stacking area shall be up to, and the limit of vehicle turning site and component stacking site shall be much higher than that during cast-in-situ pumping.
The prefabrication plant must be located in remote areas with low land cost and close to the sand and stone mining area, which may increase the transportation distance, and increase the high-speed charge and automobile fuel consumption, which will also increase the cost.
[case] it is estimated that the over haul distance from the precast component factory to the construction site is 65km..
