by Word count 4300, reading time 8 minutes, searching for the source, targeted—— The 8th China (International) Prefabricated Concrete Technology Forum was held in Shanghai from May 18th to 19th.
On the afternoon of the 19th, I visited Shanghai Construction Engineering Group Industrialization Base No.
2 on site.
Taking this opportunity, we will learn about the two mainstream production processes of prefabricated components on site, identify the reasons for high production costs, and explore ways to reduce incremental costs.
Previously, we shared that the significant price difference between prefabricated components and traditional cast-in-place components is the main reason for the incremental cost of prefabricated structures.
As shown in the figure below, in the incremental cost of a prefabricated project in Shanghai in 2017, the price difference of components accounted for 73%.
(Note: the object of the whole discussion is PC prefabricated structure, not the whole prefabricated building) The main reason is that the weighted comprehensive unit price of various types of reinforced concrete components is (including reinforcement, concrete, formwork; the comprehensive unit price of the full cost of supply and installation): (1) Traditional cast-in-place components: 1474 yuan/m3 (100%); (2) Prefabricated components: 4000 yuan/m3 (271%).
(Special note: The chart data is based on the 2017 bidding price of a certain component factory in Zhejiang Province, not the one visited this time.) Further analysis of the supply price of PC components shows that in the supply price of prefabricated components, excluding fees and taxes, labor costs and mold costs account for the highest proportion, accounting for a total of 32%, exceeding the proportion of main materials (steel bars and concrete account for 25%): (1) labor costs: 600 yuan/m3, accounting for 17%, ranking first; (2) Mold fee: 479 yuan/m3, accounting for 15%, ranking second.
Therefore, to reduce the price of prefabricated components, the first to bear the brunt are labor costs and mold costs.
Next, let’s delve deeper into the component production line and explore the truth.
（1） The following figure shows the semi-automatic assembly line for the production of prefabricated laminated floor slabs in the Building Component Industrialization Base (Base 2) of Shanghai Construction Engineering Group The cost of mold for producing prefabricated truss composite panels is very low.
Because the molds for automatic or semi-automatic assembly lines are not customized, but complete sets of equipment.
Even if the laminated board is produced with a fixed bench mold, the bottom mold is also the surface of the bench mold, only the edge mold.
The shape of the edge mold is regular, the size is uniform, and the versatility is strong, so it can be reused multiple times.
For the time being, based on a turnover of 100 times, the mold cost for prefabricated laminated floor slabs is within 100 yuan/m3
.
