FAQ – Precast concrete
Questions and answers around the precast concrete technology, production and building system
Listed below, you may find typical questions of our customers from all over the world about planning and introduction of precast concrete building systems.
If you have a question that we haven't answered here, feel free to contact us. Our precast concrete experts are gladly at your disposal and provide help and advice.
Preconditions for industrialized construction with precast concrete elements
In order to start production of precast concrete elements successfully, the following preconditions are absolutely necessary:
- The company has already a business model (i.e. real estate development).
- The management or the owner of the company is certain to produce buildings industrially.
- The company is prepared to change or adapt their planning and construction processes appropriately for the use of precast concrete elements.
Is it necessary to have experience in construction in order to start production of precast concrete elements?
It is not necessary, to the contrary. As a new entrant you are free from any habits originating in the use of traditional construction methods with bricks and/or in-situ concrete. These beginners gain knowledge about the precast concrete system faster and easier.
When using precast concrete elements the best business model is to combine the entire process from the planning to the sales of buildings in one company. This is the case for real estate developers. In order to take full advantage of the precast concrete building system the entire process should be executed by one company. If you sell precast concrete elements to third parties (construction companies), you always depend on their preferences and demand.
This is the ideal basis for building with precast concrete elements. Real estate developers are able to manage big projects. Precast concrete elements enable for a shorter construction period and faster return of money. Therefore you are able to produce more buildings with the same amount of money. Traditional construction with in-situ concrete takes four to five times longer than compared to construction with precast concrete elements. This leads to an asset turnover that is three times faster than in traditional construction.
Is it true that you have a lot of restrictions regarding appearance and architecture of the buildings?
This had been the case in the past until the mid-1990s. With the development of flexible formwork systems and automatic machines, which put the formwork into place, the production of an infinite number of different elements and buildings is possible.
Regarding the technical design, you need to consider the following:
- Products and amounts
- Level of automation
- Time schedules
It is possible to use precast concrete elements in every climate zone from -50°C to +50°C.
„Green building“ and precast concrete elements:
- Every new energy saving-technology may be implemented in precast concrete elements very easily
- Sustainability- concrete is a natural material and 100% recyclable
- Efficiency for the use of energy, water and construction material
- Minimum waste in production
- After the demolition of a building it is possible to recycle and re-use the concrete and the reinforcement for the construction of a new building
- Very good thermal performance- reduction of costs for heating or cooling with air conditioners
It is quite simple to build intelligent buildings with precast concrete elements. Due to the reason that all buildings built in precast concrete must be planned totally (means to 100%) before the production can start, imbedding of intelligent systems is very simple.
In Europe and Russia, there are production plants in use since more than 30 years.
In general, industrial plants will be depreciated over ten years. Therefore, the depreciation period should match the useful life. A detailed profitability analysis should be carried out if the utilization period is shorter.
Naturally, there are some limitations, mainly due to structural requirements.
The advantages outweigh these limitations:
- Increase in the living area due to narrow wall elements
- High quality of precast concrete elements leads to cost savings because plastering; filling of joints and painting or wall papers are sufficient
- Precast concrete elements enable for the creation of diverse and permanent façades with widely differing surface structures and colors
Naturally, there are some limitations, mainly due to structural requirements.
The advantages outweigh these limitations:
- Prefabrication guarantees for a precise production
- Load bearing walls substitute frame and skeleton structures; this leads to cost reductions
- High degree of prefabrication (fixtures like wiring, water pipes, sewage pipes etc.) reduces the installation time and the completion of buildings
- Earthquake-resistant building system
The technique is comparable to constructions with in-situ concrete and for engineers easy to understand and easy to use.
No, workers are able to assemble precast concrete elements after a training period of two weeks.
Some advantages as follows:
- Short assembly time of the building on site; therefore brief noise pollution for adjacent neighbors
- Precast elements may be stored and delivered according to workflows on site
- No scaffolding necessary, temporary bracing of precast concrete elements
Every type of building can be built:
- Family houses
- Apartment houses
- High-rise buildings
- Affordable housing
- Administrative buildings
- Industrial buildings
The precast concrete building system
You need to have a product that may be produced and sold.
Thereafter, it is important to conduct a market analysis in order to detect the market size for this product. If this analysis has been carried out successfully, it is possible to find out if setting up a production operation would be profitable based on a feasibility study.
The most important preconditions are:
- There is a market demand for precast concrete elements or you may use precast concrete elements in your own housing projects
- The company structure needs to be prepared for the use of precast concrete elements (planning and processing of projects)
- The building system needs to be adapted to the buildings to be constructed and needs to be approved by authorities
Prilhofer Consulting is able to support you in every aspect regarding the implementation of the precast concrete technology.
The first step can be a two days’ workshop at our premises or at your company to learn more about the technology and discuss the basis for your specific project.
Reasons for different building systems are different requirements concerning the market and structural needs.
Basically two systems are in use:
Precast concrete systems and half- precast concrete systems (will be completed on site with in- situ concrete).
In order to decide for a suitable building system you should use independent consulting services.
Prilhofer Consulting is able to support you with extensive know-how from more than 20 years worldwide experience, in every climate zone from -50 to +50°C. Among our clients are some of the best companies worldwide.
Which steps are necessary in order to implement the precast concrete system successfully and sustainably?
You, as a user of this technology, should keep in mind and investigate the following items:
- Which market and volumes are available?
- For which target group are these houses intended?
- Which housing types are in demand in the respective market?
- Is concrete used as construction material?
The size of the stockyard depends on many factors.
Some of the most important factors are:
- Average length of stay of products in the stockyard
- Type of transport system
- Type of stockyard management (i.e. crane, lift truck)
- Where and how will transport units be generated?
Which other investments, apart from the production plant, are necessary in order to have an entire plant for the production of precast concrete elements?
For the production of precast concrete elements, you need to have the following, among others:
- Suitable production buildings
- Office and administrative buildings
- Staff rooms
- Parking lots and roads on the property
- Stockyards (active and passive) for finished products and raw materials
- Auxiliary plants (i.e. maintenance, workshops, etc.)
There is as yet no producer of precast concrete elements in my region (country). However, is it advisable to enter the market?
You should always check the market for the acceptance of concrete or precast. Prilhofer Consulting is able to support you in establishing a test production requiring minimal investment in order to test the market.
What are the construction costs when building with precast concrete elements compared to traditional construction methods with bricks and in-situ concrete? What can I save?
With the use of precast concrete elements the construction costs are infinitesimally higher. However, construction time is only one third compared to traditional construction methods which compensates these costs several times.
You may achieve the following benefits with the use of precast concrete elements:
- Fixed final price and fixed completion date for buildings
- Short construction time- lower costs for financing and building site facilities
- Industrialized construction process - less control, fewer specialized companies and therefore less coordination necessary
- Exact calculation of reinforcement amounts in prefabrication, therefore the amount of steel is reduced
- Less risk of material theft on site
- Optimized use of material through precise input of material (cement, construction steel etc.) -Prefabrication in the production plant - Controlling
- No maintenance for the buildings
The use of precast concrete has a long tradition in Europe and also in Russia. Since more than 50 years precast concrete is used in the construction industry. The products are well accepted and contractors as well as real estate developers know how to use them.
In the rest of the world the traditional way to build is very common. Especially architects are against precast concrete because they have a lack of knowledge in this field. The best way to solve this problem is to get the whole process under one roof, starting from the design of the buildings to selling the finished apartments. This is the best way to be successful.
Industrialized construction with precast concrete elements means producing big amounts of buildings in the shortest time possible with constantly high quality and cost efficiently.
- High quality due to production independent of weather conditions
- Highest precision and quality of precast concrete elements
- Very good quality due to quality control during production
- Very good fire protection without any additional measures
- High noise protection and very good thermal performance
- Low moisture content in the finished building
This is a question that is asked very often. The answer to this question is not so easy.
The amount of investment depends on the following factors:
- Size of the plant and types of the products
- Output of the production plant
- Level of automation of the plant
In general, investment in machines and plants amounts to at most 50% of the entire investment.
Which aspect is more important to start with precast concrete production- the production plant or the product?
It is definitely the product. Once you know what you will produce and which amounts, respectively how the buildings look like and how many of them you would like to build, you can think about the production plant.
Why are there so few success stories in the field of industrial production of precast concrete elements?
Clients, who chose precast concrete production and industrial construction, may only be successful if they have dealt with the following issues in advance:
- Architecture of the houses
- Building system
- Element joints
- Organization structure in the plant
- Logistics of the plant, stockyard, construction site
The automation of production is only advantageous if it improves the following issues:
- Production efficiency (reduction of labor costs)
- Product quality (i.e. prevention of errors)
Therefore, it is important to research the following points:
- Labor costs
- Products that shall be produced
- Is it possible to produce these products automatically?
- Is the output of the plant sufficient in order to produce automatically?
The safest way to an efficient production plant is to carry out a study, independent of machine suppliers.
Where do I get independent consulting and support for the development of a precast concrete production?
Independent consulting should be ordered from companies that are specialized in consulting and planning only. These companies have an extensive know-how in this field. Companies that sell other products and offer additional "free of charge consulting services" have a conflict of interest regarding independent consulting services. These services are offered free of charge because the companies hope to sell their core products.
How important is independent consulting for the implementation and the development of a precast concrete production?
An independent consulting is important due to several reasons:
- An independent consultant is a partner who supports you during the whole project process. You may discuss with him every technical and economical question in an open and neutral way.
- To get the best price-performance ratio for machines and plants different suppliers should make an offer, if possible.
- To make offers of different suppliers comparable and assessable. This is important for the objective assignment of the machine technology.
Suppliers of machines and plants offer free of charge consulting services for the development of production plants. Is this consulting sufficient in order to start?
This kind of consulting is offered by suppliers because they hope to be able to explain and finally sell their own products and solutions. These companies have experience with their own machines and solutions. This kind of consulting is adequate if the customer wants to buy just a single machine.
Concerning the planning of an entire production plant or factory, the customer also needs consulting in the following areas:
- Production building
- Stockyard logistics
- Plant logistics
- Construction site logistics
- Establishment of a technical department
- Production processes
- Element joints
- Building system
- CAD system
How important is the development of a layout for the precast concrete production plant regarding the plant output?
The layout of a plant is like the architecture of a building. If the rooms are too small and the stairs and the kitchen are in the wrong place, it is very difficult to change that afterwards. The machines and plants are like the furniture. Only a sophisticated layout guarantees for an excellent material flow and efficient production.
The efficiency of the factory needs to be calculated for the entire process. This means from the delivery of material to the shipment of the finished products. An efficient production without a suitable plant infrastructure will only lead to a partial success. In order to be fully successful, it is important to plan the entire factory as detailed as the production plant.
The entire process will be controlled and created transparently if an independent consultant and planner coordinates and plans it.
One of the first steps in this process is the feasibility study. This study includes among others the investment costs for the entire project not only for machines and plants. An overall planning allows for the consideration of all necessary areas within the factory and the calculation of their costs.
The only possibility is the preparation of a detailed request for proposal. It has to contain all relevant technical and economic data, like scope of delivery, assembly and inspections, as well as all technical and qualitative requirements of the product. Thus, all important pieces of information for the project are gathered in one document.
What are typical steps in the planning and tendering process regarding the purchase of a precast concrete production plant?
- Feasibility study
- Tender for the equipment
- Negotiations with suppliers
- Awarding of all contracts to suppliers
- Detailed planning of the plant
- Construction of the plant
- Test operation
- Start- up
How do I avoid making mistakes regarding the planning of a production plant for precast concrete elements?
Obviously, the term "mistake" is relative. An important factor of the planning is that the parameters investment costs, production output, quality and efficiency of production are compatible. This has to take place before the actual planning (layout planning) is carried out and is done best in form of a feasibility study.
Assuming that a production plant is a plant in which every important machine is installed only once, the following is true. A production of up to ten pallets per hour of simple products (floor slab) is possible, depending on pallet size. This is equivalent to an output of approximately
200 to 250 m² per hour. Regarding more complicated products, it is not possible to make any specifications without detailed planning as product details must be known (element sizes and complexity factor).
Planning & set-up of a precast concrete production
Independent consultants and planners may offer you planning reliability (Plant output, costs, as well as time periods for construction and start-up). References of finished projects are the best evidence for that.
At best, especially concerning financing, you can expect the following time periods:
- 0-2 months: Initial meeting and feasibility study
- 2-3 months: Tender phase
- 8-12 months: Construction of the precast concrete plant
- 1 month: Start-up
A feasibility study provides you with certainty regarding the scope of the entire project (i.e. return on investment). The feasibility study gives you an overview of costs, timelines and profitability of the project. The feasibility study serves as a basis for investment applications or negotiations with banks, authorities, etc.
Is the machine technology of different suppliers of equipment for precast concrete plants comparable?
Different suppliers have partially differentiating concepts in sections, like concrete spreaders, construction of robots and reinforcement production.
Obviously, suppliers are comparable with regard to the entire production plant and the products produced with this plant if you have sufficient expertise. Prilhofer Consulting is able to make different concepts and offers comparable for clients regarding technical and economic data.
If you plan to build a new production plant and you would like to see production plants installed by potential suppliers as references, you should be vigilant about the following:
- Does the plant produce the same product that you would like to produce?
- Who was responsible for the design of the plant (producer, machine supplier or planner)? It's recommended to ask the producer.
- You should stay at least one hour in the plant in order to check if the output corresponds to the information given before the visit.
- Talking to the producer about his experiences regarding the plant is highly recommended.
If you would like to use automatic machines and plants in the production plant it is absolutely necessary to use a CAD system. The decision about the CAD system and its corresponding interfaces to the master computer and the control system should be taken at least when ordering the plant. Automatic machines and plants may only be operated with CAD data.
How important is the master computer and the control system for the production of precast concrete elements?
If you would like to use automatic machines and plants in the production plant it is absolutely necessary to use a CAD system. An automatic plant without a suitable control system and master computer will always have problems controlling the machines and maintaining efficiency of production if you produce individual elements.
This question is not easily answered. Machine suppliers have different approaches regarding the construction of machines and plants. There are companies that are specialized in highly automated equipment, whereas other companies rely on simple sturdy machines. In order to decide for the most suitable machines for the required application, you should use the consulting services of an independent planner.
This depends on the product that will be produced in the production plant. For simple products (like half precast elements) the batching plant doesn't need any special requirements.
Production plants which are producing products that need different types of concrete must have a customized batching plant.
In general, the batching plant should be operated automatically. It is very important that the batching plant and the supply of concrete are considered quite early during the overall planning process.
This depends on the product. An efficient automated reinforcement fabrication is very important for products with high reinforcement content in order to produce competitively.
For production with stationary forms and low output, manual solutions with standardized meshes and rod steel are normally sufficient.
The reinforcement production needs to have an optimal material flow to the production plant in order to guarantee for smooth production operations. Moreover, it is very important to consider the reinforcement area very early during the overall planning process.