20 August 2019

Table of Contents for Precast Concrete & Equipment





Precast Concrete & Equipment

Revolutionising construction

 

Most of the developing nations are today facing a massive crisis situation— housing. Though most of them have got acquainted and found out solutions to deal with the problem, there is always a need to find alternative measures to face this growing problem. This is where Precast concrete acts as a promising solution feels ROHAN AMBIKE.

 

 

Fast Facts
  • The precast concrete market was valued at US$ 99.13 in 2016 and is projected to reach US$ 138.96 billion by 2022.
  • The urban housing accounts for about 85-90 percent of the total investments and affordable housing requirement is about 70 percent of total investments.
  • Precast concrete construction will save valuable time and helps to reduce the risk of project delay and possible monetary losses.
  • The Indian construction industry is presently estimated to be worth around $740 billion.

 

 

 

The precast concrete manufacturing industry primarily today produces two basic types of concrete products – precast and prestressed concrete. As per industry analysts, the concepts though closely associated are often misunderstood among customers and are thought to be the same. While precast concrete is produced by casting wet concrete in a reusable mold of a specific shape, prestressed concrete is compressed between steel bars for additional strength and durability. The end product achieved – slabs, panels, roof tiles and beams – are today most commonly used across the world in the construction of commercial buildings, bridges, residential structures, highways, even parking lots etc.

 

 

 

While precast concrete is a widely accepted technology in the developed markets, it is yet to establish its stronghold in India. According to industry experts, apart from certain countries in the Asia-Pacific region, most economies have already adopted the precast concrete way of construction. The technology is today used in about 80 per cent of the building construction process in countries like Bahrain and Dubai. According to industry experts the Indian construction industry is worth about $500 million and only 2 per cent of its share is occupied by precast technology as against conventional methods.

 

 

 

However, a gradual shift is expected to evolve with increasing focus on infrastructure activities at cost competent rates. In India the technology has gradually gained in momentum in the infrastructure industry. Today many tunnels, bridges and even roads are constructed using precast technology. The technology is expected to further gain popularity with rapid expansion of activity in the realty segments.

 

 

 

Advantages of precast concrete

 

Some of the advantages of using precast concrete construction are as follows:

 

 

Structurally Secure and Efficient

 

Precast concrete is specifically designed and constructed to have a significantly high span-to-depth ratio that allows it to bear loads better, reducing the need for additional columns and supports within the internal structure of the building. Its lighter weight can also reduce the size of needed structural material and overall foundational depth. Precast concrete strength isn’t sacrificed by its lightweight construction, though, which means it’ll stay secure and even be put under reduced dead loads when properly installed. All of that weight savings paired with high strength means buildings can use precast concrete to reach heights of up to 80 stories.

 

 

 

Precast concrete strength isn’t sacrificed by its lightweight construction, though, which means it’ll stay secure and even be put under reduced dead loads when properly installed. All of that weight savings paired with high strength means buildings can use precast concrete to reach heights of up to 80 stories.

 

 

 

Various reports say that, compared to traditional concrete building construction, precast concrete can reduce floor depths by up to four inches. So, this savings on a 60-story building will reduce the overall height by an average of two stories’ worth, or 20 feet.

 

 

 

Thermal Friendly

 

Large-scale infrastructure requirements create unique weather and element demands, including the ability to keep heat in during the cold months and keep heat out in the summer. When you’re not using the right materials, you’re looking at a significantly increased cost all year long.

 

 

 

Precast concrete advantages for the building owners are big, but many believe it’s thermal efficiency that’s among the most cost advantageous. Precast concrete is denser and less of a thermal conductor, so it doesn’t move heat around your building. That means you’ll reduce peak heating and cooling loads — this type of concrete is slow to react and easier to heat or cool relative to external and temperatures.

 

 

Fire Tough

Precast concrete is fireproof when properly constructed and combined with the right insulation and paneling on walls and ceilings — it can limit a fire’s ability to spread between rooms. Precast concrete itself also doesn’t catch fire, won’t burn and typically does not drip or melt unless there is a special additive layered on top or introduced into its construction.

 

 

 

Using precast concrete for all of the walls in a stairwell means the people inside will be protected, and the construction of your building can limit any harm or loss of life in the event of a future emergency. However if there is a fire, the precast concrete strength and uniformity prevent it from major damage. In most cases, the building owner will need to replace paneling but not the concrete underneath.

 

 

 

Noise Reduction

 

Precast concrete is incredibly dense, and the process used to create it makes it denser and more resilient than other concrete options. This density is why it is used in many walls and privacy construction elements for large-scale construction as well as sound walls around communities that may face a highway. Precast concrete’s density effectively reduces sound and creates a privacy zone when it is used as a barrier in large-scale construction projects. This makes it a perfect option for both residential and commercial jobs.

 

 

 

The ability to deflect or absorb sound also makes precast concrete a smart acoustic material. For example, bounce away the road noise outside, while reflecting internal noise back toward the project’s center so your customers enjoy things like conversation and music inside their homes.

 

 

 

Reduced Construction Time and Cost

 

Precast concrete construction will save valuable time and helps to reduce the risk of project delay and possible monetary losses. Precast design and production of elements can be started while the construction site is under survey or earthworks. Production is also unaffected by weather conditions due to the controlled environment of the casting area. Also, the usage of large precast panels will reduce the time taken to complete the structural works. Therefore, other trades such as painting and electrical wiring can begin work sooner.

 

 

 

High quality and aesthetical value of products

 

Precast products are manufactured in a casting area where critical factors including temperature, mix design and stripping time can be closely checked and controlled; and this will ensure that the quality of precast products are better than cast-in-situ concrete. A huge sum of money will be saved by not having to do rectification works. Also due to factory-controlled prefabrication environment, many combinations of colours and textures can be applied easily to the architectural or structural pieces. A vast range of sizes and shapes of precast components can be produced, providing a great deal of flexibility and offer fresher looks to the structures.

 

 

 

Cleaner and safer construction sites

 

Usage of precast elements eliminates or greatly reduces conventional formworks and props. Precast construction also lessens the problem of site wastages and the related environmental problems. The prefabricated products also provide a safe working platform for workers to work on. Workers and materials are also greatly reduced at the construction sites. Using Just-in-Time principles, the precast elements are kept at the factory yard until the site is ready for installation. Also, as elements are produced in the plant and mostly designed to be repetitive, minimal wastage will be experienced at both factory and construction sites.

 

 

 

Lower total construction costs

 

All of the above simplify the construction processes and increase productivity, quality and safety. As a result, the total costs of construction are reduced. More often than not, most of the opponents of precast construction only use the costs of materials in comparing the in-situ and precast construction without realising that there are hidden costs to the traditional methods. Also a contributing factor to the low usage is the fact that Malaysia has always been able to source cheap labours from neighbouring countries. Therefore, the industry players are very reluctant to change to the new construction methods. As a result, the country is faced by problems of low quality, productivity and safety in the construction industry due to high dependency of manual labour. The country also suffers from the outflow of monies as well as social problems. If the labour supply experience sudden reduction while demand remains the same, labour costs will definitely be increased and produce more problems to the industry.

 

 

 

Increased Quality of Structural Elements

 

Precast concrete elements produced in plants using modern techniques and machineries. Raw materials such as concrete, sand, and reinforcement bars are under high level of quality control. Formworks used are of higher quality than those used at construction sites. This allows truer shapes and better finishes in precast components. Precast components have higher density and better crack control, offering better protection from harsh weathers and sound insulation. High density is achieved by using vibrating table or external vibrators placed on formworks. Precast concrete also provide better fire resistance for reinforcement bars. When compared to in situ concrete, this reduces the amount of long-term movement, which needs to be recognized in building design.