Precast Concrete

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PRECAST CONCRETE

Constrofacilitator

Knowledge and b2b portal for construction and infrastructure

eMAGAZINE August 2023 V05 eM-08

Inside What is precast reinforcement Its

F advantages and types F

Benets & challenges of precast construction

F

An overview precast concrete erection method Precast concrete for infrastructure

F projects; demand and applications Different types of precast concrete

F products and their uses

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PRECAST CONCRETE

The demand for precast concrete in India has surged significantly in recent years, primarily driven by the need for efficient and rapid construction solutions to accommodate the country's fast-paced urbanization. Precast technology allows for quicker project completion, which is essential in addressing the escalating demand for residential and commercial spaces, as well as infrastructure development. Moreover, the durability and quality of precast concrete structures make them an attractive choice, particularly in a country prone to diverse environmental challenges. Additionally, as India places increasing emphasis on sustainable building practices, precast components are being widely adopted for their eco-friendly attributes, further fueling the demand in the construction industry. In this edition of eMag we have covered topics What is precast reinforcement Its advantages and types, Benefits and Challenges of Precast Construction, An overview precast concrete erection method, Precast Concrete for Infrastructure Projects; Demand and applications and Different types of precast concrete products and their uses. August 2023 • Constrofacilitator

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What is precast reinforcement Its advantages

04 and types

08 Benefits and Challenges of Precast Construction An overview precast concrete erection

12 methods and equipments 22

Precast Concrete Elements used for Infrastructure Projects; Demand and Applications Different types of precast concrete products

26 and their uses

08 14 16 21

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Constrofacilitator • August 2023

PRECAST REINFORCEMENT

What is precast reinforcement? Its advantages and types

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recast concrete reinforcement refers to the method of reinforcing materials like steel bars or mesh into precast concrete components before they are casted. These reinforcement materials are strategically positioned within the concrete forms to enhance the structural integrity, loadbearing capacity, and durability of the precast concrete elements, such as panels, beams, columns, or other

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architectural and structural components. The use of precast concrete reinforcement helps ensure consistent quality and efficient construction processes, as the reinforcement is already in place when the concrete is poured and cured. Why precast concrete reinforcement is needed: 1. Strength and Load-Bearing Capacity: Precast concrete elements often need to support significant loads, such as the weight of buildings,

bridges, or infrastructure. Reinforcement, such as steel bars or fibers, enhances the tensile strength of the concrete, allowing it to withstand bending and tension forces. 2. Durability and Longevity: Reinforcement helps prevent cracking and structural failure by distributing stresses and loads more evenly across the concrete. This ensures the precast elements maintain their structural integrity over time, reducing the risk of premature deterioration. August 2023 • Constrofacilitator

PRECAST REINFORCEMENT

3. Crack Control: Concrete is prone to cracking due to factors like shrinkage, temperature changes, and applied loads. Proper reinforcement, such as rebar, welded wire mesh, or fibers, helps control and limit the formation of cracks, which can weaken the structure. 4. Flexibility in Design: Reinforcement materials provide designers and engineers with greater flexibility to create innovative and efficient precast structures. They can design elements with longer spans, thinner sections, and unique shapes, while still maintaining the necessary strength and stability. 5. Enhanced Performance: Different types of reinforcement offer specific benefits. For example, prestressed reinforcement can increase loadcarrying capacity, while fiber reinforcement can improve durability and impact resistance. 6. Construction Quality and Control: Precast reinforcement is implemented in a controlled manufacturing environment, ensuring consistent quality and accurate placement

of reinforcement elements. This reduces the potential for human error during on-site construction.

or cages to reinforce various structural elements. 2. Welded Wire Mesh:

7. Adaptability to Site Conditions: Precast elements with proper reinforcement can be designed to meet specific site conditions, including seismic loads, soil conditions, and environmental factors. Different types of materials used for precast concrete reinforcement, 1.Reinforcing Bars (Rebar): Reinforcing bars are steel rods typically available in various diameters and lengths. They are inserted into the precast concrete to provide tensile strength and help distribute loads. The rebars enhance structural integrity by resisting tension forces, reducing cracking, and preventing structural failure. It's versatile, easily cut to specific lengths, and can be shaped as needed. It is used in columns, beams, slabs, and foundations. Rebar can be arranged in grids

Welded wire mesh is a grid of steel wires welded at intersections, forming a mesh pattern. It's available in various wire gauges and mesh sizes. It provides uniform reinforcement distribution, controls cracking, and improves impact resistance. Its installation is relatively quick and efficient, reducing labour costs. It is used in applications like floor and wall systems, precast panels, and paving. It's especially effective in areas with minimal load-bearing requirements. 3. Prestressed Reinforcement: Prestressed reinforcement uses tensioned steel cables or bars to induce compressive forces in the concrete, increasing its load-carrying capacity. It reduces deflection, minimizes cracking, allows for longer spans and thinner sections, and enhances structural efficiency. It is used in precast concrete components like beams, girders, and bridge elements, where high load-bearing capacity and longer spans are required. 4.Reinforcing Mesh: Reinforcing mesh consists of interconnected steel bars or wires, forming a grid pattern. It provides uniform reinforcement distribution, improves crack control, enhances structural strength, and simplifies construction. It is used in wall panels, floor slabs, and other precast ele-

August 2023 • Constrofacilitator

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PRECAST REINFORCEMENT

ments to reinforce against shrinkage and temperature-related cracking.

mental and decorative precast elements such as facades, cladding, and ornate panels.

5. Expanded Metal Lath: Expanded metal lath is a sheet of expanded metal, typically made of galvanized steel, providing a mechanical key for plaster and stucco applications. It enhances adhesion of finishing materials, improves crack resistance, and provides a uniform surface finish. It is used as a reinforcement layer in exterior and interior plaster and stucco applications. 6. Glass Fiber Reinforced Concrete (GFRC): GFRC involves adding glass fibers to the concrete mix, creating a lightweight, durable material. It offers lightweight construction, allows for intricate shapes, provides high strength, resists corrosion, and enables aesthetically pleasing architectural elements. It is used for orna-

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7. Basalt Fiber Reinforced Concrete (BFRC): BFRC incorporates basalt fibers into the concrete mix to improve its mechanical properties. It offers resistance to high temperatures and fire, enhances tensile strength, provides good chemical resistance, and contributes to long-term durability. It is used for applications where fire resistance and high-temperature performance are essential, such as in industrial environments.

extends service life, and offers corrosion-resistant reinforcement. It is used to strengthen and retrofit existing structures, such as bridges, columns, and beams, as well as in new construction for increased load capacity. 9. Steel Fiber Reinforced Concrete (SFRC):

8. Carbon Fiber Reinforced Polymer (CFRP):

SFRC incorporates steel fibers into the concrete mix to enhance its mechanical properties. It improves impact and fatigue resistance, enhances toughness and ductility, reduces cracking, and increases durability. It is used for industrial floors, tunnel linings, shortcrete applications, and other high-stress environments.

CFRP involves applying carbon fiberreinforced polymer strips or sheets externally to the concrete structure. It provides high strength-to-weight ratio, enhances load-carrying capacity,

Each type of precast concrete reinforcement offers specific advantages based on project requirements, design considerations, and desired performance characteristics.

August 2023 • Constrofacilitator

PRECAST REINFORCEMENT

Applications of precast concrete reinforcement

durability to withstand heavy equipment and machinery loads.

9. Foundation Systems: -

Precast reinforcement finds diverse applications across various construction projects. Here are some key applications where precast reinforcement is commonly used:

5. Retaining Walls: -

Used for retaining wall elements to enhance their stability, resist lateral pressures from soil, and prevent wall failure.

1. Architectural Elements:

11. Culverts and Drainage Systems -

6. Sound Barriers: -

Used for creating decorative architectural panels, cladding, and facades.

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2. Structural Components: -

Beams, columns, and girders in buildings and bridges are reinforced to withstand loads and resist bending and shear forces.

7. Tunnels and Underground Structures: -

3. Bridge Construction: -

Used in the fabrication of bridge components such as beams, piers, abutments, and decks.

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Used in industrial flooring applications, providing strength and

Used in constructing tunnel segments and other underground structures, ensuring their stability and durability over time.

8. Precast Stairs and Ramps: -

4. Industrial Flooring:

Used in sound barriers along highways and transportation corridors to reduce noise pollution for nearby residents.

Reinforced precast stairs and ramps provide safe and efficient access between different levels of a building or structure.

Used in foundation systems, including pile caps, footings, and mat foundations, to distribute loads and prevent settlement.

Used in culverts and drainage systems to create durable & efficient water management solutions.

12. Precast Modular Housing: -

Used in the construction of modular housing units, providing rapid and cost-effective building solutions.

Conclusion Precast concrete reinforcement holds a pivotal role in elevating the overall strength, longevity, and effectiveness of precast concrete elements. By leveraging sophisticated materials, careful planning, and accurate manufacturing methods, precast concrete reinforcement presents a flexible solution that addresses a wide array of structural needs. Through the utilization of advanced materials, meticulous design, and precise manufacturing techniques, precast concrete reinforcement offers a versatile solution that caters to a diverse range of structural requirements. The integration of precast elements with traditional concrete systems fosters synergy, allowing for the creation of resilient and aesthetically appealing structures that withstand the test of time.

August 2023 • Constrofacilitator

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PRECAST CONSTRUCTION

Benefits and Challenges of Precast Construction Er. Shamanth Kumar M, Managing Director, Skanda Group of Constructions

ABSTRACT Most of the construction activities in India take place by the conventional cast in situ method of construction. But still, there is a huge demand for housing in India. So the construction activity has to take place in a much faster way. This cannot be achieved by the conventional method of construction. It can be done possible with precast concrete construction. Moreover, there are more advantages of precast concrete construction over conventional one. Precast engineering's unique approach to construction brings a new facet to civil engineering as well as contributes opportunities to the transportation sector of the country. Undoubtedly it is one of the most beneficial techniques in construction and hopefully shall become a leader in the development of housing and metropolitan of our country. The following study analyses different aspects including precast construction materials, designing, and calculations as well as economic advantages and limitation of precast construction engineering INTRODUCTION The concept of precast (also known as “prefabricated”) construction includes those buildings, where the majority of structural components are standardized and produced in plants in a location away from the building, and then transported to the site for assembly. These components are manufactured by industrial methods based on mass production to build a large number of buildings in a short time at a low cost. The precast con-

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crete industry is largely dominated by Government initiated projects for infrastructural development. However, these are also being extensively used for residential (low and high rise) and commercial constructions because of their various favorable attributes. The efficiency, durability, ease, cost-effectiveness, and sustainable properties of these products have brought a revolutionary shift in the time consumed in the construction of any structure. The construction industry is a huge energy-consuming industry, and precast concrete products are and will continue to be more energy-efficient than their counterparts. The wide range of designs, colors, and structural options that these products provide is also making it a favorable choice for its consumers. Precast concrete is a construction product produced by casting concrete in a reusable mold or "form" which is then cured in a controlled environment, transported to the construction site, and lifted into place. Many state and federal transportation projects in the United States require precast concrete suppliers to be certified by either the Architectural Precast Association (APA), National Precast Concrete Association (NPCA), or Precast Prestressed Concrete Institute (PCI). Materials used for precast concrete structures are concrete, steel reinforcement, structural steel & bolts, and Noncontentious material (Elastomeric bearings for Neoprene, rubbers & mastic are used for soft bearings pads, backing strips, etc). If one sees from the beginning, Dr. Jacqueline Glass found that in the historical background of precast concrete, mainly of European countries, difAugust 2023 • Constrofacilitator

PRECAST CONSTRUCTION

ferent features like fire resistance, thermal mass, durability, acoustic insulation of precast concrete on building got discussed. There are many different types of precast concrete forming systems for architectural applications, differing in size, function, and cost. In 2002, M S Palanichamy et al, the maximum carpet area for the same plinth area is achieved by the use of lesser thickness of wall panels. By 2012 it was finally found that a common problem was the connection between the beam to column and column to base due to poor connection. The prefabrication is lightweight and has a thermal insulation property, easy work-ability, and economy in cost, easy availability. Using a precast concrete system offers many potential advantages over onsite casting. As for time affective. Precast concrete production is performed on the ground level, which helps with safety throughout a project. There is greater control over material quality and workmanship in a precast plant compared to a construction site. The forms used in a precast plant can be reused hundreds to thousands of times before they have to be replaced, often making it cheaper than onsite casting when looking at the cost per unit of formwork. The main features of this construction process are as follows: Ÿ Ÿ

Ÿ

The division and specialization of the human workforce. The use of tools, machinery, and other equipment, usually automated, in the production of standard, interchangeable parts, and products. Compared to site-cast concrete, the precast concrete erection is faster and less affected by adverse weather conditions.

Precast Beam and Girders

Ÿ

Plant casting allows increased efficiency, highquality control, and greater control on finishes.

This type of construction requires a restructuring of the entire conventional construction process to enable interaction between the design phase and production planning to improve and speed up construction. BENEFITS The use of precast concrete may have many advantages over regular methods of construction. After reviewing the statements stated above, the following benefits were found: Ø

Ø

Ø

Ø Precast Slabs

August 2023 • Constrofacilitator

The main advantage of the prefabricated method is the celerity by which the construction process takes place. Rapid urbanization, a tremendous shortage of skilled labor, and the need for having hassle free construction methods is a trigger to offer prefab technology to build homes faster. Another great advantage of prefabrication is durability. These prefab houses show better performance as they undergo a strict checking mechanism that ensures the product comes out to be defect-proof. These types of houses can be customized to specific needs/demands/requirements thus making it ideal than residing in conventional slums. These specific needs may include fire/ water/ soundproofing. Lesser waste is generated due to planned construction.

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PRECAST CONSTRUCTION

Precast Columns

Precast wall

Ø Ø Ø Ø Ø Ø

Process unaffected by adverse climatic conditions such as rainfall, snowfall, and heat. Requires less labor as compared to traditional forms. Utilization of cheap labor forces away from the construction site. Greater project certainty. Safer working environment. Reduced air and noise pollution at the construction site, especially useful when the site is situated near densely populated cities.

CHALLENGES India is experiencing a huge housing crisis today. The current housing shortage estimates to about six crore units. While many developing countries are struggling with the housing crisis, many developed countries have tamed this problem with precast concrete technology. Precast concrete construction technology is one of the promising solutions to meet the huge housing demand.

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The use of precast concrete systems offers several advantages such as fast and quality construction and enhanced health and safety. Despite these advantages, the industry has not gained popularity in India. To identify the major current challenges faced by the precast construction industry, a round table discussion among various stakeholders was held at IIT Madras. The article summarizes the proceedings of the meeting and brings out the critical issues associated with the precast concrete industry in India. The findings indicate that the lack of standardization, certification and testing facilities, contractual issues and taxation, non-availability of tools, technology, and equipment, limited knowledge, and lack of government incentives and promotion are some of the major challenges faced by the precast concrete construction industry. The article also discusses an action plan to alleviate the current precast concrete construction scenario. Housing types in India vary significantly and can reflect the varying socioeconomic mix of its vast population. The housing sector is the second largest employment generator and contributes about six percent of India's gross domestic product (GDP). The sector with 250 ancillary industries, has the potential to generate significant employment opportunities. However, several structural issues such as high fees, taxes, and limited and expensive capital have restricted the desired growth concerning housing demand. As per studies conducted by the a Ministry of Rural Development and the Ministry of Housing and Urban Poverty Alleviation, it is estimated that almost a quarter of Indian households lack adequate housing facilities. The central and several state governments in the past have undertaken various steps to mitigate the urban housing deficit. These efforts have yielded notable results. While efforts taken in the past are commendable, they have to be accelerated to eliminate the housing deficit. Acknowledging the importance of the housing issue in the country, the Central Government has launched a massive campaign in June 2015 which promises to provide housing to all its citizens by the year 2024. According to the Report of the Technical Group on Urban Housing Shortage (20122017) (Ministry of Housing and Urban Poverty Alleviation), Rural Housing for XII Five Year Plan (2012-2017) (Ministry of Rural Development, Government of India,

August 2023 • Constrofacilitator

PRECAST CONSTRUCTION

2011) and KPMG analysis in India (KPMG, 2014), the development of this ambitious program requires about 11 crore houses by 2024 with investments of over USD 2 trillion. The urban housing accounts for about 85-90 percent of the total investments and the affordable housing requirement is about 70 percent of total investments. To meet this huge urban housing demand, the precast concrete construction industry can play a crucial role. In a developing country like India, it is necessary to fulfill the present need of the infrastructure. Government investing a large amount about 40-50% of the total budget. While constructing the various buildings that may be commercial, residential, or any other building for achieving the fast and desired quality precast concrete/construction technology is used nowadays in India. And this technology is at an initial stage i.e. it cannot be used as a primary technology in India because it has some problems. Which are arising during the perengineering work, staking of the members, transporting, and erection and at various construction stages, etc. CONCLUSION The precast construction technology offers advantages such as a) b) c) d) e) f)

cost-saving. Time savings. Quality enhancement. Less labor required. Enhanced safety. Reduced wastage.

But the implementation of Precast technology in the Indian construction industry has some challenges as discussed in the results above. The proper measures should be adopted to promote precast technology in India. The government should take initiative in this regard. Despite having the advantages mentioned above, companies are not following the technique as several precast concrete elements manufacturing units or industries are very few in India, so dependability on the supply of precast elements is very high and they find it very risky. The setup of a precast yard requires a very high initial investment, so in India, investors should pro-

August 2023 • Constrofacilitator

mote this technology. Precast engineering although has certain criteria for its execution that include proper roads and transportation's to carry the constructions from the factory to the site without any damage or hazard. Precast engineering as an ideal mode of construction for energy efficiency and sustaining resources requires skilled groups of labor in adequate numbers to handle and monitor the execution of the precast constructions. One may conclude that precast engineering adds to economic development via its criteria by providing development and employment opportunities to India's economy. In today's world country's like the U.S, China, and Australia, etc, have successfully adopted the precast construction technique whereas India being a developing country has failed to render be the benefit of precast construction due to its transformational and geographical hardships. However, one cannot be neglect the advantages of a pollution-free and hazard avoidance environment offered by the precast construction. Therefore if the near future looks forward to the development of precast construction in the housings sector of the country, the benefits will prove to be a boon for Indian civil engineering. About Author The author is the Managing Director at Skanda Group of Constructions. He is an experienced Civil Engineer with a demonstrated history of working in the construction industry. He is skilled in AutoCAD, Construction, Management, Concrete, and Structural Analysis.

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PRECAST CONCRETE ERECTION METHOD

An overview precast concrete erection methods and equipments

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recast concrete erection is an important phase in precast construction where precisely engineered components come together to form robust and effective structures. This process involves installing precast concrete elements, including walls, columns, beams, and slabs, at the construction site. Careful planning and precise execution are essential because any mis-

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alignment or error during the erection phase could jeopardise the overall stability of the building. Using efficient erection sequences not only accelerates construction schedules but also reduces expenses and minimizes disruptions to the surrounding environment.

tion of Precast and Prestressed Concrete Elements. It covers detailed design, workshop drawings, the sequence of work, quality control, tolerances, risk assessment, risk mitigation, housekeeping, and safety measures during the erection process. Pre-Construction Activities

Method Statement for Erection of Precast & Prestressed Elements The method statement outlines the procedure to be followed for the erec-

Before assembly, a kick-off meeting must be held, with participation from all involved parties, including the crane company. All decisions and August 2023 • Constrofacilitator

PRECAST CONCRETE ERECTION METHOD

agreements made during this kickoff meeting must be documented during the start-up phase. It's important to ensure that the contracting company can demonstrate compliance with training requirements. Start-up meetings should be repeated when new employers or subcontractors enter the site. The purpose of the general start-up meeting is to ensure that everyone has a comprehensive understanding of safety procedures at the site.

Specific topics that should be reviewed and agreed upon include:

Ÿ Ÿ

Ÿ Ÿ Ÿ Ÿ Ÿ

During the kick-off meeting, the following topics must be addressed at a minimum:

Ÿ Ÿ

Ÿ Ÿ Ÿ

Ÿ Ÿ Ÿ Ÿ Ÿ Ÿ

Time and process plans Interfaces and coordination between different parties involved Clarification of responsibilities for establishing and maintaining traffic and access roads Clarification of responsibilities for common security measures Identification of any special risks Review and completion of the health and safety plan Guidelines for transferring and changing contracts Discussion of planned technical aids Determination of winter measures and responsible parties

August 2023 • Constrofacilitator

Ÿ

Ÿ

Ÿ Ÿ

Ÿ

Ÿ Ÿ

Supplier's instructions, particularly focusing on specific elements and their weights Compliance with this Site Erection guidance Receiving items from the supplier, including delivery times Delivery and assembly sequence Control points for receiving and assembly Stabilization of individual elements The overall temporary bracing (shoring plan) Installation of temporary fencing and hedges Use of technical equipment such as lifts, mobile scaffolding, ladders, cranes, and element supports Lifting gear, bolts, and anchors Prioritization of crane usage (relevant when multiple cranes operate in the same area) Maintenance and inspection of technical equipment and lifting gear Procedures for discarding items Assembly and dismantling of large element supports and transporting them out of buildings

Special items require additional precautions and attention. Control points must be defined for receiving and assembling each type of element.

Construction Activity - General Ÿ Ÿ

Ÿ

Ÿ

Use a mobile crane with sufficient capacity for erection. Lift Precast/prestressed concrete elements using provided lifting anchors, proper tools, lifting slings, and safety devices. Conduct a survey of the area to receive Precast/prestressed concrete segments to check for any dimensional or level differences exceeding tolerances. Inspect Precast/prestressed concrete segments before erection by subcontractor Erection Engineer/Supervisor and Engineer.

Transportation and Delivery to Site Ÿ

Ÿ

Ÿ

Transport Precast/prestressed concrete elements to the site only after QC final inspection and approval. Use flatbed trailers, low bed trailers, and "A" frame trailers, typically 12-15 meters in length. Support elements on the trailer using special belts or steel chains

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PRECAST CONCRETE ERECTION METHOD

Ÿ

Ÿ

Ÿ

Ÿ

Ÿ

fixed to the trailer. Provide wooden wedges/polystyrene bottom and side support if needed to prevent breakages. Handle loading, transportation, and offloading carefully to avoid major damage. Use suitable mobile cranes for loading and unloading, stacking elements in steel racks as per standards. Utilize appropriate lifting devices/slings/equipment for loading and offloading. Determine crane capacity based on element weight and required boom length. Erect barricades and place signboards in the lifting area to prevent unauthorized access. During longer operations, maintain proper signboards or assign a competent person to direct people away from the crane boom. For shorter operations, use a competent person to direct people.

Ÿ

Ÿ

Ÿ

Ÿ

Ÿ

Ÿ

Ÿ

Ÿ

Scaffolding and Temporary Work Ÿ

Ÿ

Ÿ

If Precast/prestressed concrete elements are stored at the site, keep them as close to the crane as possible to minimize double handling. Prepare access roads for receiv-

tions and drawings for Engineer review and approval.

Field Survey

Storage at Site Ÿ

ing trailers transporting the Precast/prestressed concrete units. Ensure elements are delivered in the required sequence for continuous erection. Wall and façade elements are typically stored with their long sides horizontal.

Ÿ

Conduct a field survey and stakeout of existing cast-in-situ dimensions for accurate placement of Precast/prestressed concrete elements. Verify the location, orientation, and level of bearing pads, M&E service accessories, dowel bars connecting panels to slabs, and benchmark levels. Establish precise work positions based on control points shown on the panels and agreed upon with the Engineer's surveyors. Provide grid lines for each zone and benchmark level. Survey dowel bars connecting panels to slabs. Ensure slab or raft levels are within tolerance (zero gap to a maximum of 30 mm between panels & slab and rafts). Use special materials if tolerances are exceeded. Submit all necessary computa-

Ÿ

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Securely support and anchor Precast elements before and upon placement. Provide safe working platforms where needed to allow easy access for workers to produce quality connection details. Coordinate scaffolding placement with the main contractor for accessibility to other work areas. Use scaffolding mainly for temporary support, alignment, grouting, finishing, or element fixing. Ladders may be used for certain conditions, such as grouting.

Different Erection Methods 1. Erection - Slab (Hollow Core/ Form Slab): - Hollow Core Slab: -

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Hollow core slabs are precast concrete elements with hollow channels or cores running longitudinally through them. These cores reduce the slab's August 2023 • Constrofacilitator

PRECAST CONCRETE ERECTION METHOD

Different Equipments, Safety Platforms and Barriers Used For Site Erection of Precast Elements Lifting Equipment

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weight while maintaining its structural integrity, making them suitable for long spans. Installation involves cranes or lifting equipment placing the hollow core slabs onto supporting structures like beams or walls. Hollow core slabs are commonly used for floors in buildings such as apartments, offices, and parking garages.

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Form Slab (Solid Slab):

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Form slabs, also known as solid slabs, are precast concrete slabs that are solid throughout, without any hollow cores. They are typically used for shorter spans and are heavier than hollow core slabs. Installation involves placing these slabs directly on the support structure, such as beams or walls. Form slabs are often used in residential construction or where shorter spans are acceptable.

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2. Erection - Precast Beam: -

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Precast beams are structural components that support the load of the building above, such as floors or roofs. Installation usually involves placing precast beams horizontally onto columns or other support-

August 2023 • Constrofacilitator

ing elements. 3. Erection - Precast Column or Foundation: -

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Precast columns are vertical structural elements used to support the structure above the ground level, including the superstructure and roof. Installation typically involves setting precast columns onto prepared foundation footings. Precast columns are commonly used in various building types, including commercial and industrial projects, where speed and consistency are essential.

All lifting gear must have CE marking, including the lifting points in the elements when they are part of a lifting system (and marked as such).All lifting brackets and other lifting gear should be clearly marked with a safe working load (SWL) indicating the maximum allowed load. Crane and lifting hooks and shackles can also be marked with the chain/hook dimension. The equipment should be kept clean. Different types of lifting equipment includes.

Shackles Shackles should be clearly marked. Industrial shackles should not be used. The screw should only be Repairs -

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To address any general defects in precast/prestressed concrete elements, employ approved repair materials or equipmentapproved materials. Execute repairs following the manufacturer's recommendations.

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PRECAST CONCRETE ERECTION METHOD

lightly tightened by hand to prevent excessive tension in the bracket. Bolts and nuts should always be secured with a splint. Lift Mandrels Lift mandrels should match the lifting hole in the element and the element's weight. They must be secured to prevent the loop from slipping off. The loop/chain should be as close to the element as possible to prevent bending of the mandrel. Mandrels weighing a maximum of 12 kg should be removed from the ladder.

Lifting Yoke / Assembly Winch

any other securing device capable of safely supporting the load in case of a malfunction.

A Lifting Yoke / Assembly Winch should be employed when fitting positions necessitate vertical lifting.

Lifting of Elements Loop of Steel Wire Ropes

For adjustable yokes with rope anchoring, the permissible load depends on the angle of the loops concerning the horizontal position.

Loops should be equipped with eyelets featuring securely pressed safety ropes produced in specialized workshops. If screw caps are utilized, it is crucial to follow the supplier's instructions. The specified load capacity applies to individual loops for vertical lifting. For composite loops, the load capacity is contingent on the angle between the loops. During the unrolling of long steel wire rope loops, take care to avoid kinking, as this can potentially damage the steel rope during tensioning. Loops

Lifting Scissors and Eye Bolts

Clamping Bracket

These are used for fitting hoisting bolts and permitted screws. Ensure that the nut or bolt head provides sufficient contact surface. Only eye bolts, ring nuts, and fixed ring bolts from recognized manufacturers marked with SWL/WLL (Safe Working Load) may be used. Avoid using rolled threads in combination with cut threads.

Clamping Brackets are utilized for assembling ceiling elements and should be tailored to the size, type, and weight of the elements. The positioning of the bracket clamps should adhere to the instructions provided by the element supplier. These brackets should always be equipped with safety chains (round slings and hoisting slings should not be used) or

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The load-bearing capacity of loops and chains is influenced by the angle of inclination. The length of the loops

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PRECAST CONCRETE ERECTION METHOD

can be calculated based on the distance between the sling point and the angle of inclination. When using 4 loops for fastening, load calculations should consider only two loops, ensuring they can collectively support the entire load along with the associated embedded transport anchors. Round Slings/Lifting Slings Slings crafted from synthetic fibers should not be used under high mechanical stress or in extreme heat or cold conditions. Protect them from direct sunlight. Chain Sling For hoisting, only chains with certification should be used. The chain should not be twisted while under load and should be free of "knots." Shortening should be done using a shortening claw with a safety device. The angle of inclination must not exceed 60 degrees.

Assembly equipment A safe and efficient workplace requires appropriate equipment to ensure stable and secure assembly. Defective equipment should never be used. Any damaged ladders, scaffoldings, supporting devices, elevators, etc., should be promptly removed from the site. In unfavorable weather conditions such as strong wind or precipitation, assembly should be temporarily halted. However, it's essential to ensure that all elements are adequately supported. Several equipments and platforms can be employed for this purpose that includes; MEWPs MEWPs can be used regardless of the working height during assembly, fastening, and support. Its movements should be controlled from the basket. Individuals inside the basket should be secured with a harness and lifeline. MEWPs should be used, tested, and maintained according to the manufacturer's instructions.

crane's lifting capacity. The crane's lifting and lowering speed should not exceed 0.3 m/s. A radiotelephony link should be established between the crane and the basket. The use of a crane basket should be a last resort, as it is not the preferred method of transportation. When using two cranes for common lifting, careful planning is essential. A competent person should oversee the operation to prevent misunderstandings between the crane operators. Both cranes should ideally have identical constructions and velocity regulation. The load should never exceed 75% of the capacity of each crane. If necessary, special equipment must be used to ensure proper weight distribution and vertical lifting. Ladders Ladders provide the lowest level of safety and should be used sparingly. Before using a ladder, it should be visually inspected for damage. A damaged ladder should not be used. Reg-

Personnel Transport with Crane The basket is suspended from a fixed rack or 4 loops/chains, attached at least 1 meter above the ground. The total weight of the basket and its contents must not exceed 1000 kg, which should not surpass 25% of the August 2023 • Constrofacilitator

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PRECAST CONCRETE ERECTION METHOD

ular inspections of all ladders are necessary.

tance of technical aids, such as a crane.

Placement of Ladders

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Ladders should be properly positioned on a solid, flat surface at an angle of 60-70 degrees with anti-slip protection. It is advisable to secure the ladder to the object it leans on and place an object in front of the ladder to prevent it from slipping. This is mandatory in some countries. Working on Ladders Ladders should only be used for carrying lightweight and easily manageable loads, such as drills, ceiling connections, and supporting devices. Only activities that can be performed with one hand are allowed, and the reach should not exceed an arm's length. Leaning to the side is prohibited. Ladders as Access When ladders are used for access, they should be secured and extend at least 1 meter above the access point. Fall protection should be installed on the edge to prevent falls when accessing or exiting the ladder. Scaffolding All scaffolding should be erected following the supplier's assembly instructions, which should include information on bracing requirements and the intended use of the scaffolding. Scaffoldings and work platforms above 2 meters in height should have a 1-meter-high railing consist-

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ing of hand, knee, and foot skirting, as well as a full-length and width scaffolding floor. The erection and inspection of scaffolding should adhere to local legislation and the requirements outlined in Life Saving Rules. Mobile scaffolds must have all wheels locked during work, and no one should be present on a mobile scaffold while it's being moved. Support Equipment Supports should not be removed until the building or construction phase reaches its final stabilization, unless approved by the project manager or supplier. Different types of support equipment include:

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Supports should be removed using a lift and lowered along the wall, with movement controlled simultaneously using a rope from the basket (no one is allowed under the support after the splint has been removed and lowering has begun). In situations where space allows, such as in large halls, technical aids like a tractor or truck crane may be employed.

Fastening Sleeves and Screws Fastening sleeves and screws, typically made of class 8 steel, should be designed to match the size of the elements. Ensure that the assembly contractor has all the necessary information regarding their holding capacity and strength.

Handling Support Equipment Support equipment weighing up to 25 kg can be manually handled by one person, unless local regulations state otherwise. Equipment weighing between 26 to 45 kg may be manually handled by two individuals. Support equipment exceeding 45 kg should be handled with the assis-

Rails, Covering, and Barriers Fall protection measures, such as rails, covering, and barriers, are crucial for safety during assembly work to prevent falls from heights. These precautions should be implemented as early as possible in the process. -

Fall protection is mandatory when working at heights of up to

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PRECAST CONCRETE ERECTION METHOD

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2.5 meters unless local legislation specifies otherwise. In multi-story buildings, rails along the façades should be designed to minimize the opening for mounting. Barriers must consist of two guard rails (at hip and knee height) with a toe board. Rails along edges are not required if work or access occurs at least 2 meters away from the edge. Local standards, if higher, should be followed. In such cases, clear and durable markings should be used, like cones and boards; plastic bands are not suitable.

Door Openings and Holes Door openings, elevator shafts, and holes in floors and floor slabs should be fitted with rails or covered immediately after the holes appear. Covering should ideally be done before element delivery; otherwise, it should be done right after element mounting. Coverings should be securely fastened, either by screws or by being secured against displacement with slats at the bottom. Attachment of Balusters Baluster suppliers should provide mounting instructions, including screw size and quality, which should not include commercial screws. PPE (Personnel Protection Equipment) When working in assembly, personAugust 2023 • Constrofacilitator

nel must wear a helmet, highvisibility safety vest, and safety shoes. Eye protection, such as welding goggles or a face shield, should be worn during welding. Goggles or a visor are needed when working with an angle polisher or during hacking, drilling, or cutting.

Retractable Belts and Fall Tackles Short safety lines or retractable belts, possibly combined with a security sling, are preferred when possible. If more movement space is needed, use a fall tackle. Ensure proper orientation for the type of fall tackle being used.

When dealing with dust from concrete, brick, and stone products that contain crystalline silica, use a dust mask or other breathing apparatus if dust cannot be removed at the source. Fall Protection Attachment points for fall protection equipment must withstand a pull force of at least 10 kN (1000 kg).

Fall Absorber

Safety Lines Safety lines should be made of steel wire to prevent cutting by sharp concrete edges.

A fall absorber functions as a brake during a fall and should be appropriately sized for the line. Security Slings Security slings are steel wire ropes used on rib roof panels. A short safety line is attached to them with snap hooks to move around on the roof. If two persons attached to the same security sling need to pass each other, at least one person must have a second safety sling to maintain safety.

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PRECAST CONCRETE ERECTION METHOD

Assembly Order and Special Elements Ensure that elements, pillars, ceilings, and other components are delivered in the correct order for assembly. If items are delivered out of order, decide whether to reload or return them. In unforeseen situations where items have been unloaded incorrectly, consult with the project engineer, erection manager, and safety team to find an acceptable solution.

ping as special elements and secure them against tipping. Facades and Walls -

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Fastening and Hoisting -

Fastening can be accomplished from a ladder or an element. Ensure that the crane operator has left the area before lifting. Make sure that no one is in harm's way during lifting and assembly.

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strength. Unload the pillar, attach lifting equipment, hoist it into an upright position, and install it either directly on the foundation (pendulum pillar) or embed it (clamped pillar). Pillars should be placed on level fiber blocks, metal plates, bolt heads, or embedded in a molded cushion. Pendulum pillars should have two supports stiffened at the 2/3point, forming a right angle to each other, to prevent rotation. Supports should only be removed after the concrete has fully cured or when the pillars are adequately loaded.

Beams and Support -

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Pillar Assembly -

Prior to assembly, pillar base plates must possess sufficient

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Ensure that pillars or elements they support are stable and possess the necessary strength. Use tall, slender beams or soft, movable supports to prevent tipping. Identify beams susceptible to tip-

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Facade assembly in multi-story buildings should commence from the uppermost floor plate. Load elements symmetrically to prevent uneven weight distribution on the frame transporter. Employ diagonal supports to withstand wind loads.

Turning of Elements -

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If elements need to be turned over before assembly, equip the crane with two independent hoists and a pulley. Ensure the proper placement of lifting anchors on the element's longitudinal side according to supplier instructions.

Asymmetric Elements -

Identify asymmetric elements as special and discuss their assembly and support during the introductory meeting.

Ceiling Elements -

Before fitting ceiling elements, ensure that the supporting structure base is molded, hardened, or August 2023 • Constrofacilitator

PRECAST CONCRETE ERECTION METHOD

Corrugated Sheet -

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possesses sufficient load-bearing capacity. Use rails when the fall height is 2.5 meters or more (or as per local legislation). Promptly cover holes in ceilings, ideally before element delivery.

sheet supports, and gable-ceiling elements to ensure stability.

Securely fasten corrugated sheets on the ground and lift them using a special bracket. Employ a security sling during assembly.

Install rails along the gable and ends of the first support row.

Dismantling of Precast Elements -

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When dismantling elements during construction, proceed in reverse order while ensuring temporary stability and safety. Consult with a designer knowledgeable about the building structure before dismantling elements.

Rib Roof Panels -

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Prior to mounting TT and TTS supports, ensure that the supporting structure's base is prepared or possesses the necessary loadbearing capacity. Utilize control ropes to guide elements during the lift. Never position the lift/ladder under the element during assembly.

Welding -

Weld carrier connections, beampillow connections, corrugated

Conclusion Precast concrete erection requires meticulous planning, skilled labour, use of right equipment and strict adherence to safety protocols. This method efficiently streamlines construction processes, enhancing structural integrity and mitigating on-site risks.

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PRECAST CONCRETE DEMAND AND APPLICATIONS

Precast Concrete Elements used for Infrastructure Projects; Demand and Applications

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he demand for precast concrete in infrastructure projects has been steadily increasing due to its advantages such as speed of construction, cost-effectiveness, and durability. It's widely used in applications like bridges, tunnels, highways etc. With rapid urbanisation and population growth, the need for swift and reliable construction solutions has intensified. Precast concrete offers a compelling advantage in this context, as its

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off-site manufacturing and quick assembly significantly expedite project timelines. Additionally, its superior quality control and durability contribute to the longevity of infrastructure, reducing maintenance and replacement costs over time. Moreover, the environmental benefits associated with reduced on-site construction waste and resource consumption have further fueled the adoption of precast concrete as a sustainable choice for modern infrastructure development.

As per rationslat.com, the precast concrete market in India has expanded significantly. Although exact numbers for market size differ, industry estimates and assessments suggest that the sector has recently reached a valuation of between US$ 225 and 300 million. This estimate accounts for initiatives in the public and private sectors, spanning a range of industries and market categories, including infrastructure. The modularity and versatility of precast components cater to a wide array of infrastructure needs, including August 2023 • Constrofacilitator

PRECAST CONCRETE DEMAND AND APPLICATIONS

bridges, tunnels, flyovers, and wastewater treatment facilities. This adaptability, coupled with its ability to withstand harsh environmental conditions and seismic events, has made precast concrete a preferred choice in regions prone to natural disasters. As technology continues to advance, innovations in design and manufacturing techniques are likely to further enhance the appeal of precast concrete, cementing its position as a cornerstone in the construction of modern and sustainable infrastructure. Why the demand for precast concrete for infrastructure? The demand for precast concrete elements in infrastructure projects has been steadily growing due to its numerous benefits.

August 2023 • Constrofacilitator

1. Speed: Faster construction due to off-site manufacturing.

8. Aesthetics: Can be finished with a variety of textures.

2. Durability: Long lifespan due to precise production in controlled environments.

Precast concrete elements for infrastructure projects

3. Design Versatility: Customizable shapes and sizes for diverse needs. 4. Sustainability: Lower waste, energy use, and recyclable materials. 5. Rapid Deployment: Minimises disruptions to traffic and nearby residents. 6. Safety: Fewer on-site construction risks. 7. Consistency: Uniform quality across all components.

Precast concrete elements find extensive application in a variety of infrastructure projects due to its versatility and benefits. Here is an overview of different types of precast concrete products used for infrastructure applications: 1. Bridges: Precast concrete components are used to construct efficient and durable bridge structures. These components are fabricated off-site and assembled quickly, reducing onsite disruptions Its applications include;

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PRECAST CONCRETE DEMAND AND APPLICATIONS

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Precast Bridge Beams: Preformed beams used to support bridge decks. Girders: Large horizontal beams supporting bridge spans. Deck Panels: Prefabricated segments that form the bridge roadway. Abutments and Piers: Structural elements that support the ends and middle of bridges.

2. Highways and Roads; Precast elements are used to enhance road safety and separate traffic flows. Its applications include; -

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Precast Pavement Panels: Readyto-install roadway sections for quick construction. Traffic Barriers and Parapets: Safety barriers along roadways and

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bridges. 3. Tunnels: Tunnel segments made from precast concrete provide a strong and durable lining for tunnels. They can be customised to accommodate different tunnel shapes and sizes. Its applications include; -

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Tunnel Lining Segments: Precast segments are used for lining the inside of tunnels. Subway Tunnel Segments: Specifically designed precast elements for subway systems.

4. Railways: Precast components are used to ensure stability, safety, and efficiency for rail systems. Its applications include -

Precast Railway Sleepers (Ties) Pre-

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formed slabs that support railroad tracks. Platform Components: Precast sections for train station platforms.

5. Ports and Harbors: Precast concrete is used for constructing quay walls, breakwaters, and other structures that require durability in harsh marine environments. Its applications include; -

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Dock and Pier Components: Precast elements for marine construction, including port facilities. Breakwater Structures: Precast barriers used to protect coastlines from wave action.

6. Water Treatment Plants: Precast concrete components such as tanks, pipes, and treatment structures are used for water and wastewater treatment facili-

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PRECAST CONCRETE DEMAND AND APPLICATIONS

ties. Its applications include; -

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Water Storage Tanks: Large precast tanks for storing water in municipal systems. Wastewater Treatment Structures: Precast components for sewage treatment facilities.

7. Utility Structures: Precast is used for constructing utility vaults, sewer systems, and other underground utility structures. Its applications include; -

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Manholes and Catch Basins: Access points to underground drainage systems. Box Culverts: Precast concrete boxes used for water conveyance. Stormwater Chambers: Performed elements for stormwater management. Utility Vaults and Chambers: Enclosures for utility equipment such as electrical, telecommunication, and water supply components.

8. Decorative and Architectural Elements: Precast concrete products offer versatile applications and in urban landscape. Its applications include; -

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Precast Planters: These planters come in various shapes, sizes, and designs, offering an attractive way to incorporate greenery into urban spaces. Bollards: Act as protective barriers and also serve as design elements that define spaces, pathways, and vehicle access points.

Conclusion The demand for precast concrete is expected to continue growing in infrastructure projects. Governments and private developers are recognizing the value of precast components in delivering projects on time, within budget, and with high quality. This demand is likely to be particularly strong in areas with rapidly growing urban populations and the need for modernized and efficient infrastructure. August 2023 • Constrofacilitator

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PRECAST CONCRETE PRODUCTS

Different types of precast concrete products and their uses

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recast concrete products play a pivotal role in modern construction, offering a streamlined and efficient approach to building infrastructure and structures. These products, manufactured off-site under controlled conditions, ensure consistent quality and precision, reducing on-site construction time and labor. Their importance lies in the ability to accelerate project timelines, enhance structural

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integrity, and provide design flexibility. Precast products encompass a wide range of applications, from foundations and structural elements to walls, drainage systems, and architectural features. DIFFERENT TYPES OF PRECAST CONCRETE PRODUCTS Precast concrete foundation products Precast foundation products offer efficient and durable solutions for vari-

ous construction projects. 1. Isolated Footing: Also known as pad footing, it's a rectangular or circular concrete slab that supports individual columns. These footings are premanufactured and can speed up construction by reducing on-site concrete work. 2. Pocket Footing: Similar to isolated footings, pocket footings have an added feature of recesses or pockets on the top surface. These pockets are designed to accommodate column August 2023 • Constrofacilitator

PRECAST CONCRETE PRODUCTS

bases securely, providing stability and ease of assembly. 3. Precast Piles: These are vertical structural elements driven into the ground to support loads. Precast concrete piles are manufactured off-site and then driven or drilled into the ground, providing a quick and reliable foundation solution. 4. Strip Footing: A longer and narrower concrete strip used to support a line of columns. Precast strip footings can be interconnected for ease of installation and improved load distribution. 5. Raft Foundation: A large concrete slab that covers the entire area under a building. While not always precast, some variations may involve precast elements to simplify the construction process. 6. Pier Foundation: Consists of cylindrical columns (piers) that support the structure. Precast pier founda-

Precast concrete foundation

August 2023 • Constrofacilitator

Advantages of Precast Concrete Products

Safety

Environmental Benefits

Quality Control

Time Saving

Design Flexibility

tions can be made with high precision and installed rapidly. 7. Helical Piles: These are precast concrete or steel piles with helical plates. They are screwed into the ground and provide anchoring for foundations in a variety of soil conditions. 8. Micropiles: These types of piles come with a smaller diameter. Pre-

Durability

cast micropiles are often used in limited-access areas and for retrofitting existing structures. Precast concrete beam products 1. RCC Beams (Reinforced Concrete Beams): These beams are traditional reinforced concrete elements used to support loads in buildings and structures. They are manufactured off-site and can be customized for different lengths, depths, and loadbearing capacities. These beams are designed with steel reinforcement bars to enhance their strength and durability. 2. Prestressed Beams: These beams are designed to withstand significant loads and provide superior structural performance. They are manufactured with high-strength concrete and tensioned steel strands, which help counteract potential tensile forces. Prestressed beams are often used in long-span structures such as bridges and parking garages.

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PRECAST CONCRETE PRODUCTS

3. Shell Beams: Also known as thinshell beams, have a curved or shelllike cross-section. They offer an elegant and efficient solution for spanning long distances while minimizing material usage. Precast shell beams can be used in roofs, canopies, and architectural features. 4. Tee Beams: These beams have a Tshaped cross-section and are commonly used in bridge construction and other applications where structural efficiency is important. Precast tee beams can be manufactured in various sizes and configurations to accommodate specific design requirements. 5. L-Beams: These beams have an Lshaped cross-section and are often used in retaining walls, bridge abutments, and other situations where a horizontal element needs to support

vertical loads. Precast L-beams are versatile and can be designed to meet different loading conditions. 6. Box Beams: These beams consist of a rectangular or box-shaped cross-section and are used for various applications, including bridge decks, culverts, and elevated roadways. Precast box beams offer ease of installation and can be customized to fit project specifications. 7. Spandrel Beams: These beams are typically used in buildings to support the space between windows and doors, often in curtain wall systems. Precast spandrel beams can incorporate architectural finishes and detailing to match the design aesthetics of the structure. 8. Inverted T-Beams: These beams have an upside-down T-shaped

cross-section, with the flange at the bottom. They are commonly used in parking garages and other structures where the bottom flange provides support for a slab. Precast inverted Tbeams can speed up construction and provide efficient load distribution. 9. I-Beams: These beams have an Ishaped cross-section and are widely used in industrial and commercial buildings. They offer a balance between structural efficiency and aesthetic appeal, and can be manufactured with varying lengths and load capacities. Precast concrete slab products 1. RCC Slabs (Reinforced Concrete Slabs): These slabs are traditional reinforced concrete elements used as floor and roof systems in buildings

Precast concrete beam

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PRECAST CONCRETE PRODUCTS

and structures. They are manufactured off-site and can be customized for different spans and load-bearing capacities. These slabs are designed with steel reinforcement to enhance their strength and durability. 2. Prestressed Hollow Core Slabs: These slabs are widely used for flooring and roofing in commercial, residential, and industrial buildings. These slabs have a series of voids or cores that reduce weight while maintaining structural strength. Highstrength steel strands are tensioned before casting to counteract potential tensile forces. Hollow core slabs offer rapid installation and allow for the passage of utilities through the voids. 3. Single Tee Slabs: These slabs have a T-shaped cross-section and are commonly used in parking garages, commercial buildings, and industrial facilities. They provide efficient spans and load-bearing capabilities. Precast single tee slabs are designed for

Precast concrete wall

August 2023 • Constrofacilitator

ease of installation and can be customized to suit specific project requirements. 4. Double Tee Slabs: These slabs consist of two flanges connected by a central stem, creating a double Tshaped cross-section. They are commonly used for flooring and roofing in large open spaces, such as sports facilities, warehouses, and parking structures. Precast double tee slabs offer wide spans and rapid installation, making them suitable for projects with tight schedules. 5. Ribbed Slabs: These slabs consist of a series of closely spaced ribs with a flat top surface. They are designed to reduce the overall weight of the slab while maintaining structural integrity. Precast ribbed slabs are used in situations where longer spans and greater load-carrying capacities are needed. 6. Waffle Slabs: These slabs have a grid-like pattern of ribs and beams,

creating a waffle-like appearance on the underside of the slab. This design increases the slab's load-bearing capacity while reducing its weight. Precast waffle slabs are suitable for larger spans and can provide an aesthetic ceiling finish. Precast concrete wall products Precast concrete products offer versatile and efficient solutions for various types of walls in construction, including both load-bearing and nonload-bearing walls. Here's an overview of precast products commonly used for different types of walls: Load-Bearing Precast Wall Products: 1. Precast Load-Bearing Wall Panels: These panels are designed to carry structural loads and can serve as both exterior and interior walls. They are manufactured off-site and can be customized with insulation, finishes, and openings for doors and windows.

2. Shear Walls: The shear walls are used to resist lateral forces such as wind and seismic loads. They provide stability to the structure and can be integrated into the building's architectural design.

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PRECAST CONCRETE PRODUCTS

ciency and reducing thermal bridging. They are suitable for both loadbearing and non-load-bearing applications.

3. Composite Wall Panels: These panels consist of a precast concrete layer connected to an insulation layer, providing both structural support and thermal insulation. They are commonly used in energy-efficient and sustainable building designs.

4. Insulated Wall Panels: This type of precast wall panels incorporate insulation material within the panel, improving the building's energy effi-

5. Architectural Facade Panels: These precast panels are designed to enhance the aesthetics of a building's exterior. They can mimic various materials such as stone, brick, or wood while offering the benefits of precast concrete.

6. Sandwich Wall Panels: Sandwich panels consist of two layers of precast concrete with insulation in between. They are efficient for both load-bearing and non-load-bearing walls, providing structural integrity and thermal performance.

tecting the structure from the elements. 2. Partition Walls: These partition walls are used to divide interior spaces within a building. They can be load-bearing or non-load-bearing and offer flexibility in layout and design.

3. Curtain Wall Panels: These panels are used in curtain wall systems to create an external envelope of a building. Precast curtain wall panels provide a combination of aesthetics, weatherproofing, and insulation.

Non-Load-Bearing Precast Wall Products: 1. Cladding Panels: These cladding panels are used as decorative elements on the exterior of buildings. They can add texture, colour, and visual interest to the façade while pro-

4. Retaining Wall Panels: These type of retaining wall panels are used to create retaining structures for earth retention and slope stabilization. They are often used in landscaping and infrastructure projects.

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PRECAST CONCRETE PRODUCTS

4. Insulated Roof Panels: These roof panels combine precast concrete with insulating materials, providing excellent thermal performance. These panels contribute to energy efficiency by reducing heat transfer through the roof.

5. Fire Separation Walls: These walls provide fire-resistant barriers between different parts of a building or between adjacent buildings. They help prevent the spread of fire and protect occupants.

that can be designed to fit specific project requirements. They are available in various shapes, sizes, and finishes, including plain, textured, or patterned surfaces. Precast roof panels are known for their durability, weather resistance, and ease of installation. 2. Roof Beams and Joists: These types of concrete beams and joists provide support for the roof structure. These elements are designed to carry the weight of the roof and any additional loads while ensuring stability and structural integrity.

6. Decorative Wall Panels: The panels can be used to create unique design elements, such as textured surfaces, patterns, and reliefs, both indoors and outdoors.

3. Architectural Cladding Panels: These panels serve a dual purpose by functioning as roofing material and exterior cladding. They come in a variety of finishes and styles, enhancing the aesthetic appeal of the building while providing a durable roofing solution.

Precast concrete roof products 1. Precast Roof Panels: These panels are large sections of roofing material August 2023 • Constrofacilitator

Others types of precast concrete products Precast concrete products can be used for various construction needs beyond just foundations, structural elements, and walls. Here's an overview of precast products commonly used for different purposes: 1. Precast Staircases: Manufactured off-site and can be customized for various architectural designs. They offer efficient and safe access between different levels of a building and can include finishes, railings, and landings.

2. Box Culverts: Used for stormwater drainage, underground passage for streams, and road crossings. They provide a cost-effective solution with

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PRECAST CONCRETE PRODUCTS

5. Manholes: Used to access underground utility networks, such as sewer systems and pipelines. They provide a safe and convenient entry point for maintenance and inspections.

8. Traffic Barriers: Precast traffic barriers are installed along roadways to enhance safety by preventing vehicle crossovers and directing traffic flow. They are commonly used on highways and bridges.

quick installation, enhancing water management infrastructure. 3. Underground Sumps: Designed to collect and manage stormwater or wastewater. They are commonly used in residential, commercial, and industrial settings to control water runoff and prevent flooding.

6. Catch Basins: Installed to collect stormwater and prevent debris from entering the drainage system. They play a crucial role in managing surface water runoff.

9. Jersey Barriers: Used as temporary or permanent dividers between lanes of traffic or to protect construction sites. They are highly visible and provide impact protection.

4. Septic Tanks: Precast septic tanks are an essential component of onsite wastewater treatment systems. They provide effective treatment and disposal of household sewage, ensuring proper sanitation and environmental protection.

7. Utility Vaults: Precast utility vaults are used to house various utility equipment, such as electrical components, telecommunication devices, and water meters. They provide protection and easy access for maintenance.

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10. Precast Pavers: Used for walkways, patios, and driveways. They come in various colours, shapes, and textures, allowing for creative land-

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PRECAST CONCRETE PRODUCTS

scape design. 11. Retaining Wall Blocks: Used to create retaining walls for landscaping and erosion control. They offer an aesthetically pleasing solution while preventing soil erosion. Conclusion The widespread adoption of precast concrete products marks a transformative shift in the construction landscape. Their adaptability and customization options empower architects and engineers to bring their creative visions to life while maintaining structural integrity. As the demand for innovative and efficient construction solutions continues to rise, precast concrete products emerge as a cornerstone of prog-

ress, embodying the synergy between technology, design, and responsible development. In a dynamic world where time, precision,

and sustainability converge, precast products stand as a testament to human ingenuity and the evolution of construction practices.

Centre pushes for precast material in highway projects Amidst deliberations over mandatory usage of precast concrete elements in national highway projects, the Union Ministry of Road Transport and Highways (MoRTH) has started pushing developers to employ construction components produced in controlled factory environments. The ministry, through an office memorandum, recently made attempts to persuade construction companies involved in the development of the national highways in this regard, saying that it will help all stakeholders in the long run. The ministry, on April 1 this year, decided to mandatorily use 25 per cent factory-manufactured concrete elements, out of the total volume, other than the foundation work in projects initiated within a 100 km radius of the

August 2023 • Constrofacilitator

precast concrete factory. The aim was a reduction of pollution at construction sites, rapid progress and improved aesthetics. Speaking at the National Conference for Civil Engineers and Professionals from Allied Industries in August, Union Road Transport and Highways Minister Nitin Gadkari reiterated that the government wanted to make precast mandatory at least in Road under Bridges and Road over Bridges. Along with the memo issued on Thursday, the ministry has also circulated among the agencies carrying out highway development a two-page note on the benefits of industrialised precast concrete elements. “Precast concrete has the benefits of allweather and fast construction, reliable quality and enhanced performance dura-

bility, aesthetics due to uniformity in appearance, minimum construction time, reduced carbon emission, and reduced noise and air pollution due to reduced construction activities at the site. To add to that, it will also play an integral role in accelerating the growth of the MSME (Micro, Small and Medium Enterprises) sector,” read the memorandum sent to all senior officials of the ministry, National Highways Authority of India, National Highways and Infrastructure Development Corporation Limited and the National Highway Builders Federation.

Source: newindianexpress.com

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