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Modern Construction Techniques
- P Nageswara Rao GM - Operations Process Plant Construction Business, L&T
This paper looks into some of the new strategies or methods which have evolved over the years in the field of industrial construction, and has changed the face of the industry for better.

Construction industry is the second largest industry in India after agriculture. The industry continues to face multiple challenges ranging from macroeconomic factors viz volatile economic growth, governance issues, capital market worries etc to lack of talent viz relevant skillset. While Innovation and improvement in technology is the key to tide over such times, one of the charges leveled at the construction industry, as at the beginning of the 21st century, is that it has a poor record on innovation, when compared with manufacturing industries such as aerospace or electronics.

Every new strategy or method is compared with existing one in terms of cost, time and effort by the stakeholders before being adopted. A company, which can successfully use modern techniques to deliver projects within time and cost without compromising on safety and quality, will stay ahead of competition.

Modern Construction Techniques
Various modern construction techniques can be mapped into three major categories ie
  • Technological Enablers - New viable technologies
  • Operational (methods/processes) Enablers - Integration of Technology to define the process/method
  • Skill Enablers - Identify the critical skills for these technologies and put in place systems for acquiring these skills
Technological Enablers
These enablers predominately focus on innovations in the field of science and technology:
Self-compacting Concrete: Self-consolidating Concrete or Self-compacting Concrete (SCC) is characterised by a low yield, high deformability, and moderate viscosity necessary to ensure uniform suspension of solid particles during transportation, placement (without external compaction), and thereafter until the concrete sets.

This concrete can be used for casting heavily reinforced sections, places, where there can be no access to vibrators for compaction and in complex shapes of formwork which may otherwise be impossible to cast, giving a far superior surface than conventional concrete.

Although costly, the productivity economics of the material makes it a favorite of 'precast industry.'
Advanced Welding Processes & Nondestructive Techniques (NDT):
Construction companies constantly endeavor for improvement in welding technologies and non-destructive technique used for construction in oil and gas industry.
Welding is a major activity in the construction of plants. All pipes and most of the structure connection are joined by welding technique. Shielded Metal Arc Welding (SMAW) is being widely used; however, this method suffers from irregular arc and poor weld quality. With development in technology, high speed welding processes with capability to produce superior quality welds have replaced the SMAW process. Some such processes are semi-automatic FCAW, orbital welding, Surface Tension Transfer (STT), Submerged Arc Welding (SAW).

Another area where construction industry lacked speed and safe operation was radiography. Radiography was done by taking x-ray of the weld joint - the images were then developed on the films and reviewed for weld defects. The key concern in this process from safety point of view is the source used to take radiography films; the source is radioactive and requires separate bunker. Also, the method suffers from various lacunas viz:
  • Time taken in the process
  • Quality of films which is dependent on the skill of radiography person
  • Poor quality films requiring lot of retakes
  • Post radiography separate records of joint has to be maintained for approval, this further increase the time for checking and approving welded joints
The introduction of close proximity radiography and phased array ultrasonic testing which is completely safe for operation has dramatically improved the cycle time for radiography and data management. The technology is also reliable in determining the type and position of weld defect. This method can be used for wide range of material making it suitable for construction industry. (Refer Figure 2)
Slip-form and System Form Work: This technology is used for concreting work. This type of formwork has higher production rate by enabling mass concreting at single point of time. In the construction industry these are considered pillars of modern day architecture as far as product quality and finishing goes. Apart from that, it provides huge saving on manpower requirement along with improved HSE performance.

Pre-cast construction: Over the years, pre-cast construction has come a long way due to its key benefit of time-saving. With focus on fast project execution, without compromising on safety and quality, pre-cast construction has become norm of the day.

Operational Enablers
Continuous pressure to comply with international standards (HSE, Construction Methods etc) coupled with increasing complexity of plants over decreasing plot sizes and aggressive project schedules is making construction companies to constantly invest in various process improvement initiatives. Lack of sufficient area for executing various activities like bar bending and cutting, mechanical fabrication works, etc, have led to the idea of executing various works on a shop-floor mode i e doing it off line with a manufacturing set-up.
Some of such operational enablers are:
Rebar Processing Plant: Modern day rebar processing plants are as good as movable factories bringing the best of both worlds viz project construction management and manufacturing onto one plane. These methods offer wide variety of advantages over the conventional methods. Some of them are:
  • Faster production rates
  • Fewer number of defects resulting in better quality
  • Optimised use of material resulting in less wastage
  • Last but not the least, an improved HSE performance
Automated Pipe Spool Fabrication
Process plant piping is considered the nervous system of a plant. Plant piping helps transport various fluids viz oil, water etc from one end of plant to other. This maze of piping across the plant is formed by welding various spools (typically a combination of one pipe with welded fittings viz bends, valves etc at either end). An automated pipe spool shop is another step in the direction of bringing best of manufacturing practices to construction sector. It typically consists of machines like fit-up, profile cutting, blasting and painting to speed up the production of spools. Combined with modern-day welding methods like orbital welding machines etc, this sort of manufacturing setup provides a good degree of flexibility in handling pipes of various diameters and thickness over different material range. Some of the key benefits are:
  • Higher productivity and reduced wastages
  • Improved safety and quality performance
  • Consideration for supply side constraints viz. delivery of raw materials on time
Modularisation of Structure: The early construction methods followed stick approach for completing the structures. In this method individual members were lifted in sequence and placed on the existing member. This method is slow and requires considerable effort and resources. Nowadays using software tools structure is broken into modules and support members are provided at required level in the module. The whole module is assembled on ground and erected as a single equipment using cranes. This execution methodology offers the flexibility to outsource the fabrication of structure member to manufacturing shop. This is now a widely adopted practice by construction companies.

Information Technology: IT serves as a thread running thru beads (various construction activities), enabling exchange of information and providing a birdĘs eye view to top management. It makes the system transparent and systematic. Further, it eliminates need for depending on any key person carrying for information thereby establishing process flow for each activity. This will offer scope for continuous improvement and improve overall operational efficiency.

Skill Enablers
With an existing demand and supply constraint for skilled manpower, ever-increasing wages, use of newer technology and processes, increased complexity of work, the need to enhance various skills are of prime importance. In order to bring awareness and enhance skills of various levels, dedicated training systems should be implemented.

Safe working practices and a safe working environment are the first and foremost requirements at any construction site. Any kind of loss towards men or material will eventually harm the project progress. It is the responsibility of the employer to establish safe work methods and to create a safe working place. In order to achieve excellence and successfully complete the project it is important for the industry as a whole to institutionalise strong safety practices in day-to-day work.

Conclusion
In the construction business, opportunities are abound, but capitalising on them has never been more challenging. In a constantly changing business environment, we must continually find new ways to respond to challenges. In the recent times, India has stepped up its development agenda. One explicit indicator of this is the aggressive pace of construction activity in the country. Use of various new technologies and deployment of project management strategies has made it possible to undertake projects of mega scale. Technocrats associated with the Indian construction industry need to employ innovative technologies and skilled project handling strategies to stay competitive and be the market leader.