Mechanization in Construction of Housing and Commercial Infrastructure

A massive growth is taking place in India in the infrastructure segments. From the year 2000 a growth at 9% per annum has been consistently recorded and it is expected to continue and grow further. We have seen the growth kick started by the golden quadrilateral project followed by the rehabilitation of large number of slums in many major metros. The reality boom in the country is by product of our success from the IT sectors and other fast growing services. The Planning Commission is all set to layout a lions–share of the total budget allocations for the rural infrastructure along with large number of power projects. With the growth in the field of infrastructure, several new challenges have emerged in various forms and these can be listed as:

1. Massive scale and number of the projects
2. Stringent time stipulations
3. Quality and safety insistence from the promoters
4. Unimaginable and unexpected rise/jump in the prices of commodities (steel, cement, bricks, sand etc.) essentially required for the infrastructure project development.
5. Alternate processes and looking at out of box solutions which have become the order of the day.

Some of them have emerged with

1. alternative methods in construction
2. choosing alternative materials to overcome the scarcity and reducing the expenditure
3. mechanization at the sites, using latest modern equipment and techniques

In most of the cases, the purchase departments of organisations go by the indents raised by the project in charge. The project in charge usually comes up with what he knows rather than what he wants. Most of the time the entire team ends up in buying what the manufacturer has to offer rather than getting what best the project requires.

In the past few years, the efforts of the organized bodies like builders association are able to provide exposure and opportunities to the contractors, planners and builders a global view of how their counterparts across the world are working, the latest trends in the equipment by attending the international Engineering and Equipment Exhibitions.

Thus there is a need to streamline and get into a direction where the challenges are addressed through the professional approach. The approach should be scientific in nature; the basis should be explainable and should stand the test on the projects sites through speed, safety, and savings. Environment may also be a factor while considering a process, material and equipment.

All of these exercises should prepare the engineering community to face the unprecedented growth when the mass rural and urban housing projects take off, in very near future.

Scope

The scaling of operations have changed at least by 200 to 300% if not more. Individual bungalows have grown into gated communities. The size of the communities is spreading across from 5 acres to 400 acres of development. The projects boast of 65 houses to 600 houses. The stand alone apartments have given way to Condominiums/societies with 85 flats to 800 flats in one compound. This was seen in the west like Mumbai and Pune. This is becoming a common site in Bangalore, Hyderabad, Chennai, Delhi, and Calcutta. Even in district headquarters and state capital the scene is changing very fast because of non–availability of land and highrise in cost.

The scarcity of labor has hit the construction industry very hard on every front. The volumes and sizes have forced the industry to look into alternative ways of approach. This has forced them to look for mechanization which is the only way to obtain speed, quality, and economy in our projects.

Every promoter is now aware of the machines available and have placed a lot of orders on batching units, tower cranes, Earthmovers etc.

So far mechanization is addressed in the areas of mass applicability and this is the only way to look at. Concrete batching and transportation equipment, steel rebar interims, earthwork, and material movements are few of the core activities.

Standardization vis–a–vis Mechanization

This a vital factor in the field of construction projects today and this subject needs to be pursued in totality. The bottleneck comes from the dependency on the skilled personnel at various stages of work. Identify the repetitive processes which can be performed with various tools and equipment thus reducing the intervention and dependency of the labor. Mechanization does not mean adding costs to the projects. Standardization is the methodology of using the similar components for further progress of work or parts of the projects.

One standard case in point

The formwork of the apartment structures can be standardized by investing about 15% more on the design and the initial set of plates/ plywood etc. expected and as has been decided.

Lets get the formwork designed and fabrication as units for Kitchen, Hall, bed 1, bed 2, toilet, staircase etc…and allow the process to be repeated for the next 15 to 30 floors. This is not a new systems, most of the progressive contracting houses are already adopting some of these practices.

Applicability & Selection Criteria

Concreting

We have concrete mixing and batching equipment in market with capacity ranging between batching units from one bag mixers (3CuM/hr) up to 120CuM /Hr. Depending on the work value and volume, we have to decide which equipment to be chosen and installed to suit for particular project.

Case in Point: Inframax Project: Haffezpet, Hyderabad Clock Layout of inframax project (PDF).

Volume of work : 3.2 million sft Area Nature of work: A p a r t m e n t s – 6 Blocks (G-2 & G+14) and commercial single block (350 x 280 ft) complex (G-3 & G+12)

Project completion time deadlines: 30 months from the time of start Requirement of concrete : 180Cum /per day

Peak requirement : 240Cum 3 times a week

In this project, we have designed concrete production for the peak requirements. We have finalized on one unit of 30CuM batching plant and one unit of 18CuM batching. We had to adopt this arrangement keeping in view of the peak and low requirements and also to have a standby arrangement in case of any unforeseen breakdown circumstances.

Material Handling

Broadly, we bifurcate them into two separate categories; for Horizontal and Vertical movement. These can be determined by Structure sizes: Area of floor, Height of the structure, Layout of the structures and limitations if any at the site.

Horizontal Movement

The usual horizontal movement of equipment on the site are Tractors with attachments, Loaders, Dumpers, Site trucks/Tough riders and various types of trolleys and Wheel Barrows. There are various techniques and methods for horizontal movement on the floors, during carpentry, fixing and fitting of steel and also for concreting of columns.

Here the warehousing (Yards for steel, cement and the place of concrete batching) plays a major role. Depending on the horizontal movement (distance) on the floor and the weight/quantities for the structure, we can select and choose from the equipment available in stock from rental companies or from market. During the construction of superstructure and finishing stages, there are lot of movements both in terms of horizontal and vertical material handling, and during these operations lot of economy can be obtained.

Methodology & Selection Criteria for the Horizontal Material Handling

Case in point: Infra Max

Horizontal movements have to be designed for input to the batching plant. The steel movement from the yard to the respective structures, Bricks from the yard to the respective structures, Tiles, doors, windows, Bathrooms etc. to reach the respective structures, and of–course movement of small equipment like vibrator, compactors, plastering machines etc.

We have suggested the management with the following equipment:

Front end dumper	:	4
Tractor loaders	:	3
JCB	:	2
Tractors	:	2

Wheel barrows and trolleys in good number 24.

Vertical Material Handling

The vertical movements are generally structure specific. The equipment generally used in terms of vertical material handling would be winches, Tower hoists, Passenger & Material hoists, Tower cranes etc.

The vertical material handling depends on many features:

• Size of the structures
• Location of the structures
• Approach to construction (planning)
• Completion time frames

Selection criteria should be considered after enlisting

• Capability of the equipment
• Limitations of the equipment like power need, size weight etc
• Limitations of the site for the usage of this equipment
• Various applications due to be performed by the said equipment

Case in Point: Sun City Projects

Overview of the project (Parikrama Architects View)

Parikrama Housing: Panchakula, Haryana

Volume of work: 4 million Sq.ft Area

Nature of work: Apartments 24 Blocks (G-2 & G+19) & Service amenities

Project time deadlines: 30 months from the time of start

Peak requirement: 90 tonnes of material per day per tower and 400 to 600 people to be transported per day per tower.

Tower Crane

For example, lets take the study for the application of the Tower crane. Capabilities of the Crane: (5013) Jib Radius 50Mts Tip loads @1.3 tones, which can carry loads from 6 tonnes upto a radius of 30mts and will place any material within the given radius. It is mainly used to carry Steel, Centering and shuttering equipment, and concrete through buckets.

Advantages

• Can carry literally anything to the top surface of the structure.
• Picks up and places anything anywhere within the given radius
• Very dependable

The suggestions made for this site are to go with a twin cage P & M Hoist per tower by taking care of the entire Vertical material handling.

Value

We have gone through various case studies and the conclusions on the recommended equipment at the sites. These recommendations are mostly based on the value it creates in terms of Speed, Safety, Savings, and Strength.

Speed

How fast are we going to handle the material? Have we taken into considerations, various processes at the site which may have to be performed simultaneously!

Have we considered and addressed the bottlenecks in these processes?

Safety

Is the safety factor addressed? Is the equipment. Are any precautions to be taken before, during and after the installation of the said equipment in point safe to handle.

Savings

Proper suitability evaluation and selection of the equipment and the accessories will lead to cost savings.

For example, spending say $12,000 more on a VVVF (Variable Voltage and Variable frequency drive) for a P&M Hoist, It will save you on the Capital equipment such as Generators. Such a device would save the running costs throughout its life of operations.

Strength

What strengths are we going to add to the sites, by introducing the tower crane?

The management needs to address the change in project management in lieu of the new processes & the equipment that are chosen for the project.

Emphasis on training should be addressed across all level of the management. Inducting new departments like planning and services (mechanical) would help to see the benefits of the mechanization at projects.

The selection of suitable equipment is to be carried out scientifically and has to be given due importance and priority. This involves meticulous planning, Knowledge of alternate processes and in depth knowledge about the range of equipment available and its sources.