Ankana Ganguly General Manager – Specification and Technical, STP Ltd.
An ammunition depot is a military storage facility for live ammunitions and explosives. The storage of live ammunition and explosives are inherently hazardous. There is the potential for accidents in the unloading, packing, and transfer of ammunition. Great care is taken in handling these dangerous explosives so as not to harm personnel or nearby ammunition. Generally, to avoid any kind of static on the floor, the installation of antistatic epoxy flooring is a must. We have almost completed the flooring work of 3240 sq m successfully. It was not just a project to us, but it was a great honor to be a part of the project of such high stature.
Actually, an Anti-static industrial floor inhibits the generation of electrostatic discharge, which is the pulse of static electricity that happens when a charged person or surface comes into contact with another object. The discharge may be visible as a spark or tiny blue bolt of electricity, although the majority of static electricity is not usually apparent.
Cleaning and maintenance is very important for an anti static epoxy flooring. There are a range of off the shelf anti-static cleaning products available, they work in exactly the same way as a standard floor cleaning chemical but include an anti-static additive that attracts moisture from the atmosphere that eliminates static build up. To further emphasis the importance of correct cleaning it is worth adding that many standard cleaning chemicals can actually increase the risk or propensity to static build up. It is highly recommended that you use a neutral PH cleaning chemical so that you do not add either a positively charged layer over the top of your floor surface.
Furthermore static will build up quicker on a dirty floor, the friction caused by the rubbing of the sole of a shoe and the dust and dirt on the floor will create static. A good and regular cleaning regime using the correct cleaning chemicals will ensure a static free floor. Moreover, right type of shoes is very important. The reason you build up static electricity usually comes from walking on an insulated surface with certain types of insulating shoes, especially when the weather / room humidity is very dry. We would strongly recommend that you avoid trainers or any shoes with rubber soles. Leather soles are good and for the best solution use either anti-static or even better ESD footwear. Providing the correct footwear is a far more cost effective solution that installing a full ESD flooring if you don’t need one!!!!
The method of installation of an anti static floor includes the following steps:
Surface Preparation
All Substrates should be dry (max. 5% moisture content), clean, sound and free of laitance. Surface grinders and shot blasting are used to prepare the surface; the surface should be properly cleaned and should be free from dust prior to application of primer.
Priming
It is imperative that the Primer-contents are thoroughly premixed prior to mixing together. The contents are mixed slowly using a slow speed drill and paddle for at least 4 minutes. Primer is then applied on the dry concrete surface @ 0.2 to 0.25Kg/per square meter by Brush/Roller.
Use of a screed sometimes is optional.
Laying of Copper Tape
A copper strip of required width and thickness is laid. The butter paper is firstly removed and the adhesive side of the copper strip is kept exposed. Stick the self-adhesive copper strip on to the clean primed substrate at a distance of 1 to 4 meter to each other, lengthwise and breadth wise.
At the periphery, near to the walls, stick the self-adhesive copper strip at a distance of 6 inches from the walls. At any one end in the room, copper strip should be extended out for connection of earthing.
Base Coat
It is a three component self leveling system which is natural black in color. Base coat should be applied after drying of the Primer (usually after 6 – 8 hrs. from application of primer).
Top Coat
Top Coat is a three component self leveling system. There is a wide range of colors available for that and Technical department should be contacted for choosing the best suited color for a particular surrounding. Top coat is applied just after the drying of base coat. A gap of at least 12 hrs should be maintained for application of topcoat.
Precast concrete is a construction product produced by casting concrete in a reusable mould or “form” which is then cured in a controlled environment. To ensure the good durability, high strength, low water cement ratio and improved rheology, use of concrete admixtures is compulsory.
Mapei offers Dynamon SX626 and Dynamon SX550, hyper-plasticising admixtures based on new generation of polycarboxlate ether. Dynamon SX626 / SX550 is a used waterproof and durable concrete with exposure class in compliance with EN206-1, ready mixed concrete with high mechanical performance and good acceleration in the development of mechanical strength, making the concrete pumpable.
Precast building is constructed by assembling and connecting various prefabricated elements required in the building structure. These elements are:
Precast Slabs
Precast Beams
Precast Columns
Precast Walls
Precast Foundations
Let us see the range of products Mapei offers for assembling and concreting these prefabricated elements to make a building:
Anchoring with Expansive Mortars and Fixing with Rapid Setting Binders
Excessive spanning of areas by pre-cast concrete foundation sections with no fill and no footing at all may lead to future water entry, floor slab settlement, or in severe cases, foundation movement. Spans over five feet would violate a Superior Walls guideline and other spans may be improper depending on the product and the engineering design for the project.
Mapefill GP – General purpose non-shrink grout. Mapefill GP is used for grouting voids in structural elements such as – patching up honeycombs in concrete, filling gaps in precast elements, and grouting base plates and bridge bearings.
Repair Precast Concrete with Mortars and Controlled Shrinkage Binders
Concrete is typically “restrained”, so changes in volume result in cracks because concrete is weak inn tensile. Volume changes occur due to chemical and autogenous shrinkage – both results in hydration.
Mapefer 1K – One-component corrosion-inhibiting cement mortar for the protection of reinforcing rods. Mapefer 1K also acts as adhesion improver for concrete repair mortars.
Planitop – R2-class, rapid-setting shrinkage-compensated, thixotropic, fibre-reinforced, cementitious mortar applied in a single layer from 3 to 40 mm thick, for repairing and smoothing concrete. Planitop is used for:
Quick repairs to deteriorated parts in concrete, the corners of beams, pillars, buffer walls, cornices and the front edges of balconies.
Quickly smoothing over surface defects in cast concrete, such as honeycombs, spacer holes, construction joints, etc., before painting the surface.
Repairing and smoothing over concrete mouldings on civil buildings, such as skirt roofs and protruding decorative elements.
Repairing pre-cast concrete structures
Repairing Cracked Precast Concrete by Injection Casting
Precast panels are reinforced for crack control and typically made of high-quality concrete with low water-to-cement ratios and very low water absorption. It is for these reasons that they can act as a reliable barrier to water penetration. Millions of square feet of precast panels installed over the last five decades have provided the real-life proof of this. However, the polymer sealants between panels and other components are susceptible to workmanship flaws during construction and slow deterioration over time.
Epojet LV – Epojet LV is a two-component epoxy adhesive. The pre-measured components (component A = resin and component B = hardener) must be mixed together before being used. Once mixed, Epojet LV becomes a very fluid liquid that can easily penetrate even in microcracks. Epojet LV polymerizes without any significant amount of shrinkage, also on wet surfaces and once hardened, it is waterproof and resists chemical agents present in the atmosphere.
Eporip – Monolithic construction joints between fresh and hardened concrete. Bonding precast concrete element and bonding steel to concrete. Filling cracks in concrete. Eporip is a solvent-free epoxy adhesive consisting of two pre-measured components (component A = resin, component B = hardener) that have to be mixed before use. Eporip has the consistency of a slightly thixotropic paste that can be applied by brush on both horizontal and vertical surfaces.
Adesilex PG – Two-component thixotropic epoxy adhesives for structural bonding used for Structural repair, bonding and reinforcement of concrete elements, natural stone, mortar and brick.
Waterproofing
Special basement waterproofing system details are needed if a basement de-watering system is installed after construction of a building with precast concrete foundations or walls.
Mapegum WPS – Quick-drying flexible liquid membrane for waterproofing internal surfaces. Waterproofing indoor floor and wall surfaces that are not subject to rising damp nor in permanent water immersion. Flexible, anti-fracture membrane. Apply before the installation of ceramic tiles or stone material. Mapegum WPS may be used on:
plasterboard, gypsum or cementitious render, lightweight cement block and marine-plywood;
cementitious, anhydrite, wooden and magnesite substrates and existing ceramic and natural stone after the application of Eco Prim T primer.
Mapelastic – Two-component cementitious mortar, flexible down to -20°C, for waterproofing balconies, terraces, bathrooms and swimming pools. Mapelastic is used for waterproofing and protection of concrete structures, renders and cementitious screeds.
Mapelastic Smart – Two-component, high-flexibility cementitious mortar (with crack-bridging capacity > 2 mm) applied by trowel or roller for waterproofing balconies, terraces, bathrooms and swimming pools. Mapelastic Smart is used to protect concrete structures, renders with hairline cracks and cementitious surfaces in general which, being subject to vibrations, may suffer from cracking.
Mapelastic Aquadefense – Ready-to-use, ultra-quick drying, flexible liquid membrane for internal and external waterproofing applications. Mapelastic Aquadefense is used to form waterproofing layers before applying ceramic, stone and mosaic coatings in: balconies and terraces; bathrooms and shower cubicles; laundry rooms; saunas and damp environments in general.
Sealants
Well detailed and constructed joints play a vital part in maintaining the integrity of the external envelope of the building, ensuring it is weatherproof and meeting any other requirements such as fire resistance and acoustic performance. It is recommended that joints be treated as a strong visual feature of architectural wall design. Recessing of joints and/or sealants will help diminish the visual impact of possible variations between adjacent surfaces.
Mapeflex PU45 – Mapeflex PU45 has been specially developed for sealing expansion and distribution joints in horizontal and vertical surfaces, including those which are subject to occasional chemical attack provoked by hydrocarbons. It is also recommended for flexible bonds between similar and different materials most commonly used in the building industry for both internal and external applications and as a replacement or to integrate mechanical fasteners.
Mapesil AC – Mapesil AC is an acetic-crosslinking silicone sealant suitable for sealing glass, ceramic and anodised aluminium. After first having used a bonding enhancer, Primer FD can also be used on concrete, wood, metal, painted surfaces, plastic and rubber.
Protection of Precast Concrete
Degradation of concrete includes the following common mechanisms: acidic reactions, alkaline reactions, chloride-induced deterioration and sulphate deterioration. Each is produced by different environmental conditions. Concrete is also highly alkaline and contains moisture, which can prevent a coating from adhering to the surface, curing properly or performing as needed.
Toilet POD
Assembled Precast Structure
Elastocolor – Elastomeric paint for crack-bridging protection used for Painting cracked façades and concrete structures subject to deformation.
Case History
Tunnel Formwork Type of Residential Project, Pune
The project consultant was awarded with the design and implementation of precast segments and cast-in-situ concrete of M60 grade in the BOQ. With many trials, Mapei India came up with the required admixture for the project and Dynamon SX626 was used for the GCC + 13 Floors structure.
Aurobindo Realty & Infrastructure has adopted precast technology to speed-up construction processes and take advantage of the development boom in Hyderabad, which is home to about seven million people, and is one of the speediest developing cities in India. Numerous IT companies have their headquarters here and many infrastructure projects are being developed.
Aurobindo Realty, when faced with the dilemma of creating modern sleek buildings with minimum time and manpower, and more secure environment for construction workers, began to explore alternate construction methods. “With conventional systems, we would have faced the challenge of getting skilled manpower, besides having to deal with high attrition, site logistics and safety issues,” said Ravindra Kumar VJ, Chief Executive of Aurobindo Realty.
“In fact, most construction companies in India are faced with similar problems,” he noted. “These challenges, coupled with project requirements are leading to cost and time overruns in projects along with huge costs in rectifying any defects.”
The company executives began to consider alternatives for construction over the traditional methods and soon discovered the advantages of precast construction, which empowers quicker project execution at twice the speed of traditional construction and over 50 percent reduction in labour prerequisites. “We soon realized that using precast enables high quality and uniform products produced in a controlled environment. The other main gain is in construction time due to advantages of speed and consistency,” said Kumar.
Adopting precast technology for Aurobindo implied lessening in labor, timely project completion and fewer wastage of materials – all of which gave the company a competitive edge. The company chose Elematic precast technology from Finland, which offered state of the art plants, proven technology and machineries that are being used across the globe, and complete end-to-end services.
Aurobindo soon finalized a 21-acre land in Sanga Reddy district of Hyderabad for setting up the precast plant. But the work was far from over. “We are providing a full gamut of services from setting up the plant, training the company’s team for efficient operations, as well as having an annual maintenance contract to ensure full production,” said Chander Dutta, Managing Director of Elematic India.
Presently, Aurobindo is on its way to reach its goal of completing its first project called Galaxy – a 24-story commercial tower located at the busy industrial hub of HITEC city. The company is also launching two more projects which will also use precast construction – Orbit, a 24-story tower at HITEC city and Lulu Mall – an Emirates-based mall operator. Aurobindo’s precast plant is already on an expansion mode. It has installed a third beam line to augment its production capacity and to meet the increased demand from their sites.
Adopting precast method of construction bodes well not just for Aurobindo but for the Indian construction industry as a whole. With successful examples such as Aurobindo, the construction sector is set to see accelerated usage of precast technology and superior quality of buildings in the years to come.
For further information,
contact: shridhar.rao@elematic.com
The force of static friction is responsible for keeping the feet in place. If a little force is applied to push an object horizontally, static friction is an equal and opposite force that keeps the object at rest. If a greater force is applied the static friction is increased to match the force. The object moves if the static friction force is maximum. The static friction coefficient (μ) between two solid surfaces is defined as the ratio of the tangential force (F) required to produce sliding divided by the normal force between the surfaces (N)μ = F /N For a horizontal surface the horizontal force (F) to move a solid resting on a flat surface F= μ x solid mass x g.
If a body rests on an incline plane the body is prevented from sliding down because of the frictional resistance. If the angle of the plane is increased there will be an angle at which the body begins to slide down the plane. This is the angle of repose and the tangent of this angle is the same as the coefficient of friction.
The above theory is closely related with our daily life …………
Our placed feet grip the floor and push backward, that causes the floor to push forward on your foot. This is termed «grippy» type of friction, where the surfaces are prevented from slipping across each other, a static frictional force.
This is the root cause of fatal accident that happens unfortunately on finished marble or granite floor. You’ve probably experienced having information that caused you observant to avoid accidents on marble floor that mostly happens in toilets. Slips generally take place either when the heel of the ‘front’ foot lands or as the sole of the ‘rear’ foot pushes off. Usually people fall almost exactly over the same location.
The accident happens on glossy, polished and shiny floor which is slippery. We use granite tiles in common places like public stairs, etc. Our reflex action makes us conscious while walking on this surface. You may feel even you amble in such places. That helps us in choosing the right flooring material.
Today’s most popular flooring materials are marble, ceramic tiles, Porcelain tiles of different types of attractive finishes and wooden floors. etc. as floors are a significant design refresher, as well as an investment that can increase the value of house.
Wooden floors can develop scrapes, scratches and dents over time and incur moisture damage. However most of the expensive shining flooring material is low-absorbent and non-absorbent because of the less porosities. That is closely related with the foot fall effect. The floor surface which is none or less absorbent by property is slippery and we know that coefficient is a measurement of the relative ability of various surfaces to resist the sliding or slipping of the selected material. Occupational Safety & Health Administration (OSHA) currently recommends that the static coefficient of friction should be at least 0.5 for all walkway surfaces under both wet and dry conditions. ASTM C1028 gives, through the use of a force gauge (horizontal dynamometer) pull meter method, the static friction coefficient of the surface.
Equal to or greater than .60 — excellent friction.
Equal to or greater than .50 — adequate.
Equal to or less than .40 — Caution necessary.
While choosing flooring material we should consider the frictional property of the product. There are various types of flooring materials are available in market. We should avoid slippery flooring for toilets and common places. There are anti-skid tiles which should be preferred for those areas. Manufacturers and sellers should suggest the right material for particular areas.
According to a report by World Health Organization falls are the second leading cause of accidental or unintentional injury deaths worldwide.
Each year an estimated 646 000 individuals die from falls globally of which over 80% are in low- and middle-income countries.
Adults older than 65 years of age suffer the greatest number of fatal falls.
3 million falls that are severe enough to require medical attention occur each year.
The above statistics shows the relevance of anti –skid floor.
Earlier we had no such technology to make a mirror finish floor. The marbles which was used in past, the walking surface was not polished. But, as the technology is advanced to meet the requirement of users, the surface technology is modified. But, today the advanced technology is focusing on the consciousness to choose the right material for safety.
The following flooring can be suggested for different locations in house.
1.Marble Flooring- This is good if not highly polished. Suitable for living room.
2. Vitrified Tiles- vitrified tiles are available in glossy, matte and anti-skid finishes.
3.Terrazzo Flooring- Good for home.
4.Quartz Flooring- Suitable for kitchen
5.Laminate Flooring-Suitable for bedroom, inexpensive.
6.Vinyl Tiles- Suitable for toilets.
7.IPS flooring stands for Indian patent stone flooring, it is a basic type of flooring which provides good wearing properties. It is generally used for all types of floors and mix of concrete used for IPS flooring specification is 1:1.5:3 (cement, sand and stone aggregates).This is inexpensive and adequate anti-skid property is achieved with proper maintenance. This can be grey or colored.
8.IPS Flooring with Nano Composite SYLOCON® which contains millions of Nano tubes that makes the surface antiskid, crack free and receives any colour.
9.Wooden Flooring- Expensive. Good for interior and dry zone.
10.Vacuum Dewatered flooring- Good for industrial heavy duty flooring.
There are immense scope to research on this subject to make the floor safe, attractive, ease of maintenance and durable. Safety is first priorit
To be continued……………..
For further information,
visit: www.aquacrete.co.in
Joint Venture Company Sassevaart is using a building information modelling (BIM) platform from Allplan – a global design software company – for the construction of the New Lock Terneuzen in the Netherlands.
Currently under construction and measuring 427m long, 55m wide, and 16.4m deep, New Lock Terneuzen will form part of the Rotterdam-Paris Inland Waterway. Designed for larger vessels, the lock is intended to increase the capacity of the shipping route, which is already said to be one of the busiest and most important navigated canals in Europe.
According to Allplan, the Bimplus platform gives all the project’s participants access to a central BIM model and enables the entire project team to easily review the reinforcement designs, provide feedback and assign and track tasks.
Due for completion in 2023, the lock will allow inland vessels “smoother” passage between Belgium, France and the Netherlands and will also provide a more “robust lock complex” for seafaring vessels.
