Chemical Bonding

01 Jul 2011 CW Staff

Chembond Chemicals Ltd offers a wide range of chemicals used in construction and civil engineering.

Founded in 1975,Chembond Chemicals Ltd, is headquartered out of Mumbai and focuses on the specialty chemicals segment.Operating four divisions construction chemicals, coatings, trading and biotechnology; and two joint ventures Henkel Chembond Surface Technologies Ltd and Chembond Ashland Water Technologies Ltd the company has an established presence across India and has been growing consistently over the years.

@Cemcon 2011
The company was an associate sponsor of Cemcon 2011, an international conference and exhibition on construction of high rise concrete buildings held in Pune between June 17 and 18, 2011. At the event, Deepak Kanitkar, Deputy General Manager made a presentation titled, ‘New Generation Concrete for Tall Structures with PCE’s and beyond’.

“Chembond’s construction chemicals have been in use in some of the most prestigious projects in India. We are proud to be associated with the Indian Concrete Institute as associate sponsor of Cemcon 2011," said Nirmal Shah, Joint Managing Director.“We welcomed all visitors and attendees to interact and discuss their technical challenges with us so that we may be able to come up with a solution to the same," said Kanitkar. “On display in our stall was a large part of our range of construction solutions encompassing areas like waterproofing, sealants, concrete and mortar admixtures, tile fixing adhesives, tile joint fillers and engineering grouts," said Mangesh Patil, Head Infrastructure Business.

repair
Meanwhile, concretes based on hydraulic binders such as Ordinary Portland cement have a common tendency to . injection using either Epoxy Resin or Polyurethane resin based grouts, is one of the most efficient and effective techniques used; separately discussed by Kanitkar, an expert in the field. Epoxy resins are used for structural repair while polyurethane resins are used in situations where movement is expected or water leakages have to be stopped quickly. Sometimes a combination of both materials may also be used. While formulating and recommending both materials, one must bear in mind that both are sensitive to water. Typically, epoxy resins have difficulty in setting and developing the desired strength in the presence of water. Polyurethane resins on the other hand are available in one, two or three pack systems. One pack resins generally foam in the presence of water, thus effecting quick stoppage of flowing water through s. Two and three pack systems offer either a flexible sealing solution or foam like single pack resins. The foam generated by such systems, is more flexible than the single pack resin.

Structural repair
Depending on the specific requirements of the job, repair by epoxy injection can restore structural integrity and reduce moisture penetration through concrete s 0.002 in. (0.05 mm) in width and greater. First, s must be cleaned from foreign matter before injection. Material selection is critical. Sometimes initial Polyurethane injection or use of cement based water plugs may be necessary to stop the flow of water. Injection equipment comprises air assisted guns, hand actuated delivery systems, and spring or balloon actuated capsules.

The procedure begins with the installation of injection ports at proper spacing generally at 40 mm in centre. s are then sealed through its length with suitable sealing material. Injection is carried out after the cap seal is set. After the injection is complete, the ports are removed. The cap seal may be completely removed using suitable procedure such as grinding or left in place, if it is not objectionable.

Non-structural repair
If the does not compromise the structural integrity of the structure, injection with polyurethane grouts or other nonstructural materials may be a more suitable choice to fill the . Mainly, two types of polyurethane based injection resins are used. One system is used for sealing dry or damp s and the other to stop the flowing water. Both single and two or three component systems may be used for generating foam. The foaming action is very quick. The dual component and three component resins may require multi component guns depending on the reaction time. Mixing and delivery of mixed materials must be well controlled. The repair procedure mostly remains the same like the one used for epoxy injection.

Health and safety
Both epoxies and polyurethanes are hazardous materials and must be handled with care. Jobsite safety practices should include, but not necessarily be limited to, the following:

lKeeping a copy of Material Safety Data Sheets (MSDS) on site.
lWearing protective clothing and protective eyewear where required.
lWearing rubber gloves or barrier creams for hand protection.
lHaving eye wash facilities available.
lWearing respirators where needed.
lProviding ventilation of closed spaces.
lSecured storage of hazardous materials.
lHaving necessary cleaning materials on hand and
lNotifying occupants of pending repair procedures.

Chembond Chemicals Ltd offers a wide range of chemicals used in construction and civil engineering.Founded in 1975,Chembond Chemicals Ltd, is headquartered out of Mumbai and focuses on the specialty chemicals segment.Operating four divisions construction chemicals, coatings, trading and biotechnology; and two joint ventures Henkel Chembond Surface Technologies Ltd and Chembond Ashland Water Technologies Ltd the company has an established presence across India and has been growing consistently over the years.@Cemcon 2011The company was an associate sponsor of Cemcon 2011, an international conference and exhibition on construction of high rise concrete buildings held in Pune between June 17 and 18, 2011. At the event, Deepak Kanitkar, Deputy General Manager made a presentation titled, ‘New Generation Concrete for Tall Structures with PCE’s and beyond’.“Chembond’s construction chemicals have been in use in some of the most prestigious projects in India. We are proud to be associated with the Indian Concrete Institute as associate sponsor of Cemcon 2011, said Nirmal Shah, Joint Managing Director.“We welcomed all visitors and attendees to interact and discuss their technical challenges with us so that we may be able to come up with a solution to the same, said Kanitkar. “On display in our stall was a large part of our range of construction solutions encompassing areas like waterproofing, sealants, concrete and mortar admixtures, tile fixing adhesives, tile joint fillers and engineering grouts, said Mangesh Patil, Head Infrastructure Business. repairMeanwhile, concretes based on hydraulic binders such as Ordinary Portland cement have a common tendency to . injection using either Epoxy Resin or Polyurethane resin based grouts, is one of the most efficient and effective techniques used; separately discussed by Kanitkar, an expert in the field. Epoxy resins are used for structural repair while polyurethane resins are used in situations where movement is expected or water leakages have to be stopped quickly. Sometimes a combination of both materials may also be used. While formulating and recommending both materials, one must bear in mind that both are sensitive to water. Typically, epoxy resins have difficulty in setting and developing the desired strength in the presence of water. Polyurethane resins on the other hand are available in one, two or three pack systems. One pack resins generally foam in the presence of water, thus effecting quick stoppage of flowing water through s. Two and three pack systems offer either a flexible sealing solution or foam like single pack resins. The foam generated by such systems, is more flexible than the single pack resin.Structural repairDepending on the specific requirements of the job, repair by epoxy injection can restore structural integrity and reduce moisture penetration through concrete s 0.002 in. (0.05 mm) in width and greater. First, s must be cleaned from foreign matter before injection. Material selection is critical. Sometimes initial Polyurethane injection or use of cement based water plugs may be necessary to stop the flow of water. Injection equipment comprises air assisted guns, hand actuated delivery systems, and spring or balloon actuated capsules.The procedure begins with the installation of injection ports at proper spacing generally at 40 mm in centre. s are then sealed through its length with suitable sealing material. Injection is carried out after the cap seal is set. After the injection is complete, the ports are removed. The cap seal may be completely removed using suitable procedure such as grinding or left in place, if it is not objectionable. Non-structural repairIf the does not compromise the structural integrity of the structure, injection with polyurethane grouts or other nonstructural materials may be a more suitable choice to fill the . Mainly, two types of polyurethane based injection resins are used. One system is used for sealing dry or damp s and the other to stop the flowing water. Both single and two or three component systems may be used for generating foam. The foaming action is very quick. The dual component and three component resins may require multi component guns depending on the reaction time. Mixing and delivery of mixed materials must be well controlled. The repair procedure mostly remains the same like the one used for epoxy injection. Health and safetyBoth epoxies and polyurethanes are hazardous materials and must be handled with care. Jobsite safety practices should include, but not necessarily be limited to, the following:lKeeping a copy of Material Safety Data Sheets (MSDS) on site.lWearing protective clothing and protective eyewear where required.lWearing rubber gloves or barrier creams for hand protection.lHaving eye wash facilities available.lWearing respirators where needed.lProviding ventilation of closed spaces.lSecured storage of hazardous materials.lHaving necessary cleaning materials on hand andlNotifying occupants of pending repair procedures.