Conextra- M

Description

Uses

• General repair and renovation of decayed, defective or damaged concrete structures like beams, columns, walls and honey combed concrete where access is required and compaction is not available.
• Jacketing of RCC columns, strengthening of vertical members.

Advantages
• Can be pumped or poured into restricted locations.
• Flowable mortar eliminates honey combination.
• Develops high initial and ultimate final strength.
• Gaseous expansion system compenstates for shrinking and settles in the plastic state.
• Excellent resistance to moisture Ingress.
• Can be applied at 100 mm thick at one stroke.
• Self compacting with guaranteed performance.
• Easy to use by adding water on site.
• Contains no chloride hence there is no reinforcement corrosion.

Expansion Characteristics
An initial expansion of about 1% when measured according to ASTM C 827 overcomes plastic settlement in the unset material. Expansion in hardened state when measured according to ASTM C 1090-88 compensates for drying shrinkage. Pressure to restrain plastic.

Expansion
Approximately 0.004 N/mm²

Standards
CONEXTRA – M is tested using the relevant section of: ASTM C – 1107 Grade C

BS – 1881
BS – 4550
CRDC – 821 – 82 A
BS – 6319

Yield
Approx 13.0 liter / 25 kg bag. actual yield depends on the consistency required and the site requirement.

Packaging
25 kg in moisture-resistant bags.

Storage and Shelf life
6 months from manufacture in original unopened bags if stored in dry conditions.

Technical Service
Conextra – M has established itself in various fields on the basis of its dependable technical service. For this purpose we maintain a well equipped laboratory for reserch & quality assurance of all products. Our experienced personnel are always on call and would always be available for product demonstrations and product performance monitoring.

Safety Precautions
CONEXTRA – M is a cementitious alkaline product. Care should be taken to avoid contact with eyes, skin, mouth and food stuff. Any splashes on the human body must be washed with plenty of water.

Technical Information

Nature	Cementitious grey powder
Flexural Strength	>5 MPa at 28 days ASTM C 580
Chloride Content	Nill
Depth of Carbonation	Nill
Compressive Strength	At 0.16 w/p ratio @ 30⁰C ASTM C 109

Age (days)	Compressive Strength Mpa
1	20
3	30
7	40
28	50

Wet Density	BS 1881 – 2250 kg/m³
Flexural Strength	@ 28 days 25⁰C 10N/mm²
Setting Time	BS 4550 at 20⁰C and 0.16 water to powder ratio (flowable consistency)
Initial Set	6 hours 00 minutes
Final Set	8 hours 15 minutes
Alkali Content	The presence of non-alkali reactive aggregates ensures its resistance to future expansive reactions and deterioration.
Bond Strength	The typical shear bond strength when tested as per BS-6319 at water powder ratio of 0.16 at 20C without any bonding agent is 68 N/mm² at 28 days.

How to Use

Expose the sound base of defective concrete surfaces. For better adhesion, roughen the prepared surface.
Several hours in advance, water the surface well, Excess water should be removed before application of fresh concrete. The formwork should include drainage outlets for pre-soaking and allow for air venting.
There should be access points to pour or pump in CONEXTRA-M
Mix CONEXTRA-M in a concrete mixture to get a homogenous mix and pour into the formwork.
Allow it to cure for 24 hours.