Repair and retrofitting of existing structures have become a major part of the construction activity in large part of India wherein structures are damaged by environmental effects which include corrosion of steel, variations in temperature, freeze–thaw cycles and exposure to ultra-violet radiation. There are always cases of construction-related and design-related deficiencies that need correction. Many structures, on the other hand, need strengthening because the allowable loads have increased, or new codes have made the structures substandard. This last case applies mostly for seismic regions, where new standards are more comprehensive than the old ones.
There are various methods to repair and retrofitting of the structure which included Polymer Modified Mortar, carbon fiber wrapping, jacketing with Micro concrete (which is non-shrinking or shrinkage compensative). The most common and cost effective method is jacketing with micro concrete where numerous manufacturers in India are producing dry powder based micro concrete, in which water has to be mixed very precisely at site, as per conditions and consultant’s specifications 10mm down aggregates is added at site only.
Site mixing of dry mix micro concrete is a challenge faced by repair contractors and client as it requires skilled labour and high level of supervision during mixing and at the same time execution is very slow because of all these site activities.
To overcome all these challenges in dry micro concrete, Nuvoco developed an innovative product which is non-shrinking, ready to use Instamix Microne for repair and retrofitting of structures.
Having grown hugely popular since its launch, wet-ready-to-use Instamix Microne is the result of incredible disruptive innovation in repair segment, which is conventionally dominated by dry mix products.
Taking site repair elements into consideration, the aggregates used vary in size from 4.75mm to 10mm. One of the biggest reasons for its popularity is that it is a non-shrink product which guarantees excellent plastic and hardened properties. It is extremely durable compared to the dry mix products available in the same range. Being a free flowing mix, it can be used to fill all kinds of difficult to reach areas and boasts of 30 % to 40% more chloride resistance which makes it ideal for all kinds of aggressive environments. Instamix Microne also offers 50% more adhesion strength compared to conventional products and is available in grades of M40, M60, and M80, with a working life of five hours after reaching the site.
Microne Technical data*
Compressive Strength (N/mm²)*
|
Day / Grade |
M-40 |
M-50 |
M-60 |
M-70 |
M-80 |
|
1 Day |
≥10 |
≥12 |
≥15 |
≥18 |
≥20 |
|
3 Day |
≥20 |
≥25 |
≥30 |
≥35 |
≥40 |
|
7 Day |
≥30 |
≥35 |
≥40 |
≥45 |
≥60 |
|
28 Day |
≥40 |
≥50 |
≥60 |
≥70 |
≥80 |
Water Permeability:
(As per DIN 1048 test method)
|
M-40 |
M-50 |
M-60 |
M-70 |
M-80 |
|
<7.5mm |
<5mm |
<5mm |
<2.5mm |
<2.5mm |
Rapid Chloride Permeability
(As per ASTM C1202)
|
|
M-40/ M-50 |
M-60/ M-70 |
M-80 |
|
28D |
1750-2000 |
1500-1750 |
1250-1500 |
|
56D |
1000-1250 |
750-1000 |
500-750 |
*These properties may vary depends on available local raw materials (Cement, Sand, Aggregates etc)
Typical application -
• Extensive repair of beam, column, floor or other structural elements.
• Jacketing of beam, column and other structural elements for strengthening.
• Retrofitting of beam & columns
Features and Benefits
|
It is wet pre-mix, no further addition of water required at site. Results in quality control and also save labour cost. |
Custom made: No need to add the aggregates at site, quality control |
|
Shrinkage Compensated |
Low chloride permeability |
|
Fast and easy placing. |
Excellent bond with mother surface |
|
Normal curing |
Low water permeability: Durable structure. |
|
High durability |
No need to maintain stock at site. |
@EPC World Media
