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• Features & Benefits
• Technical Characteristics
• Recommendations
• How to Use
• Consumption

Features & Benefits

• Added during mixing to repair mortars from the Mapegrout range (Mapegrout T40, Mapegrout T60, Mapegrout Thixotropic, Mapegrout Hi-Flow, Mapegrout BM, Mapegrout FMR and Mapegrout Easy Flow), to binders, such as Stabilcem and Stabilcem SCC, and to all types of concrete
• Allows products above to expand during the first few days of curing, including during air curing
• This property helps reduce the formation of micro-cracks and also guarantees that the final level of hydraulic shrinkage is extremely low

Technical Characteristics

Mapecure SRA is a special, chloride-free liquid admixture specially developed in MAPEI’s Research & Development laboratories, to reduce final hygrometric shrinkage of mortar, ordinary and self-compacting concrete, to make them less prone to cracking problems. Mapecure SRA works by reducing the surface stresses of the water present in the capillary pores and as a result, the forces which act upon the walls of the pores is greatly reduced. Thanks to this phenomenon, the reduction in shrinkage is clearly visible (Fig. 1).

The best results are obtained when Mapecure SRA is mixed with controlled-shrinkage repair mortars or in combination with concrete which contains Expancrete, in that it allows these systems to expand even further during the first few days of hardening, whether they are damp-cured or air-cured.

When Mapecure SRA and Expancrete (Mapecrete System) are used together, the advantages of each single product combine and are greatly enhanced, to guarantee that the properties of mortar and concrete reach levels which would normally be impossible with traditional cementitious systems.

As a result of this technology and according to the composition of the concrete, the final expansion and shrinkage levels may be programmed to guarantee that the structure acquires higher durability (Fig. 2). According to the doses used, Mapecure SRA reduces the final mechanical strength by 5-6% (Figs. 3 and 4).

Mapecure SRA is compatible with all traditional, naphthalene sulphonate-based super-plasticising admixtures from the Mapefluid range, the new acrylic admixtures from the Dynamon range and with all types of cement according to UNI EN 197/1 Standards.

Mapecure SRA complies with Italian standard UNI 11641:2016 concerning the shrinkage reducing agent.

Recommendations

• Mortar and concrete which contain Mapecure SRA, especially in hot, windy climates, must be cured under damp conditions or protected with an anti-evaporation film, such as Mapecure S or Mapecure E, to avoid rapid evaporation of water due to the high surrounding temperature
• Only add Mapecure SRA to the concrete once all the other components have been added

How to Use

Repair mortar

• Pour the amount of water recommended in the Technical Data Sheet for the product to be used into a concrete mixer
• Start up the concrete mixer and mix the contents for a few minutes
• Add Mapecure SRA at a rate of 0.25-0.5% by weight of the mix
• Continue mixing until a lump-free, homogenous mix is obtained

Concrete

• Add Mapecure SRA to the mix at a rate of 5-8 l/m³ after adding the cement, aggregates and 70% of the mixing water required
• Then add the remaining water and mix until the required consistency is obtained

Consumption

Mortar

• 0.25-0.5% by weight of the mix

Concrete

• 5-8 l/m³