Description

High Strength, shrinkage controlled, polymer modified, fluid microconcrete for structural repairs of all types

Uses

Renderoc LAXtra Plus is suitable for mass infill to structural repairs in all types of loadbearing situation. Typical applications would include, but not be limited to, the following :

• Repairs to columns suffering from major loss of section

• Soffit repairs where heavy loadbearing is required

• Repairs to restricted access areas, where use of hand applied mortars would prove impractical
• Repairs requiring high fluidity g. heavily congested steel or repairs into re-entrant angles/concealed voids
• Any repairs requiring significant levels of loadbearing

Advantages

Renderoc LAXtra Plus features Dimensional Stability Technology – a new materials technology which controls the rate of drying shrinkage such that, when used correctly :

1. the dimensions of the repair remain stable; and thus

1. eliminating failure, due to shrinkage cracking. This in turn leads to a series of associated benefits :

• Cost effective – shrinkage control enables repairs to be completed ‘right first time’
• Enhanced durability – works in tandem with extremely low permeability to prolong effective working life
• Compatibility – aligns performance closer than ever before, to that of host concrete
• User friendly – specifically developed to provide an easy- to-apply product, suitable for local conditions
• Definable performance – positive benefits are easily demonstrated via a single, simple measurement

Description

Renderoc LAXtra Plus is supplied as a ready to use blend of dry powders and selected aggregates, which requires only the addition of clean water to produce a highly consistent, fluid microconcrete suitable for all load-bearing situations.

Properties

The following typical results were obtained at a water:powder ratio of 0.135

Test method                                        Typical result Drying shrinkage to ASTM C157-93

7 days                      :< 300 microstrain

28 days                    :< 500 microstrain

Flexural strength              :> 9 N/mm2 at 28 days

(BS 6319 Pt.3)                                                                                 

Compressive strength    :> 45 N/mm2 at 3 days

(BS 1881 Pt.1161)               > 56 N/mm2 at 7 days

> 70 N/mm2 at 28 days

Water absorption              :< 2%

(BS 1881 Pt. 122)                                                                           

Note1:      100mm cubes, air cured @ 220C ± 1°C

Design criteria

Dimensional Stability Technology is a major step forward in the general compatibility of repair mortar systems with the host concrete, and the control of shrinkage in particular.

Attention to the basic design criteria given below should ensure that the full benefits of this technology are gained in use :

• Renderoc LAXtra Plus is designed for large volume repairs, typically in excess of 30 mm deep. The product can be applied in sections generally between 30 and 200 mm thick, greater thicknesses may be achievable, depending upon repair configuration and location together with the volume of reinforcing steel.

Consult the local Fosroc office for more information.

• In situations where a substrate/repair barrier is required, or enhanced bond strength/working time is required, or where the substrate is likely to be damp (e.g. seawalls, quays etc.), Nitobond EP epoxy bonding agent should be
• Water addition = 375ltrs / 25kg bag Under no circumstances should part bags be used or additional water be employed. Either of these two actions will adversely affect material performance, automatically invalidating Fosroc’s standard product guarantee.

Fosroc Renderoc LAXtra Plus

Galvanic Protection of repairs

It is likely that, steel reinforcement in the area around a patch repair, particularly in a chloride contaminated environment, will typically corrode after the repairs are carried out, referred to as the incipient anode or Halo effect.

Galvashield XP*† (eXtra Protection) anodes can be incorporated into patch repairs to galvanically protect steel reinforcement against corrosion in the adjacent concrete and may also be used in new construction to provide Cathodic Prevention. Galvashield XP are zinc based anodes encased in a highly alkaline mortar which maintains the surface of the zinc in an active state. Galvanic systems are self regulating and demand based and will start working only when corrosion of steel begins. Refer to product datasheet for further details.

Instructions for use

Renderoc LAXtra Plus should be mixed and applied in strict accordance with the Product Method Statement, a copy of which may be obtained from your nearest Fosroc office.

Estimating

Supply

Renderoc LAXtra Plus        :           25kg bags

Yield

Renderoc LAXtra Plus        :           12.25 ltrs per 25kg bag

Limitations

• Renderoc LAXtra Plus should not be used when the ambient temperature is below 5°C and falling.
• Renderoc LAXtra Plus should not be part mixed, nor part bags
• Renderoc LAXtra Plus should not be exposed to running water either during application or prior to final set.
• Water ponding is not recommended for

Storage

Shelf life

Renderoc LAXtra Plus has a shelf life of 12 months if kept in a dry environment, in its original packing. If stored in conditions of high temperature and/or humidity, the shelf life may be reduced to as little as 4 months.

Standards compliance

Renderoc LAXtra Plus repair microconcrete system complies with the following international standards :

ASTM C157-93 :      Test for drying shrinkage BS 1881 Pt. 122 :           Water absorption

Precautions

Health and safety

Renderoc LAXtra Plus contains cement powders which, when mixed with water or upon becoming damp, release alkalis which can be harmful to the skin.

During use, avoid inhalation of the dust and contact with the skin or eyes. Wear suitable protective clothing – eye protection, gloves and respiratory equipment (particularly in confined spaces).

The use of barrier creams to provide additional skin protection is also advised. In case of contact with the skin, rinse with plenty of clean water, then cleanse thoroughly with soap and water.

In case of contact with eyes, rinse immediately with plenty of clean water and seek medical advice. If swallowed seek medical attention immediately – do not induce vomiting.

Fire

Renderoc LAXtra Plus, is non-flammable and thus presents no fire hazard.

For further information, please refer to the Product Material Safety Data Sheet for Renderoc LAXtra Plus.