Surface Preparation

All the loose cracked & delaminated concrete shall be removed by chipping or other mechanical means. The extremities of repair locations shall be cut behind the reinforcement or saw cut to a depth of at least 10 mm to avoid feather edging. The areas to be repaired shall be profiled to get rectangular or square shape with an inward tapering edges. Clean the surface to remove all traces of dust, oil, paint, grease, algae etc. Oil & grease deposits can be removed by steam cleaning, detergent scrubbing or by using degreaser. The area cleaned shall be washed with water to remove all traces of dust, loose particles etc.

Surface preparation of steel

Steel reinforcement encountered during repair shall also be cleaned to remove all traces of rust, corrosion scales etc. using wire brush / emery paper. If sand blasting is allowed it can be resorted to. Extra steel if necessary shall be provided. If chlorides are anticipated then high pressure washing with water shall be carried out.

Reinforcement Priming

The exposed and cleaned reinforcing bar shall be provided with anti corrosive coat of DR.Fixit Zinc Epoxy Primer such that the coated film will have a dft of 40 microns. The film shall be continuous especially in the regions where pitting, imperfections etc. are presents on the surface of the bars. It is important that the rear portion of the bars should not be left over without coating. A second coat if needed may be provided to achieve a uniform and continuous film

Priming Concrete Surface / Bonding agent

The exposed concrete surfaces shall be cleaned to remove any traces of dust, loose concrete etc. with the help of compressed air. The substrate shall be thoroughly washed with water jet to remove any traces of contamination. The surface shall be primed with Dr.Fixit Epoxy Bonding Agent an epoxy based bonding agent before applying repair mortar

Mixing of Ready-To-Use Polymer Modified Mortar Dr.Fixit Polymer Mortar PX

Care should be taken to ensure that Dr.Fixit Polymer Mortar PX  is thoroughly mixed. A forced action mixer is essential. Mixing in a suitable sized drum using an approved spiral paddle in a slow speed (500 rpm) heavy duty drill is acceptable for the occasional one bag mix. Free fall mixers must not be used.

For normal application use 3.25 - 3.50 liters of drinking quality water per 25 Kg bag of Dr.Fixit Polymer Mortar PX. Always add polymer into water first & then add entire quantity of powder while mixing simultaneously. Mix for 2 min until homogeneous material results. Depending on the ambient temperature & the desired consistency, the amount of water required may vary slightly but should not exceed 3.5 liters per 25 kg bag of Dr.Fixit Polymer Mortar PX under any circumstances.

Exposed steel reinforcing bars should be firmly secured to avoid movement during the application process, as this will effect mortar compaction, build & bond. Apply the mixed Dr.Fixit Polymer Mortar PX to the prepared substrate by gloved hand or trowel. Thoroughly compact the mortar on to the primed substrate, when the bonding coat is still tacky & around the exposed reinforcement. Dr.Fixit Polymer Mortar PX can be applied to a maximum thickness of 20 mm in single application. Subsequent applications can be done to build up the required thickness, up to 50 mm maximum. It is essential to apply bonding agent every time before applying Dr.Fixit Polymer Mortar PX If sagging occurs during application to vertical surfaces the Dr.Fixit Polymer Mortar PX should be completely removed & reapplied at a reduced thickness on the correctly re-primed substrate. Dr.Fixit Polymer Mortar PX should not be applied as a render on large areas.

Finishing

Finish Dr.Fixit Polymer Mortar PX by striking off excess material with a straight edge & close with wooden or plastic floats. Damp sponge may be used to achieve the desired surface texture. The completed surface should not be over worked.

Curing

Dr.Fixit Polymer Mortar PX should be cured immediately after finishing in accordance with good concrete practices. The use of Pidicrete MPB  sprayed on the surface of the finished Dr.Fixit Polymer Mortar PX  in a continuous film is recommended. Large areas should be cured as toweling progresses without waiting for completion of the entire area. In fast drying conditions supplementary curing with polythene sheeting taped down at the edges must be used.