Sika® Chapdur® BD

Natural mineral aggregates graded and mixed with cement, admixtures and pigments

12 months from date of production if stored as per recommendation.

The product must be stored in original, unopened and undamaged sealed packaging in dry conditions at temperatures between +10°C and +30°C

1.5 ± 0.1 kg/L at +27°C

2.5 to 3.0 mm at dosage of ~ 5.0 kg/m²

+5°C min. / +35°C max.

30% min. / 98% max.

+5°C min. / +35°C max.

The above values are at substrate temperature of +27 °C and dependent upon the concrete reaching its design strength for serviceability and will be affected by changing ambient conditions, particularly temperature and relative humidity. 

For mechanical application with automatic spreader and laser screed, the spreading can start almost immediately after the concrete has been levelled to allow for the hydration of the dry shake. Compaction with the trowel can start as soon as the weight of the power trowels is supported by the concrete. 
For manual application, the dry shake must be spread once the concrete can be stepped on, without leaving a print deeper than 3 - 5 mm.

• The concrete deliveries must be of consistent quality. 
• A concrete slump in the range 75 to 110 mm will normally give best results.
• The slab must be of good quality concrete with a minimum water/cement ratio consistent with the production of a fully compacted slab.
• The compressive strength must be a minimum of 20 N/mm².
• Use of Sikament® or Sika® Viscocrete® super plasticizers is advised to ensure the optimum quality of concrete and where fibers are used, their optimum dispersion within the mix.
• Air Entrained Concrete is not a suitable substrate for the application of dry shake hardeners.

Broad casting of Sika® Chapdur® BD premix 

The concrete slab is ready for the Sika® Chapdur® BD cement coating when a thumb pressed hard onto the surface only leaves a print of about 3-5 mm depth. Sprinkle 60% of Sika® Chapdur® BD onto the screed concrete evenly by hand or with suitable device.

Compaction
Wait until the Sika® Chapdur® BD has been evenly moistened by the water in the concrete, Use a low rpm mechanical trowel, held perfectly flat.
Note : If parts of the surface come loose or if the laitance rises, this means the concrete is still too fresh.

Smoothing
As soon as the plasticity or initial set allows, perform preliminary smoothing with the same machine running at low speed but equipped with metal smoothing blades, set at minimum angle. Sprinkle remaining 40% of Sika® Chapdur® BD onto the screed concrete evenly by hand or with suitable device and 2nd stage of compaction has to done. Any final smoothing required should be performed later with the machine running at high speed.

Joints
Construction joints, expansion joints and floor joints should be saw-cut only after 24 hours. When the slab has hardened, the joints can be filled with the appropriate Sikaflex Sealant in accordance with the floor requirements.

Cure Sika® Chapdur® BD immediately after finishing using clean water. For chemical curing, please consult Sika Technical Service team.
 

Joints:
After finishing operations and completing saw cuts, clean off any residual saw lubricant / slurry without delay. Joints can be filled with Sikaflex® PRO-3WF or any other appropriate Sikaflex® sealant in accordance with the floor design requirements.

To maintain the appearance of the floor after application, Sika® Chapdur® BD must have all spillages removed immediately and must be regularly cleaned using rotary brush, mechanical scrubbers, scrubber dryer, high pressure washer, wash and vacuum techniques, etc., using suitable detergents and waxes.