Sakrete Concrete Mix
SAKRETE Concrete Mix is a pre-blended concrete material. It is designed for new concrete construction projects, concrete overlays, and repairs where a thickness 5 cm (2”) or more is required. Open to foot traffic in approximately 24 hours. Meets or exceeds ASTM C 387 strength requirements.
- General purpose
- Ready to use; just add water.
|Hole Diameter||# of Bags|
|15 cm (6”)||1.5|
|20 cm (8”)||3|
|25 cm (10”)||4.5|
|30 cm (12”)||6.5|
|Post Size: 10 cm (4") X 10 cm (4”)|
|Hole Diameter: 20 cm (8”)|
||# of Bags|
|45 cm (18”)||1|
|60 cm (24”)||1.25|
|90 cm (36”)||1.75|
|120 cm (48”)||2|
|30 cm (12”)||70 cm (24”)||90 cm (36”)||120 cm (48”)|
|30 cm (12”)||0.7||1.3||2.0||2.7|
|70 cm (24”)||1.3||2.7||4.0||5.3|
|90 cm (36”)||2.0||4,0||6.0||8.0|
|120 cm (48”)||2.7||5.3||8.0||10.7|
|150 cm (60”)||3.3||6,7||10.0||13.3|
30 KG (66 lb) yields approximately 0.014 m³ (1/2 ft³).
Curing means maintaining proper moisture and temperature. Allow newly placed material to set until the surface is hard to the touch. SAKRETE Concrete Mix will set in approximately 6 hours. Keep material damp or cover with plastic to prevent evaporation of mix water for at least three (3) days. Protect from freezing for at least 24 hours. New concrete can be open to foot traffic in 24 hours.
- Planning: Position layout stakes aligned with the project borders. Place corner stakes 300 mm (12 in) outside the finished slab area. Join stakes together with string, the corners should overlap. String lines will show the planned layout and provide the height form boards are to be set at.
- Excavating: The total depth of the excavation, approximately 130 mm (5 in) to 150 mm (6 in), should be determined by allowing for 2 inches (5 cm) minimum of compacted crushed stone under 80 mm (3 in) to 100 mm (4 in) of concrete. Excavate 150 mm (6 in) beyond string lines to allow room for forms. Spread crushed stone evenly throughout the excavation and compact well using a portable vibrator, roller, or hand tamper.
- Forming: Using straight 50 mm (2 in) x 100 mm (4 in) lumber, cut forms to length, then position so inside edges are below the string line. Drive pointed 50 mm (2 in) x 100 mm (4 in) stakes into ground at 1 m (3 ft) spacing to support forms. Screw together all forms, braces, and corners from outside the work area. NOTE: Adjust forms before securing to direct rainwater run-off. Slope approximately 3 mm (1/8 in) per 305 mm (1 ft).
- Curving: Create curves by attaching 30 mm (1/8 in) hardboard to inside corners of forms. Drive support stakes behind the curved form. Place expansion joint board against adjoining surfaces to allow independent movement. Treat the inside of the forms with a commercial release-agent or vegetable oil prior to pouring.
- Placing: After mixing the concrete, place and consolidate inside the forms, slightly overfilling and roughly levelled. Work a pointed trowel along inside edges of the forms removing trapped air pockets. Tap the forms with a hammer for smoother sides. NOTE: Mixing, placing, and finishing should be timed to make sure concrete does not harden before finishing.
- Levelling: Level concrete, moving a straight-edged board overlapping the forms in a sawing motion across concrete removing any excess and filling low areas. Then float the concrete smooth using a wood, magnesium, or aluminum float trowel. Stop floating when bleed water accumulates on the surface.
- Finishing: After bleed water evaporates, finish as desired. It is recommended, especially for air-entrained concrete (i.e., SAKRETE PSI 6000), to use a wood, magnesium, or aluminum float trowel for a smooth surface. For a textured surface use a broom or brush. Use an edger tool to finish edges. NOTE: Finishing cementitious materials too early, or overworking the material, can cause dusting, cracking, scaling, and a weak surface
- Jointing: Stress control joints are placed to control where slabs crack, along a predetermined path. Use either a hand jointer while the mix is soft or saw cut 6 to 18 hours after hardening. The joint should be 1/5 of the full thickness of the slab and every 2,4 m (8 ft) in both directions. Adjust down for appearances (centring).
- Curing: See below.
- Excavation: Dig hole with an auger or shovel to required depth (hole should extend below the frost line). Allow 50 mm (2 in) clearance on each side of post. A typical 100 mm (4 in) x 100 mm (4 in) post will require a 200 mm (8 in) diameter.
- Placing: Position the post in the hole and pour in mixed concrete. Align post using a level and check the vertical position. Cross-brace post for support while mix is wet. Allow to set for 24 hours then remove bracing and top with soil.
- Curing: See below.
- Surface Preparation: Surfaces to be repaired must be sound and clean. Remove all delaminated or unsound concrete by chipping with a hammer and chisel or using a stiff wire brush. Clean the area to be repaired with potable water, leaving the concrete saturated but free of standing water. Some very porous concretes may require several applications of water to ensure complete saturation. For best results, apply SAKRETE Concrete Adhesive to the existing substrate before pouring.
- Placing: After mixing the concrete, place and consolidate inside the repair area. Level concrete by moving a straight-edged board in a sawing motion across concrete removing any excess and filling low areas. Allow freshly placed concrete to set or wait until the surface bleed water evaporates before finishing. Time will vary with weather conditions.
- Finishing: After bleed water evaporates, finish as desired. It is recommended, especially for air-entrained concrete (i.e., SAKRETE PSI 6000), to use a wood, magnesium, or aluminum float trowel for a smooth surface. For a textured surface, use a broom or brush. If the repair overlay is placed over an existing concrete joint or break, it is important to tool a joint into the soft mix over the existing joint or break. Use a jointer tool to form a joint half the depth of the repair. NOTE: Finishing cementitious materials too early, or overworking the materials can cause dusting, cracking, scaling, and a weak surface.
- Curing: See below.
Empty contents of the bag into mortar box, wheelbarrow, or mechanical mixer. When mixing by hand, form a crater for adding water. Add approximately 2.7 L (2.85 qt) of clean water per 30 KG (66 lb) bag or enough to achieve a workable mix. Avoid a soupy mix. Excess water reduces strength and durability and can cause cracking. In cold weather, use warm water to accelerate the set. In hot weather, use cold water to slow the set.
Add approximately 2.7 L (2.85 qt) of clean water per 30 KG (66 lb) bag or enough to achieve a workable mix.
Mix and substrate temperatures should be maintained between +5 °C and +30 °C (40 °F and 86 °F) for at least 24 hours prior to and 48 hours after. For temperatures below +5 °C (40 °F) refer to SAKRETE Fast Set.
The SAKRETE Concrete Mix is designed for new concrete construction projects, concrete overlays, and repairs where a thickness 50 mm (2 in) or more is required.