Crushed stone dust can be effectively used in making cement bricks (also called concrete bricks or masonry blocks) as a partial or full replacement for natural sand. Here’s a detailed guide on its application, benefits, and considerations:
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1. Composition of Cement Bricks with Stone Dust
A typical mix for cement bricks using crushed stone dust includes:
– Cement (OPC 43/53 grade): 10–15%
– Crushed stone dust: 60–75% (replaces fine aggregate/sand)
– Coarse aggregate (6–12mm): 10–20% (optional, for higher strength)
– Water: Adjust for workability (water-cement ratio ~0.4–0.6)
– Admixtures (optional): Plasticizers or fly ash to improve workability/strength.
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2. Benefits of Using Stone Dust
– Cost-effective: Cheaper than river sand in many regions.
– Eco-friendly: Utilizes quarry waste, reducing environmental impact.
– Improved strength: Angular particles enhance interlocking, increasing compressive strength (up to 10–15 MPa for non-load-bearing bricks).
– Reduced shrinkage: Lower water absorption compared to some sands.
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3. Key Considerations
# a. Quality of Stone Dust
– Use well-graded stone dust (0–5mm) with minimal clay/silt content (<3%).
– Avoid excessive fines, which increase water demand and weaken the brick.
# b. Mix Design Optimization
– Conduct trial mixes to adjust cement content and water ratio.
– For load.jpg)
aring bricks, increase cement (up to 15%) or add coarse aggregates.
# c. Curing
– Cure bricks for 7–14 days under moist conditions to prevent cracking and ensure strength gain.
# d. Compaction
– Vibratory compaction improves density and reduces voids in the bricks.
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4. Step-by-Step Manufacturing Process
1. Mix Preparation: Blend cement, stone dust, and water uniformly.
2. Molding: Fill molds manually or using hydraulic/pressure machines.
3. Compaction: Vibrate or press to remove air voids.
4. Demolding: Remove bricks after initial setting (~24 hours).
5. Curing: Water cure for 7+ days before drying/shading.
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