Effect of Partial Replacement of Sand With Quarry Dust on the Structural Characteristics of Sandcrete Blocks
This work investigated the effect of partial replacement of sand with quarry dust on the compressive strength, flexural strength, split tensile strength and water absorption of sandcrete blocks. River sand was replaced with quarry dust at percentages ranging from 0 to 40 at cement/combined aggregate ratio of 1: 6. The blocks were moulded using a Rosa Commetta block laying machine and were tested after curing by water sprinkling for 28 days. The results showed that the inclusion of quarry dust improved the properties, with the highest improvement being at 40% replacement for all the properties. The compressive strength, flexural strength and split tensile strength increased by 27, 38 and 19% respectively at 40% replacement.The compressive strength and water absorption of the blocks also met the minimum Nigerian Industrial Standard’s requirement of 3.45N/mm-2 and 12% for vibrated blocks respectively. The results also showed that blocks produced with quarry dust as the sole aggregate have lower qualities than sandcrete blocks of the same mix. It is recommended that partial replacement of sand with quarry dust in sandcrete block production be encouraged as it reduces the excessive demand for river sand and its attendant problems while providing a useful means of utilizing the excess quarry dust produced which, if left to accumulate in large quantities, constitute great environmental hazard.