Effect of Partial Replacement of Stone Dust (SD) With River Sand (RS) On the Mechanical Properties of Interlocking Tiles

Interlocking tiles are masonry units designed to lock together or fit-in along their edges without the need to use mortar for binding the units. Thus, by removing the requirement for mortar in binding the masonry units, interlocking tiles not only offer economy in designs but also maintain environmental sustainability. It is one of the most popular pavements for footpaths, outdoor flooring and landscaping techniques in modern times. The normal interlocking tiles in Nigeria are produced with cement as the binder, stone dust as the fine aggregate and water for hydration. But stone dust is not readily available in every place since it is found in quarries usually located near rock deposits which again cannot be found everywhere. River sand however is much easier to get due to geological activities such weathering, deposition, and transportation. Consequently, this study sorts to understand the behaviour of interlocking tiles produced with the blending of stone dust and river sand, as a way of making such vital flooring masonry units available in places with less availability of stone dust. Two mix ratios were chosen for the study; 1:3 and 1:6 with a water cement ratio of 0.45. The river sand substitution levels adopted were; 0%, 10%, 20%, 30%, 40%, and 50% as a percentage of total dry weight of stone dust in the mix. Results showed that interlocking tiles have better durability performance when the two aggregate materials; stone dust and river sand, are blended together, than when they are used separately in the production of interlocking tile. It was observed in from the study, from both durability and compressive strength point of view, that the 50% SD + 50% RS outperformed the other replacement levels considered, and thus, is adjudged the optimum blending ratio for interlocking tiles. It was also noted that the 1:3 mix ratio performed better than 1:6 mix ratio both in durability and in compressive strength.