The research was carried out to investigate and compare the equivalent strength replacement of manually compacted blocks using varying percentage replacement for sand with termitarium silty fine ranging from 0%, 6%, 12%, 18%, 24%, 30%, and 36%. The termitaruim silty clay was collected from a different depth of 5 cm and above in Calabar, Cross River State, Nigeria. A mix ratio of 1: 6: 0.55 was adopted via batching by weighing for the research. 450 x 255 x 150 mm hollow block mold was used in molding the blocks manually. A total of fifty-six (56) blocks samples were molded with different percentage replacement of sand with termitarium silty fine ranging from 0%, 6%, 12%, 18%, 24%, 30%, and 36 %. The blocks were cured manually through spraying of water for 7, 14, 21, and 28 days respectively. The result revealed that at the 28th-day compressive strength test of the block in N/mm2 was 2.07 and the lowest strength of individual block at 28th day’s compressive strength test in N/mm2 was 1.41N/mm2. The result indicates that the termitarium silty fine used as a partial replacement for sand could satisfactorily replace sand up to 10% at 28 days of 2.07 N/mm2 as compressive strength. From the test result conducted on the research material, it indicated that the termitarium silty fine can harmonize a project work effectively and can also be used as subgrade material.

Keywords: Block works, CBR test, manual compaction, Termitarium, Silty fine