The Effect of Periwinkle Shell Ash Mixed with Cement on Water Absorption and Shrinkage of Lateritic Block

The aim of the study is to examine the effect of periwinkle shell ash (PSA) blended with cement on the water absorption and shrinkage of lateritic blocks. The objectives that would help achieve the stated aim are to investigate the water absorption and shrinkage properties of lateritic blocks blended with periwinkle shell ash/cement. The following methods were used during the research: sedimentation test, standard proctor test, Atterberg’s limit test, smell and Nibble tests. Specific gravity of PSA, bulk density and porosity of PSA were carried out. 5 % of the cement and percentage replacement levels of 0 %, 10 %, 20 %, 30 %, 40 % and 50 % of cement with PSA were used for block production. 21 cm × 10 cm × 10 cm blocks were moulded, cured and subjected to water absorption and shrinkage tests. Data were collected and analysed using graphs, correlation and regression analyses. Result shows that percentage water absorption for replacement levels 0 %, 10 %, 20 %, 30 % were 12.08 %, 16.38 %, 18.21 %, 19.95 %. Again, from 0 % replacement to 30 % replacement of cement with PSA, the linear shrinkage increased from 1.5 mm to 2.8 mm. It implies that up to 30 %, the maximum crack the block could form is 2.8 mm, whereas the maximum allowable crack width for walling materials is 3.0 mm. Therefore, percentage replacement of up to 30 % is recommended for use in lateritic block.