Engineering Properties of Paving stones made with Bamboo ash as a Partial Replacement for Cement

Abstract

Abstract Agricultural and industrial wastes are recently being considered for recycling and reuse as likely replacements for cement in the production of concrete and paving stone. Bamboo ash was evaluated as a partial replacement for cement for the production of paving stones with the intent of reducing the carbon-di-oxide emission from cement; and also to enhance environment friendliness. Paving stone is used worldwide for road paving, external works of buildings and ancillary works of embankments and drains. This study investigated the effects of replacing 5, 10 and 15% cement with bamboo ash on the compressive strength of paving stone in a mix proportion of 1:1.38:2.73 and water-cement ratio of 0.4 while the paving stones were cured for 3, 7 and 28 days, respectively. Chemical composition, setting time and standard consistency tests were done on cement; specific gravity, moisture content and sieve analysis tests were performed on aggregates while slump, bulk density and compressive strength tests were conducted on the paving stone samples. Cement recorded a 25% standard consistency; with initial setting time of 23 minutes and final setting time of 276 minutes. Cement had 61.8% Calcium Oxide (CaO) and 21.2% Silicon Dioxide (SiO2) as its major oxide constituents while bamboo ash had 52.49% Silicon Dioxide (SiO2), 14.91% Calcium Oxide (CaO) and 12.71% Aluminium Oxide (Al2O3) as its major oxide constituents. The sand had specific gravity (SG) of 2.55 while the granite had SG of 2.73. The marginal reduction of the compressive strength of the modified bamboo ash paving stones from those of the plain paving stones at 5 % substitution of cement with bamboo ash was achieved.