Abstract:
Nowadays, there are too many sludges that remain after Water Treatment Plant. It will be better if sludges can be applied. So, there are two main objectives for this research. First, to study the possibility of making the paving blocks mixed with sludge. The another
one is to study the compressive strength of the paving blocks mixed with sludge for comparing with Industrial Standard 827-2531 [1]. In this study, the paving blocks were mixed with sludge 0, 10, 20, 30, 40, 50 and 60 percentage by weight instead of sand and fine stone. Then they were soaked with water 3, 7, 14 and 28 days. Afterwards, they were determined the compressive strength and water absorption value.
The results showed that the suitable ratio to make the paving blocks mixed with sludge is 10 percentage by weight, w/c (water cement ratio) of 0.6, compressive strength value is 352 kg/cm2 and water absorption value is 10 percentage.
However, there are too small amounts of sludges that be used. There fore, these paving blocks were tested for benefits. They can be separated into there formulas
Formula 1 (used for making the paving blocks mixed with sludge standardized by Industrial standard 827-2531) The paving blocks were mixed with 10 percentage of sludge, w/c of 0.6, compressive strength value is 352 kg/cm2 and water absorption value is 10 percentage.
Formula 2 (used for making the moderate strength paving blocks mixed with sludge) The paving blocks were mixed with 30 percentage of sludge, w/c of 0.8, compressive strength value is 170 kg/cm2 and water absorption value is 15 percentage.
Formula 3 (used for making the low strength paving blocks mixed with sludge) The paving blocks were mixed with 50 percentage of sludge, w/c of 1, compressive strength value is 72 kg/cm2 and water absorption value is 26 percentage.
Formula 1 can be used for read surface and general footpath. Formula 2 is better than 3 while both of them can be used for the small bearing road surface and general footpath. It can be concluded that sludges can be used as mixtures in paving blocks. This
benefit can increase the value of sludges but decrease the block price. Moreover, the sludges can be eradicated, while the blocks can be used in many beneficial works.