Effect of Dried Sewage Sludge on Compressive Strength of Concrete

Abstract

Sewage sludge is a waste product generated from the wastewater treatment process at the treatment plant. The amount of sewage sludge produced is increases every year as the population increased. Poor management of sewage sludge will give negative impact to the environment. Replacing cement with sewage sludge ash is more significant to reduce the amount of waste material from sewage treatment plants. In this study, the various percentage of dried sewage sludge (DSS) has been added to replace the cement. Sewage sludge was dried in the oven with 100°C for 24 hours, then sieve through the sieve size 300 µm. Then, DSS was used in the concrete instead of cement with the replacement percentage of 0%, 5%, 10%, and 15% by weight. The compressive strength of concrete cube specimens was investigated after 7 and 28 days of curing. The results showed that the compressive strength of concrete specimens increased with the replacement of cement in concrete with 5 % to 10 % DSS, but the achieved maximum strength still lower compared to the control sample. However, the compressive strength of concrete specimens decreased when the DSS replacement of cement is more than 10 % by weight. The result of XRF test also showed that DSS has good potential to replace cement in concrete.

Recovery of Sewage Sludge in the Cement Industry

“…The sewage sludge ash analyzed in this paper meets the standard conditions to be used as an additive in the cement industry: the content of SO 3 of ash is less than or equal to 4%, the compressive strength at 28 days is greater than or equal to 42.5 MPa, and the initial setting time is greater than or equal to 60 min [15,17].…”

“…Globally, between 2000 and 2018, cement production increased, with an average annual growth rate of 6.2%, reaching 4200 million tons in 2018, compared to 1600 million tons produced in 2000, as seen in Figure 1 [7]. In this paper, sewage sludge ash as raw material for the cement industry has been analyzed [8,[17][18][19]. The ash of sewage sludge comes from the incineration of sewage sludge from wastewater treatment plants, and has a high porosity, and irregular sand-like shape.…”

“…The ash of sewage sludge comes from the incineration of sewage sludge from wastewater treatment plants, and has a high porosity, and irregular sand-like shape. It is a reactive material, which increases the strength of the mortar due to these pozzolanic properties [17,20]. The sewage sludge is dehydrated in the incineration plant up to 30% before burning in a fluidized bed oven at 800-900 • C.…”

“…Global cement production in the years 2000-2018 [7]. According to Figure 2, the quantities of sludge generated by wastewater treatment plants in Romania during 2005-2018 are increasing (from 134 tons of dry matter/year recorded in 2005, to 520 tons of dry matter/year in 2018).In this paper, sewage sludge ash as raw material for the cement industry has been analyzed[8,[17][18][19]. The ash of sewage sludge comes from the incineration of sewage sludge from wastewater treatment plants, and has a high porosity, and irregular sand-like shape.…”

Utilization of textile denim sludge waste in high load-bearing structural applications

“…The compressive strength was reported to be dropped from 17 MPa to 7 MPa with the increasing amount of water-treatment plant sludge addition from 5% to 30% at 1000°C sintering temperature [25]. Another study showed the decrease in compressive strength of concrete when cement was replaced with dried sewage sludge [26]. Incorporating the waste polysilicon sludge in concrete up to 20% replacement level resulted in the increase in compressive strength after 28 days of curing period [27].…”