Study on cement mortar and concrete made with sewage sludge ash

Abstract

This study investigated the feasibility of reusing wastewater sludge ash in construction materials to replace partial materials. Wastewater sludge sampled from thermal power plant was burned into sludge ash at 800°C in the laboratory. The sludge incineration ash has low heavy metal including Pb, Cd, Cr and Cu, so it belongs to general enterprise waste. The chemical composition of sludge incineration ash was summed up in SiO₂, CaO, Fe₂O₃ and MgO. Then the wastewater sludge ash is also found to be a porous material with irregular surface. When the sludge ash was used to replace mortar or concrete cement, its water-adsorption capability will result in the reduction of mortar workability and compressive strength. Cement is being substituted for sludge ash, and 10 percent of sludge ash is more appropriate. Sludge ash is reused to take the place of construction materials and satisfies the requests of standard specification except for higher water absorption.

Growth of spindle‐shaped silver nanoparticles in SDS solutions

“…A typical UV-vis absorption spectrum of as-fabricated silver nanoparticles is given in figure 2. Two bands at λ max =295 nm (weak) and 440 nm (strong) are observed in UV-vis absorption spectrum, which is similar to the results in references [20] and [21]. The peak at 295 nm is due to the formation of various types of silver ions such as Ag 2 + , Ag 3 + , Ag 4 + cluster and small clusters [22,23].…”

Sewage sludge ash characteristics and potential for use in concrete

“…The amorphous content of SSA ranged from 35-75%, which suggests that the material is somewhat reactive and, when ground sufficiently fine, may have potential as a cement component. Table 1 has been prepared to provide analysis of the extensively reported toxic and non-toxic element concentrations of SSA [2,4,12,13,17,28,30,32,34,35,42,44,45,49,55,56,58,[70][71][72][73][74]76,82,83,85,87,97,[100][101][102][103][104]107,108,.…”

“…6 as the percentage change from the control, point to reductions in workability with a like-for-like replacement of cement with SSA [13,21,37,55,62,145,146]. The average rate of decrease in workability calculated is 6% for every 10% SSA and equivalent slump reductions of 12% per 10% SSA have also been determined for concrete mixes [21,27,55,138]. Whilst this data provides an informative benchmark for SSA performance in fresh mortar/ concrete, the specifier should perhaps seek to adjust the mix design to accommodate the characteristics of the material, possibly with the use of water reducing admixtures to achieve satisfactory workability and the results suggest that this is very doable at low SSA contents.…”

Wpływ popiołu z termicznego przekształcania komunalnych osadów ściekowych na wybrane właściwości zawiesin twardniejących

“…In brackets are shown as scatter of results from the average as a coefficient of variation (n in percentages). In addition, table 4 shows the values of brittleness. …”

“…The test results presented in literature [4,7,10,14,20] indicate a very limited suitability of SSTT ash for the construction industry, and particularly for modern concrete technology. Moreover, the high water demand and low pozzolanic activity of this ash preclude its use as an additive in concrete.…”