Mechanical performance and capillary water absorption of sewage sludge ash concrete (SSAC)

Municipal incinerator bottom ash (MIBA) and sewage sludge ash (SSA) are secondary wastes produced from municipal incinerators. Landfills, disposal at sea, and agricultural use have been the major outlets for these secondary wastes. As global emphasis on sustainability arises, many have called for an increasing reuse of waste materials as valuable resources. In this study, MIBA and SSA were mixed with clay for ceramic tile manufacturing in this study. Raw materials firstly went through TCLP (Toxicity Characteristic Leaching Procedure) to ensure their feasibility for reuse. From scanning electron microscopy (SEM), clay’s smooth surface was contrasted with the porous surface of MIBA and SSA, which led to a higher water requirement for the mixing. Specimens with five MIBA mix percentages of 0%, 5%, 10%, 15%, and 20% (wt) and three SSA mix percentages of 0%, 10%, and 20% (wt) were made to compare how the two waste materials affected the quality of the final product and to what extent. Shrinkage tests showed that MIBA and SSA contributed oppositely to tile shrinkage, as more MIBA reduced tile shrinkage, while more SSA encouraged tile shrinkage. However, as the kiln temperature reached 1150 °C, the SiO2-rich SSA adversely reduced the shrinkage due to the glass phase that formed to expand the tile instead. Both MIBA and SSA increased water tile absorption and reduced its bending strength and wear resistance. Increasing the kiln temperature could effectively improve the water absorption, bending strength, and wear resistance of high MIBA and SSA mixes, as SEM showed a more compact structure at higher temperatures. However, when the temperature reached 1100 °C, more pores appeared and seemingly exhausted the benefit brought by the higher temperature. Complex interactions between kiln temperature and MIBA/SSA mix percentage bring unpredictable performance of tile shrinkage, bending strength, and water absorption, which makes it very challenging to create a sample meeting all the specification requirements. We conclude that a mix with up to 20% of SSA and 5% of MIBA could result in quality tiles meeting the requirements for interior or exterior flooring applications when the kiln temperature is carefully controlled.

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Mechanical Performance of Concrete with Partial Replacement of Sand by Sewage Sludge Ash from Incineration

Materials Science Forum ◽

10.4028/www.scientific.net/msf.730-732.462 ◽

2012 ◽

Vol 730-732 ◽

pp. 462-467 ◽

Cited By ~ 9

Author(s):

A. Jamshidi ◽

M. Jamshidi ◽

N. Mehrdadi ◽

A. Shasavandi ◽

F. Pacheco-Torgal

Keyword(s):

Sewage Sludge ◽

Environmental Problem ◽

Mechanical Performance ◽

Waste Water Treatment ◽

Xrd Analysis ◽

Mechanical Tests ◽

Partial Replacement ◽

Sewage Sludge Ash ◽

Sludge Ash ◽

Ash Disposal

The production of sewage sludge from waste water treatment plants is increasing all over the world. Disposal of sewage sludge ash is a serious environmental problem. If we think of the areas needed for sludge ash disposal, we clearly understand the importance of reusing sewage sludge ash in concrete. This paper presents results related to the replacement of sand by sewage sludge ash. The sludge was characterized for chemical composition (XRF analysis), crystalline phases (XRD analysis) and pozzolanic activity. The effects of incineration on crystal phases of dry sludge were investigated. Two (W/C) ratios (0.55 and 0.45) and three sludge percentages (5%, 10% and 20%) by cement mass were used. The mechanical performance of SSAC at different curing ages (3, 7, 28 and 90 days) was assessed by means of mechanical tests. Results show that sewage sludge ash leads to a reduction in density and mechanical strength. Results also show that concrete with 20% of sewage sludge ash and W/C=0.45 has a 28 day compressive strength of almost 30MPa.

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Compressive Strength and Water Absorption of Sewage Sludge Ash (SSA) Mortar

InCIEC 2015 ◽

10.1007/978-981-10-0155-0_19 ◽

2016 ◽

pp. 199-207

Author(s):

M. Y. Nurul Nazierah ◽

K. Kartini ◽

M. S. Hamidah ◽

T. Nuraini

Keyword(s):

Compressive Strength ◽

Sewage Sludge ◽

Water Absorption ◽

Sewage Sludge Ash ◽

Sludge Ash

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Concrete for Precast Blocks: Binary and Ternary Combination of Sewage Sludge Ash with Diverse Mineral Residue

Materials ◽

10.3390/ma13204634 ◽

2020 ◽

Vol 13 (20) ◽

pp. 4634

Author(s):

Francisco Baeza-Brotons ◽

Jordi Payá ◽

Oscar Galao ◽

Marcos Alberti ◽

Pedro Garcés

Keyword(s):

Sewage Sludge ◽

Portland Cement ◽

Water Absorption ◽

Reference Sample ◽

Ultrasonic Pulse Velocity ◽

Mechanical Tests ◽

Pulse Velocity ◽

Sewage Sludge Ash ◽

Mineral Additions ◽

Sludge Ash

This paper proposes binary and ternary combinations of sewage sludge ash (SSA) with fly ash (FA), marble dust (MD) and rice husk ash (RHA) as partial replacements of Portland cement in concretes with a similar dosage to that used in precast blocks, with very dry consistency. Several physical-mechanical tests were carried out on concrete specimens with curing ages of 28 and 90 days: density, water absorption, capillary water absorption, ultrasonic pulse velocity and compressive strength. The combinations of residues significantly improve the properties of the cementitious systems: 30% replacement of Portland cement provides strength values similar to the reference sample, showing the synergetic effects of the combination of the mineral additions. The significance of this research relies on the combined use of the mineral additions as well as the use of them for the precast block industry. The results show synergies among the additions and even that some of them showed relevant improvements when they are used in combination, performing better than when used individually.

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