MSWI Bottom Ash Application to Resist Sulfate Attack on Concrete

Abstract

This research provides a strategy for partially replacing cement with municipal solid waste incineration (MSWI) bottom ash (BA) to improve the performance of concrete against sulphate attack. Mortar strength tests were performed firstly to evaluate the hydration activity of the ground BA. Concrete specimens were cured in standard conditions and immersed in a solution that contained 10% sodium sulfate. Then, the compressive strength of these specimens was measured to investigate the mechanical properties and durability of the concrete. Next, the capillary porosity of the concrete was determined from the volume fractions of water lost in specimens. Finally, the transport of the sulphate solution in concrete was analyzed using capillary rise, crystallization rate, and solution absorption tests. The results indicated that BA had a certain hydration activity. The equivalent replacement of cement by BA decreased the compressive strength of the specimens but increased the durability of the concrete. There was an excellent correlation between capillary rise height, sulfate solution absorption amount, crystallization rate, and coarse capillary porosity. The addition of BA can decrease the coarse capillary porosity and further slow the capillary transport and crystallization of sulfate solution in concrete. Overall, the replacement of cement with BA can improve the durability of concrete and actualize the utilization of MSWI residues as a resource.

Effect of Dry–Wet Cycle Periods on Properties of Concrete under Sulfate Attack

“…The aggregate included natural river sand with a fineness modulus of 2.87 and basalt gravel with a continuous gradation of 5-20 mm in particle size. Replacing cement with 20% fly ash had been reported to significantly improve the resistance of concrete to sulfate attack [24][25][26]; thus, concrete with a strength grade of C30 and 20% fly ash were selected in this study. The mixture ratios are shown in Table 2.…”

Municipal solid waste incineration residues recycled for typical construction materials—a review

“…MSWI bottom ash was used partially replacing cement. 87 The equivalent substitution of bottom ash for cement reduced the compressive strength of concrete. The maximum ratio of replacing cement with bottom ash was 15% and this binder was suitable for application in low strength concrete.…”

The Effect of Municipal Solid Waste Incineration Ash on the Properties and Durability of Cement Concrete

“…The results showed that after 28 days of curing, the compressive strength of the specimens was almost 40.0 MPa. The authors [26] replaced cement with 10% and 15% of bottom ash in concrete mixes. The studies show that after 28 days of curing, the compressive strength of the cement pastes with W/C ratio of 0.45 reached 29 MPa and 26 MPa, respectively.…”

“…Dry-cast concrete with 20% cement replaced by bottom ash showed 18% higher strength [25]. Cheng et al [26] found that the optimal ash content in concrete was between 10% and 15%. Within this range, the ash not only improves the durability of concrete, but also ensures that concrete strength meets the design requirements.…”