Municipal solid waste incineration (MSWI) bottom ash-blended cementitious materials: Performance, challenges, and potential solutions
Boyu Chen, Priyadharshini Perumal, Chen Liu, Yun Chen, Cheng Chang, Majda Pavlin, Davor Kvočka, Vilma Ducman, Terο Luukkοnen, Mirja Illikainen, Guang Ye
Abstract
The recycling of municipal solid waste incineration (MSWI) bottom ash as a supplementary cementitious material (SCM) has attracted global attention, driven by the increasing availability of this by-product and the demand for sustainable SCMs to lower CO2 emissions from cement production. Currently, the widespread use of MSWI bottom ash in the cement industry is hindered by the lack of guidelines to regulate material composition, optimize pretreatment processes, and specify mix design requirements. This review compiles and analyzes literature data on mix design, microstructural evolution, fresh properties, mechanical properties, durability, leaching risks, and environmental impacts of MSWI bottom ash-blended cement pastes, mortars, and concretes. The analysis aims to assess the influence of the pretreatment and physicochemical properties of bottom ashFootnote1 on the microstructure and performance of blended cementitious materials.Footnote2 The Ash Impact Strength Index (AISI) is introduced to quantify the effects of various factors on compressive strength, enabling direct comparison across different studies. Based on the statistical analysis of the 28-day AISI, the key quality requirements for MSWI bottom ash as an SCM are proposed, along with the optimal mix design. This work provides valuable insights and practical guidance to support the integration of bottom ash into the cement industry.