Effects of Using Municipal Solid Waste Incineration Tailings as Lightweight Aggregate on the Mechanical Properties of Specified Density Concrete

Municipal solid waste incineration tailings were used as lightweight aggregate(MSWIT-LA)in the preparation of specified density concrete to study the effects on compressive strength, axial compressive strength, flexural strength, microhardness, total number of pores, pore area, and pore spacing. The results showed that the internal curing and morphological effects induced by an appropriate quantity of MSWIT-LA improved the compressive response of specified density concrete specimens, whereas an excessive quantity of MSWIT-LA significantly reduced their mechanical properties. An analysis of pore structure indicated that the addition of MSWIT-LA increased the total quantity of pores and promoted cement hydration, resulting in a denser microstructure than that of ordinary concrete. The results of a principal component analysis showed that the mechanical response of specified density concrete prepared with 25% MSWIT-LA was superior to that of an equivalent ordinary concrete. It was therefore concluded that MSWIT-LA can be feasibly applied to achieve excellent specified density concrete properties while utilising municipal solid waste incineration tailings to protect the environment and alleviate shortages of sand and gravel resources.