Reducing Cement Contents of Paving Blocks by Using Mineral Waste and by-Product Materials

摘要

In the production of conventional paving blocks, it is usual to use a minimum of 210 kg/m~3 of cement. However, when portland cement is produced, it impacts negatively on the environment due to carbon dioxide emissions. Therefore, this paper investigates the use of waste and by-product materials, such as run-of-station ash (ROSA), basic oxygen slag (BOS), ground granulated blast-furnace slag (GGBS), plasterboard gypsum (PG), and cement bypass dust (BPD) to reduce the amount of cement in paving blocks. The combinations of binary and ternary blends in different mixes are considered. Tensile strength, skid/slip and freeze/thaw resistance of paving blocks, verified that a cementitious mix containing ROSA up to 60%, GGBS up to 55%, BPD up to 25%, and plasterboard gypsum PG up to 5% by weight can replace portland cement without having any substantial impact on the strength or durability of the blocks. XRD and XRF tests of selected mixes have been presented and discussed. Concrete blocks prepared with OPC/GGBS/BPD can reduce cement content by up to 30% in comparison to the percent of cement used in factories.