Strength, durability and leaching properties of concrete paving blocks incorporating GGBS and SF

• Addition of GGBS and SF results in greater strengths in comparison to control mix.
• High SiO2 content in SF and CaO in GGBS increase durability properties of concrete paving blocks.
• Leaching properties of blocks with GGBS and SF decrease.
• However satisfying performance for protection of leachate to ground sources.

Ternary blends are a response to the economic and environmental pressure to reduce the cement content of concrete paving blocks. The cementitious materials used to replace Ordinary Portland cement (OPC) were Ground Granulated Blast Furnace Slag (GGBS) and Silica fume (SF). The study reported on the optimised mix from analysis of cement paste cubes. Thereafter the two mixes with the greatest strength were produced in the factory. The study successfully reduced the cement content of concrete paving blocks by 40% and managed to achieve greater strengths than the control mix. The leaching analysis reported that the higher permeability of mixes containing cement replacements resulted in these mixes absorbing less leachate, however gave satisfying performance for protection of leachate to ground sources.