Incorporating clay as a natural and enviro-friendly partial replacement for cement to reduce carbon emissions in peat stabilisation: An experimental investigation

Using cement for peat and soft soil foundation stabilisation has been a traditional engineering practice. However, cement production is a highly energy-intensive process and causes vast carbon emissions. This study describes a series of laboratory experiments that demonstrates the benefits of using clay as a natural and environmentally-friendly material to partially replace cement for peat stabilisation. As a pozzolanic material and filler, clay significantly improves the strength of stabilised peat and reduces the dosage of cement. For a required unconfined compressive strength level of 350 kPa, using only cement to stabilise peat would require 20.8 % of cement. By adding 40 % of clay, the cement consumption is reduced to 12.0 % (a 42.3 % saving) to stabilise the same peat. Scanning Electron Microscope (SEM) observations revealed a dense microstructure of the stabilised peat due to the filler effect and pozzolanic activity of the clay. The present study confirmed the feasibility of using clay as a partial replacement for cement in peat stabilisation. This study shall inform engineering practice for peat stabilisation with a view to contributing to the global mission of carbon neutrality by 2050.