Stabilization of soil by means alternative alkali‐activated cement prepared with spent FCC catalyst

Abstract

Alkali-activated cements are widely studied as alternative and sustainable binder in soil stabilization. In this research work, a mold was designed and constructed, which allowed small cubic specimens to be made (40 × 40 × 40 mm 3). With the newly designed mold, cubic samples of soil stabilized with portland cement (OPC) and alternative AAC (based on spent fluid catalytic cracking catalyst FCC) were prepared from which compressive strength was obtained. Cylindrical specimens were also prepared using the same binders as in the previous case to obtain their compressive strength. The results obtained in both cases were compared. Greater resistances for cubic samples were achieved. The cubic specimens were selected for being better in terms of standard deviation of compressive strength for AAC stabilized soil. The obtained compressive strength and standard deviation results were compared between the soil specimens stabilized with different stabilizers cured at 7, 14, 28, and 90 days. The method allows small-sized cubic specimens to be prepared. It improves ergonomics. It also facilitates a large number of specimens being obtained with a small amount of sample. Soil stabilized with AAC yielded higher compressive strength after 90 days compared to that with OPC.

Sustainable Soil-Compacted Blocks Containing Blast Furnace Slag (BFS) Activated with Olive Stone BIOMASS Ash (OBA)

“…This means that the reaction for OPC was faster and more effective than the alkaline reaction of BFS with OBA. After 28 curing days, the Rc of the OBA/BFS blocks was 18.5 ± 2.0 MPa, a significantly lower value than that obtained [31] for the OPCstabilized block (24 MPa). However, for longer curing times (120 days), the Rc for the OBA/BFS…”

“…For comparison purposes, the soil/OPC samples (1000 g of soil, 100 g of CEM I 42.5R and 97 g of water) were prepared. This sample type showed [31] a strength of 14 MPa. This means that the reaction for OPC was faster and more effective than the alkaline reaction of BFS with OBA.…”

“…After 7 curing days, Rc was 12.5 ± 1.3 MPa: this is a very high value and such behavior was attributed initially to the high-energy compacting process. Under the same conditions, soil was compacted with no cementing component [31] and strength went below 3 MPa. This means that the reaction between OBA and BFS was effective in cementing contribution terms.…”