Page 8 - ICJ Jan 2026

TECHNICAL PAPER

(a) Normal mortar 18.1 % ITZ and matrix pores (in red) (b) Bacterial mortar 8.0 % ITZ and matrix pores (in red)
Figure 4: Effect of food waste and bacteria on the microstructure of mortar [9]

Key contributions: The study demonstrates that the use of food mechanical recycling. In addition to this, previous studies have
waste can eliminate the need for synthetic nutrient media, one been conducted on a combination of different treatments,
of the highest cost contributors, and make bio-cementation waste-based slurry-fibre coating, and different surface
more cost-effective. The study also observes that the bacterium treatments. However, the same has not been reported due lack
E. Coli DH-5α favours strength enhancement over crack-filling of technical or commercial viability.
ability. This can inspire exploration of different bacteria as
specialised bio-admixture, extending beyond self-healing Cryogenic treatment uses the freeze and thaw mechanism
applications. for weakening of adhered mortar, followed by mechanical
[10]
scrubbing for removing the weakened adhered mortar . The
Limitations: The study has been limited to mortars and a process is slow and yields a small improvement in aggregate
specific set of food wastes. Further research is ongoing towards characteristics. The treatment establishes that deteriorated
identifying a suitable non-pathogenic bacterium that can work C&D waste in cold regions can be upcycled by using abrasive
with a wide range of food wastes. Furthermore, the hypothesis cleaning, without requiring additional weakening of adhered
for the effect of bacteria size on strength is based on an mortar.
observed inverse correlation between the strength and size of
bacteria across multiple literature. Further investigation in this In another study, the conventional rotatory abrasion was
direction is needed to validate the hypothesis. improved by introducing irregularities on the otherwise smooth
drum surface (Figure 5a) . The resulting surface irregularities
[11]
3.2 Treatment of C&D wastes provided additional abrasive action, lower adhered mortar
content and lesser energy consumption as compared to material
The author has explored various strategies for treatment treated in the Los Angeles abrasion machine.
and upcycling C&D wastes. This includes two novel recycling
pathways, i.e. cryogenic treatment and surface-modified Thermo-mechanical treatment is particularly suited for the
abrasion, and an improvement in the existing thermo- treatment of mixed recycled aggregates prepared from

(a) Surface irregularities (b) Rotatory device
Figure 5: Prototype for the surface-modified abrasion process

70 THE INDIAN CONCRETE JOURNAL | JANUARY 2026