Table 5 Effect of auxiliary activators on the properties of different matrices activated with CaO

Tian et al., (2021)

Slag

Al₂(SO₄)₃

0.5–3%

Paste

Room

- Decreased setting time

- Increased compressive strength

Wang et al., (2021)

MK

Na₂SO₃

Na₂SO₃/CaO = 1/0.82

Paste

Room

- Increased compressive strength

Wang et al., (2018)

Slag

Na₂CO₃

Na₂CO₃/CaO = 5/2.5

Paste

20 ± 1 °C with RH ≥ 90%

- Increased compressive strength by 197%, 46.67% and 25% at the ages 3, 7 and 28 days

Burciaga-Díaz et al., (2023)

Slag

Na₂CO₃

2–4%

Paste

20 ± 2 °C with 80% RH

- Increased compressive strength

Slag

Na₂CO₃

2–4%

Paste

60 °C for 24 h

- Increased compressive strength

Zhao et al., (2020b)

Slag

Na₂SO₄

1%

Paste

20 ± 2 °C

- Decreased initial and final setting time by 11% and 17.5%

- Increased 1, 3, 7, 28 and 60 days compressive strength by 3.66, 2.38, 1.1, 1.05 and 1.07 folds

Liu et al., (2022a) Liu et al., (2022b)

Slag

CaSO₄

5%

Paste

20 ± 1 °C with ≥ 90% RH

- The obtained 1, 3, 7 and 28 days was ~ 2, ~ 13, ~ 25 and ~ 32.5 MPa, respectively

Menchaca-Ballinas and Escalante-Garcia, (2019)

Glass powder

NaOH

6% Na₂O

Mortar

60 °C for 24 h

- Increased compressive strength

Gu et al., (2014)

Slag

MgO

MgO/CaO = 0.5/0.5

Paste

20 ± 2 °C (water)

- Increased 7 days compressive strength by ~ 8%, but decreased 28 and 90 days compressive strength by ~ 9.2% and ~ 7.7

Jung-Il et al., (2020)

FA

MgO

2–8%

Paste

60 °C with 95% RH for 24 h

- Increased compressive strength

- Decreased total porosity

Magnesium formate

2–8%

Paste

60 °C with 95% RH for 24 h

- Increased compressive strength

- Decreased total porosity

Suh et al., (2023)

FA

Magnesium nitrate

2–8%

Paste

60 °C with 95% RH for 24 h

- Increased compressive strength

Zhao et al., (2020a)

FA/cement

MgO

3–30%

Paste

Autoclaved at 140, 180, 210 °C for 3–12 h

- Increased compressive strength and expansion

Yum et al., (2019)

Slag

Ca(NO₃)₂

0.5–5

Paste

23 °C with 99% RH

- Increased flowability

- 0.5% shortened setting time, whilst 1–5% increased it

- Increased 3–28 days compressive strength

NaNO₃

0.5–5

Paste

23 °C with 99% RH

- Increased flowability

- Shortened initial setting time

- 0.5% and 1% shortened final setting time, whilst 3% and 5% increased it

Yum et al., (2020)

Slag

Calcium formate

1–5%

Paste

23 °C with 99% RH

- Increased compressive strength

- Decreased total porosity

Park et al., (2016a)

Slag

Gypsum

10%

Paste

23 °C with 99.9% RH

- Increased compressive strength by ~ 50%

Slag

Gypsum

15%

Paste

23 °C with 99.9% RH

- Decreased compressive strength by ~ 30%

Djayaprabha and Nguyen, (2023)

Slag

SO₃

2.5–10%

Mortar

Room

- Increased compressive and flexural strengths

- Increased fresh density

- No effect on the flow

- No effect on the porosity up to 7.5% SO₃, whilst 10% SO₃ increased it