Study of the impact of bentonite on the physico-mechanical and flow properties of cement grout

Figures & data

Figure 1. Sample bentonite of Maghnia.

Table 1. Chemical, physical and mechanical proprieties of cement and bentonite

Chemical composition (%)	CEM II	Bentonite	Physical and mechanical properties of cement (CEM II)
SiO2	16.96	56.37	Specific gravity	3.15
Al2O3	4.96	17.40	Initial setting time (min)	170
Fe2O3	2.87	1.84	Final setting time (min)	265
MgO	1.96	2.78	Blain fineness (cm^2/g)	3,545
CaO	58.13	1.39	Normal consistency (%)	25.8
Na2O	0.12	3.21	Expansion (mm)	<2,5
K2O	0.54	1.70	Withdrawal at 28 days (μm/m)	<1,000
P2O5	0.13	0.03	Compressive strength(MPa)
SO3	2.21	0.09	2-days	12.3
TiO2	0.24	0.10	7-days	27.6
Loss on ignition	12.16	15.08	28-days	48.5
SiO2 + Al2O3 + Fe2O3	–	75.61	C3A (%)	7.1

Figure 2. Particle size analysis of bentonite.

Figure 3. Particle size analysis of CEM II.

Figure 4. XRD pattern of cement.

Figure 5. XRD pattern of bentonite of Maghnia.

Figure 6. Mini-slump test for cement grout: (a) mini cone (b) measurement of spread diameter.

Figure 7. Slump values of different mixes.

Figure 8. Fresh grouts density of different mixes.

Figure 9. Variations of bleeding with contents of bentonite.

Figure 10. Bleeding of cement grout: (a) Absence of bentonite (b) Presence of bentonite.

Figure 11. Water absorption of samples containing bentonite.

Table 2. Compressive strength of grouts and strength activity index at 28 days

Bentonite content in grout (%)	Compressive strength (MPa)	Strength activity index (%)
0	28.16	100.00
8	28.14	99.92
10	28.10	99.78
12	28.09	99.75
14	27.73	98.47
16	27.50	97.65
18	26.43	93.86