Effect of crystalline admixture and superabsorbent polymer on the self-healing and mechanical properties of basalt fibre mortars

Figures & data

Figure 1. Appearance of SAP and CA.

Table 1. Chemical and physical properties of cement, CA, and SAP.

Oxide content（% Weight）	OPC	CA	SAP
CaO	64.84	57.50
SiO2	2.14	15.32
Al2O3	4.94	5.18
Fe2O3	3.83	2.48
Na2O	0.25	1.83
K2O	0.88	0.80
SO3	3.02	2.90
MgO	1.34	13.20
(C3H3NaO2)n			100
Density (g/cm^3)	3.1	1.17	1.32
Particle size（mm）	0.08–.16	0.04	0.15

Table 2. Dosage of different basalt fibre mortar specimen components.

Group	Code	Sand (g)	Cement (g)	CA (g)	CA/C (%)	SAP (g)	SAP/C (%)	BF (g)	BF/C (%)	Water (g)
CS0–0	M0	3600	1800					3.6	0.2	900
CS.25–0	M1	3600	1795.5	4.5	0.25			3.6	0.2	900
CS.5–0	M2	3600	1791	9	0.50			3.6	0.2	900
CS0–.1	M3	3600	1800			1.8	0.1	3.6	0.2	900
CS0–.2	M4	3600	1800			3.6	0.2	3.6	0.2	900
CS.25–.1	M5	3600	1795.5	4.5	0.25	1.8	0.1	3.6	0.2	900
CS.25–.2	M6	3600	1791	4.5	0.25	3.6	0.2	3.6	0.2	900
CS.5–.1	M7	3600	1795.5	9	0.50	1.8	0.1	3.6	0.2	900
CS.5–.2	M8	3600	1791	9	0.50	3.6	0.2	3.6	0.2	900

Figure 2. Compressive strength of different specimens at (a) 3 days (b) 7 days (c) 28 days.

Table 3. Compressive strength and standard deviation of specimens.

Group	Code	CS-3 (MPa)	S-D	CS-7 (MPa)	S-D	CS-28 (MPa)	S-D
CS0–0	M0	30.8	2.26	38.8	3.35	47.2	3.06
CS.25–0	M1	31.6	2.52	37.2	1.81	43.5	3.19
CS.5–0	M2	30.1	3.12	33.5	3.21	47.1	1.74
CS0–.1	M3	26.7	2.38	33.4	1.53	41.0	2.34
CS0–.2	M4	24.5	0.76	31.2	1.32	39.5	1.31
CS.25–.1	M5	27.4	1.15	32.0	1.27	36.3	1.98
CS.25–.2	M6	25.8	3.08	29.4	1.35	36.8	1.91
CS.5–.1	M7	27.8	1.59	34.2	2.37	4.8	3.17
CS.5–.2	M8	27.9	1.19	29.0	3.96	38.4	1.69

Figure 3. Compressive strength of different specimens after conditioning in water: (a) 3 days, (b) 7 days, (c) 28 days.

Figure 4. Strength repair rates of different specimens after conditioning in water: (a) 3 days, (b) 7 days, (c) 28 days.

Table 4. Repair strength and standard deviation of specimens.

Group	Code	RS-3 (MPa)	S-D	RS-7 (MPa)	S-D	RS-28 (MPa)	S-D
CS0–0	M0	25.6	1.01	27.8	1.51	37.6	1.31
CS.25–0	M1	28.8	1.53	29.2	1.37	39.5	2.83
CS.5–0	M2	24.5	1.80	36.5	2.21	42.3	3.32
CS0–.1	M3	25.1	1.16	28.6	3.23	36.2	3.01
CS0–.2	M4	26.3	1.35	30.8	0.78	40.3	2.40
CS.25–.1	M5	30.4	1.04	31.3	0.10	36.5	3.97
CS.25–.2	M6	29.8	1.96	26.2	0.93	34.8	4.47
CS.5–.1	M7	25.2	1.14	33.3	2.84	42.3	3.07
CS.5–.2	M8	27.7	1.21	27.3	1.18	37.5	2.37

Figure 5. Self-healing of control mortar at 3, 7 and 28 days.

Figure 6. Self-healing of basalt fibre mortar mixed with CA only at 3, 7 and 28 days: (a) small cracks, (b) large cracks.

Figure 7. Self-healing of basalt fibre mortar mixed with SAP only at 3, 7 and 28 days.

Figure 8. Self-healing of basalt fibre mortar mixed with both CA and SAP at 3, 7 and 28 days.

Figure 9. Self-healing product morphology at the crack surface.

Figure 10. Shape of the spherical self-healing product at the surface of the fracture.

Figure 11. Shape of self-healing products around basalt fibres inside the fracture.

Figure 12. Shape of the lamellar self-healing products around the basalt fibres inside the fracture.

Figure 13. Shape of the needle-like self-healing products around the basalt fibres inside the fracture.

Figure 14. Shape of the self-healing product at the SAP inside the fracture.

Figure 15. Shape of the needle-like self-healing product at the SAP inside the fracture.

Figure 16. EDS analysis of self-healing products at the crack surface.

Figure 17. EDS analysis of the internal self-healing products of cracks.