Experimental and FEM Investigation of Cob Walls under Compression

Table 3

For each specimen, compressive strength f_c and related strain ɛ_fc, elastic moduli and Poisson’s ratio computed at 0.6 and 1/3f_c (E₀₁, ν₀₁ and E_1/3, ν_1/3, resp.), and mean internal and external water contents (ω_i and ω_e,, resp.) are reported. The compression stresses related to the formation of the first capillary cracks (σ₁, end of the first phase) and those related to the formation of diffuse cracks (σ₂, end of the second phase) are also reported (Figure 6).

Sample ID	σ1 (MPa)	σ2 (MPa)	fc (MPa)	ɛfc (%)	E01 (MPa)	E1/3 (MPa)	ν01 (−)	ν1/3 (−)	ωi (%)	ωe (%)
Wall B	0.17	0.69	1.05	7.85	16.56	15.51	0.09	0.06	3.94	4.26
Wall C	0.16	0.68	1.17	7.14	17.72	15.51	0.21	0.13	5.03	4.54
Wall D	0.11	0.73	1.13	7.89	16.43	15.08	0.06	0.03	3.27	3.83
Mean value	0.15	0.70	1.12	7.63	16.90	15.37	0.12	0.07	4.08	4.21
CV (%)	21.92	3.28	5.47	5.53	4.20	1.62	66.14	69.98	21.77	8.49
R^2range	—	—	—	—	0.97–0.99	0.97–0.99	0.93–0.94	0.57–0.81	—	—