The changes in structural integrity and microstructure of Portland-limestone cement pastes were investigated in the course of magnesium sulfate attack at low temperature. A deterioration front, consisting of three distinct layers (brucite, gypsum, leached cement matrix), swelled in time due to the expansive nature of the deterioration products, generating cracks and subsequently detaching from the sound cement matrix, continuously promoting the process. Gypsum and thaumasite characterized the leached matrix, which experienced extensive cross-linking of the aluminosilicate structures, as a result of decalcification and dealumination of the calcium silicate hydrates (C(A)SH), impairing the overall mechanical performance. CSH of low packing density was most severely affected by the process, as confirmed by the significant drop in nano-mechanical properties. The increased rate of deterioration with limestone content was tentatively attributed to the prevalent morphology of the CSH phase. Results were validated by thermodynamic simulations, indicating that the real systems did not reach equilibrium.

研究了低温硫酸镁侵蚀过程中硅酸盐-石灰石水泥浆体结构完整性和微观结构的变化。由三个不同层（水镁石、石膏、浸出水泥基体）组成的退化前沿由于退化产物的膨胀性质而及时膨胀，产生裂缝并随后与完好的水泥基体分离，不断促进这一过程。石膏和海马石表征了浸出基质，由于硅酸钙水合物 (C (A )S H)的脱钙和脱铝，其经历了铝硅酸盐结构的广泛交联，从而损害了整体机械性能。ç小号纳米机械性能的显着下降证实了低堆积密度的 H 受该过程的影响最严重。随着石灰石含量的增加，劣化率的增加暂时归因于 C S H 相的普遍形态。结果通过热力学模拟得到验证，表明实际系统没有达到平衡。