纤维素醚分子参数对水泥浆力学性能的影响

Influence of Cellulose Ethers Molecular Parameters on Mechanical Properties of Cement Pastes

本文比较了纤维素醚分子参数和掺量对水泥浆力学性能的影响,结果表明,纤维素醚会增加水泥浆的孔隙率,降低水泥浆的抗压强度和抗折强度,且抗压强度的降低幅度要大于抗折强度;纤维素醚的粘度或分子量越高,或者表面活性越大,其改性水泥浆的强度越低;羟乙基纤维素醚(HEC)改性水泥浆的强度比含甲基的纤维素醚改性水泥浆的强度高;随着纤维素醚掺量增加,水泥浆的抗压强度逐渐降低并趋于稳定,抗折强度则经历增加、降低、稳定和微增加的过程。

Influence of molecular parameters and dosage of cellulose ethers on the mechanical properties of cement pastes is compared in this article. The results show that cellulose ethers increase the porosity of cement pastes and decrease their compressive strength and the flexural strength. The scale of compressive strength decreased is higher than that of flexural strength decreased. The higher the viscosity/molecular weight of cellulose ethers is, or the larger the surface activity of cellulose ethers is, the lower the strength of cement pastes is. The strength of cement pastes modified by hydroxyethyl cellulose ethers （HECs） are obviously higher than that of cement pastes modified by cellulose ethers with methyl. With the increase of cellulose ethers dosage, the compressive strength of cement pastes decrease gradually up to stabilization, and the flexural strength of cement pastes experience the process of increase, decrease, stabilization and slight increase.