摘要
通过内掺硅烷对硫铝酸盐水泥(Sulphoaluminate cement,SAC)砂浆进行疏水改性,以提升其在海洋等严酷环境中的耐久性。首先,分析了内掺不同量硅烷SAC净浆的凝结时间和水化放热行为,系统研究了硅烷掺量对不同龄期SAC砂浆力学和吸水性能的影响规律。之后,基于压汞法、扫描电镜、X射线衍射法和材料表面水分接触角等测试结果探讨了内掺硅烷SAC砂浆力学与吸水性能的演化机制。最后,研究了不同硅烷掺量SAC砂浆与不同含水饱和度旧砂浆基体间界面剪切强度的演化规律。结果表明:掺入不同量硅烷的SAC净浆仍具备速凝特征,其快速放热阶段均集中于加水拌合后的2 h内。内掺水泥质量0.5%~2%的硅烷会对SAC砂浆的抗压强度产生一定的负面影响,但会略微提升其28 d龄期时的抗折强度。1~28 d龄期内,内掺硅烷SAC砂浆试件的毛细吸水系数相较未掺试件降低了71.0%以上。内掺硅烷未造成SAC砂浆孔隙率的显著增长,但使直径大于50 nm的毛细孔体积分数升高以及水化产物含量有所增加。SAC砂浆中硅烷掺量的增加导致其表面水分接触角增大,并进一步降低了其毛细吸水性能。3 d龄期时,SAC砂浆与基体间的界面剪切强度随硅烷掺量的增加而升高,随基体饱和度的增加而降低。与不同饱和度基体粘结后,内掺硅烷SAC砂浆仍具有较低的吸水性能。
In this paper,the hydrophobic modification of sulphoaluminate cement(SAC)mortar was carried out by adding silane to improve its durability in harsh environments such as the ocean.Firstly,the setting time and hydration exothermic behavior of SAC paste with different saturation of silane were analyzed,and the influence of silane content on the mechanical and water absorption properties of SAC mortar at different ages was systematically investigated.The mechanical and water absorption evolution mechanism of silane-doped SAC mortar was further discussed based on the results of mercury intrusion porosimetry,scanning electron microscope,X-ray diffraction and surface moisture contact angle tests.Finally,the evolution law of interface shear strength between SAC mortar with different silane contents and old mortar substrates with different water saturation was investigated.The results show that the SAC pastes with different silane contents still possess quick-setting characteristics,and itsrapid exothermic stage is concentrated within 2 h after water mixing.The incorporation of silane(0.5%-2%of cement in mass)has a certain negative effect on the compressive strength of SAC mortar,but can improve its flexural strength at the age of 28 d.The capillary water absorption coefficients of SAC mortar specimens incorporated with silane are reduced by more than 71.0%compared with specimens without silane at the age of 1-28 d.The incorporation of silane does not cause a significant increase in the porosity of SAC mortar,but increases the volume fraction of capillary pores with a diameter greater than 50 nm and the content of hydration products.The increase of silane content in SAC mortar leads to the increase of its surface water contact angle and further reduces its capillary water absorption properties.At the age of 3 d,the interface shear strength between SAC mortar and substrates increases with the increase of silane content,and decreases with the increase of the saturation of substrates.The SAC mortar with silane still have low water absorption properties after bonding to substrates with different saturation.
作者
薛善彬
王丹
马金元
白如飞
郭哲名
高小建
XUE Shanbin;WANG Dan;MA Jinyuan;BAI Rufei;GUO Zheming;GAO Xiaojian(School of Civil Engineering,Qingdao University of Technology,Qingdao 266525,China;School of Civil Engineering,Harbin Institute of Technology,Harbin 150001,China)
出处
《复合材料学报》
北大核心
2025年第7期3940-3951,共12页
Acta Materiae Compositae Sinica
基金
国家自然科学基金(U2106220,52008222)
青岛市科技惠民示范专项(24-1-8-cspz-9-nsh)。
关键词
硫铝酸盐水泥
硅烷改性
毛细吸水
界面剪切强度
微观机制
sulphoaluminate cement
silane modification
capillary water absorption
interface shear strength
micro mechanism
