摘要
CCUS(碳捕获、利用与封存)环境下常规波特兰水泥耐CO_(2)腐蚀性能较差,不能满足长期安全封存要求。磷酸盐改性高铝水泥可以改善高铝水泥强度衰退问题,水泥石具有较高的耐CO_(2)腐蚀性能。测试添加不同类型磷酸盐和加量后水泥石抗压强度,分析磷酸盐类型和加量对抗压强度的影响,结合矿物组成、微观形貌以及孔隙结构等方面特征揭示改性水泥强度机制。结果表明:磷酸盐的本身性质对高铝水泥抗压强度影响较大,优选出SHMP作为高铝水泥改性材料,可以显著提高改性后水泥的抗压强度且后期强度不倒缩;同一龄期下,随着SHMP掺量增加,CAP材料抗压强度先增大后减小,再增大后趋于稳定,在SHMP掺量为3%抗压强度达到最大值;SHMP加量3%时会生成少量C-A-P-H凝胶,其依附在结晶铝酸钙水合物上,并填充在水泥颗粒之间,在水泥基质中形成网状结构更有利于强度的后期发展;SHMP会抑制/转化铝酸钙水合物的生成,即SHMP加量越多铝酸钙水合物生成越少,C-A-P-H凝胶生成越多。
Conventional Portland cement in CCUS(carbon capture,utilization and storage)environment has poor CO_(2)corrosion resistance,which cannot meet the long-term safe storage requirements.Phosphate-modified high-alumina cement can improve the strength degradation problem of high-alumina cement,and the cement stone has high CO_(2)corrosion resistance.The compressive strength of the cement stone was evaluated after the addition of various types and quantities of phosphate compounds,and the influence of phosphate type and dosage on the compressive strength was analyzed.The strength mechanism of modified cement was revealed by combining the characteristics of mineral composition,microstructure and pore structure.It is shown that the inherent properties of phosphate compounds have a substantial impact on high alumina cement.Sodium Hexametaphosphate(SHMP)is selected as the modifier material of high alumina cement,which significantly improves the compressive strength of the cement without any decline in strength during the later stages.Within the same curing period,as the dosage of SHMP increases,the compressive strength of the sodium hexametaphosphate chemically bonded(CAP)material initially rises,then declines,and eventually stabilizes.The maximum compressive strength is achieved at a SHMP dosage of 3%.When the SHMP dosage reaches 3%,a small amount of C-A-P-H gel forms,adhering to the crystallized calcium aluminate hydrate,filling the gaps between cement particles,and forming a mesh-like structure within the cement matrix.This mesh structure strengthens the later-stage development of strength.Furthermore,SHMP inhibits the formation of calcium aluminate hydrate or converts it into C-A-P-H gel.Consequently,an increase in SHMP dosage leads to a decrease in the generation of calcium aluminate hydrate while promoting the formation of C-A-P-H gel.
作者
宋雨媛
郭辛阳
张文黎
步玉环
SONG Yuyuan;GUO Xinyang;ZHANG Wenli;BU Yuhuan(School of Petroleum Engineering,China University of Petroleum(East China),Qingdao 266580,China;State Key Laboratory of Deep Oil and Gas,China University of Petroleum(East China),Qingdao 266580,China;Key Laboratory of Unconventional Oil and Gas Development of Ministry of Education,China University of Petroleum(East China),Qingdao 266580,China;Quality and Safety Supervision Center,China National Logging Corporation,Xi'an 710000,China)
出处
《中国石油大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2024年第6期174-181,共8页
Journal of China University of Petroleum(Edition of Natural Science)
基金
国家自然科学基金项目(51704325,51704321)
中央高校基本科研业务费项目(18CX02103A)。
关键词
磷酸盐
高铝水泥
改性材料
抗压强度
phosphate
high alumina cement
modified material
compressive strength
