【作者】 范磊；

【导师】 隋同波； 田培；

【作者基本信息】 中国建筑材料科学研究院 ， 材料学， 2003， 硕士

【摘要】 本研究以高贝利特水泥(HBC)为主要胶凝材料，成功配制出了强度等级为C50～C80的高贝利特水泥高性能混凝土，该级别范围内的高贝利特水泥高性能混凝土初始坍落度≥180mm，90min坍落度损失≤40mm，且抗冻等级≥F300，抗渗等级≥W25，氯离子渗透值＜1000库仑。并与普通水泥(OPC)混凝土作对比，较系统地研究了高贝利特水泥高性能混凝土的工作性能、物理力学性能、耐久性能以及亚微结构等，为低钙高性能硅酸盐水泥的产业化以及工程应用提供了技术支撑。 1．对高贝利特水泥高性能混凝土工作性能的研究结果表明，高贝利特水泥与高效减水剂具有良好的适应性，表现为初始流动度较大，经时损失较小，具有明显的饱和点且饱和点掺量较小；此外，优质的矿物掺和料如一级粉煤灰能明显改善HBC混凝土的工作性能；更为突出的是HBC混凝土在低水胶比的情况下表现出更为优异的工作性，这一特性预示着高贝利特水泥更适宜配制水胶比很低的超高强混凝土。 2．研究了高贝利特水泥高性能混凝土的抗压、抗折、劈拉、弹性模量等一系列物理力学性能，结果表明，和OPC混凝土相比，HBC混凝土早期(3d、7d)抗压强度、抗折强度、劈拉强度、弹性模量较低，但随着龄期的增加，HBC混凝土28d诸项强度基本与之持平，90d则全面超过OPC混凝土；探讨了高贝利特水泥高性能混凝土水胶比与28d抗压强度的关系以及C50～C80强度范围内高贝利特水泥高性能混凝土7d强度与28d强度的关系；此外，对粉煤灰掺量及品种对高贝利特水泥高性能混凝土抗压强度的影响也进行了研究。 3．通过对高贝利特水泥高性能混凝土的一系列耐久性能包括抗冻、抗渗、抗碳化、抗侵蚀、干缩以及其各龄期的亚微结构等的研究，得出：高贝利特水泥高性能混凝土具有良好的抗冻、抗渗、抗碳化及抗侵蚀性能并且干缩较小。 4．孔结构研究表明：和OPC混凝土相比，HBC混凝土早期(3d、7d)最可几孔径较大，但随着龄期的增加，其后期最可几孔径大幅度下降，90d、180d时则小于OPC混凝土的最可几孔径；随着龄期的增加，HBC和OPC混凝土的多害孔急剧减少，而少害孔和无害孔则大幅度增加，其中尤以HBC混凝土其孔径小于20nm的无害孔较OPC混凝土增加最多，这是HBC混凝土后期诸项性能优良的主要原因之一。更多还原

【Abstract】 R&D of high strength HPC with strength grade C50 - C80 was conducted using high belite cement (abbreviated as HBC) as the main component of cementitious material. The workability, physical mechanical properties, durability and sub-microstructure of HBC concrete have been researched systematically in comparison with HBC using ordinary Portland cement (abbreviated as OPC). The resultant HBC concrete possesses the properties of initial slump>180mm,slump loss at 90min< 40mm,freeze resistance grade>F300,permeability resistance grade>W25 and Cl- penetration value <1000 coulom and the following research results have been obtained.1. The results of research on the workability of HBC concrete show that HBC concrete, when compared with OPC concrete, has excellent compatibility with superplasticizer, in terms of better initial fluidity, less slump loss, definite saturation point and less dosage at saturation point. In addition, good mineral admixture such as I class fly ash can obviously improve the workability of HBC concrete. Moreover, HBC concrete exhibits more excellent workability under the condition of low w/c ratio, which indicates HBC is more suitable for making super high strength concrete whose w/c ratio is very low.2. The research results indicate that the physical mechanical properties of HBC concrete such as compressive strength, flexural strength, splitting tensile strength, elasticity modulus and etc. is equivalent to that of OPC concrete at age of 28d and remarkably surpasses OPC concrete at 90d though its early age strength (3d, 7d) is relatively lower. Moreover, the relation of w/c ratio of HBC with compressive strength as well as strength at 7d with 28d (C50 - C80) has been established and the effect of the dosage and type of fly ash on compressive strength of HBC has also been studied.3. The results of research on durability of HBC concrete including resistance of freeze-thaw, permeability, carbonation, corrosion as well as shrinkage and sub-microstructure structure exhibit HBC concrete has good properties of freeze-thaw resistance, permeability resistance, carbonation resistance, corrosion resistance and less shrinkage compared with OPC concrete.4. The study on pore structure shows that the incremental pore size of HBC concrete (3d, 7d) is relatively larger, approximately equivalent at 28d, but smaller at 90d and180d compared with OPC concrete. The harmful pore of both HBC and OPC concrete decreases sharply but little harmful and harmless pores increase greatly, especially the harmless pore whose pore size is less than 20nm for HBC concrete increases much more than OPC concrete, which can explain why HBC concrete possesses excellent long term properties.更多还原