甲酸钙对水泥浆体抗压强度、水化及孔结构的影响

研究了甲酸钙对普通硅酸盐水泥浆体和硅酸盐水泥浆体抗压强度的影响,采用XRD、压汞法和灼烧法,测试了甲酸钙对水泥浆体水化产物组成、孔结构及化学结合水的影响。结果表明：甲酸钙能加速水泥的水化,促进Ca（OH）2的生成,提高水泥浆体的水化程度;甲酸钙能明显改善水泥浆体的孔结构,减少孔隙率和细化孔径;甲酸钙对P·O42．5普通硅酸盐水泥浆体早期强度的提升要比对P·152．5硅酸盐水泥的效果好。     

高游离氧化钙水泥的显微结构与膨胀机理研究

运用扫描电子显微镜（SEM）研究了高游离氧化钙（f-CaO）水泥的 经及其在水泥石中氢氧化钙的分布和显微结构特征。讨论了水化早期和后期Ca(OH）2晶体的结晶特性及界面结合关系,指出了熟料中成大堆分布的f－CaO晶体缓慢水化导致Ca（OH）2晶体不断长大是造成水泥安定性不合格的主要原因。     

利用高钙粉煤灰生产粉煤灰水泥的试验研究

研究了高钙粉煤灰水泥的细度及活性激发剂对其物理性能的影响。研究结果表明,高钙粉煤灰水泥的安定性和各龄期的抗折、抗压强度均随着水泥的细度的提高和活性激发剂的掺入而提高,活性激发剂具有加速水泥矿物和ｆ Ｃａ Ｏ 水化的作用。采用５２５＃ 熟料,掺加３０％ 的高钙粉煤灰时,水泥的比表面积在３４０～４００ ｍ ２ ／ｋｇ 和掺入１％ 的活性激发剂,能够稳定生产４２５＃ 高钙粉煤灰水泥。     

缓凝剂对水泥稳定粒料土性能的影响

为了使通用水泥拌制的混合料有较长的延迟碾压时间,研究了缓凝剂ZL和木钙对水泥稳定粒料土性能的影响。研究结果表明,可以通过掺加缓凝剂的方法延长水泥稳定粒料的延迟碾压时间。ZL和木钙均可将水泥稳定碎石的延迟碾压时间延长到9h。在效果相近时,ZL比木钙更加经济适用。ZL和木钙两种缓凝剂对水泥稳定粒料土的强度发展无不良影响。     

无水硫酸钙对α-磷酸三钙骨水泥的结构与性能的影响

将无水硫酸钙（CSA）引入磷酸钙骨水泥（CPC）中,结合热分析（TG-DSC）、扫描电子显微分析（SEM）和力学性能测试等方法,通过对比试验研究了CSA对α-磷酸三钙（α-TCP）体系骨水泥结构与性能的影响.结果表明：CSA的加入对α-TCP骨水泥的结构与性能有一定的影响,是一种可提高骨水泥的抗压强度,调控固化时间的有效添加成分.     

可注射磷酸钙骨水泥的研究

可注射磷酸钙骨水泥具有良好的生物相容性、骨传导性、可降解性、易操作性及可塑性等优点，临床上可用于非负重部位骨缺损的修复、药物或生物因子载体、牙根管的充填、松质骨螺钉的加固以及骨折的固定等方面，在植入学、骨创伤学及放射介入学等领域中具有广泛的应用前景。目前可注射磷酸钙骨水泥已经成为骨水泥研究中的主要课题，就其最新研究进展进行了讨论。     

Influence of Calcium Sulfate State and Fineness of Cement on Hydration of Portland Cements Using Electrical Measurement

1 IntroductionThe calcium sulfate state includes gypsum, hemi-hydrate and anhydrite .Inthe modern Portland cement in-dustry,the gypsumis used as a setting retarder for reac-tion with C3A[1]. With the presence of gypsumin theformof CaSO4·2H2O,the gypsum dissolves and reactsprimarily with C3A and C4AF to form ettringite . Thisettringite isinitiallyformed with a veryfine-needle crystalstructure ,whichforms a diffusion barrier onthe surface ofthe cement . This coating avoids the unwanted fl…     

聚合磷酸钙骨水泥的制备和性能研究

采用丙烯酸和衣康酸的共聚物与自制磷酸钙粉末反应制备骨水泥。用自凝牙托水对类磷酸四钙（TTCP）粉末进行表面改性后所制备的骨水泥,初凝时间为4．5min,终凝时间为8.5min,抗压强度可达４２MPa。采用类TTCPα－磷酸三钙的混合粉料制备的骨水泥,初凝时间为５．５min,终凝时间为１１．０min,抗压强度可达４３MPa。     

针状硅灰石对磷酸盐骨水泥性能的影响

以磷酸氢二钾和磷酸二氢钾为固化液,以磷酸四钙、α-磷酸三钙、磷酸氢钙、焦磷酸钙、羟基磷灰石和碳酸钙为原料合成骨水泥,向其添加针状硅灰石,研究了针状硅灰石对其性能的影响。结果表明,在磷酸钙骨水泥中添加针状硅灰石可以缩短凝结时间,提高抗压强度。当针状硅灰石的添加量为3%,骨水泥性能达到最佳;其初凝时间、终凝时间分别为14和28 min,样品在Ringer’s模拟液溶液中浸泡2周后抗压强度达49.23 MPa,浸泡液的pH值变化幅度小(7.1~7.8),在安全范围之内。     

Microstructure and mechanical properties of calcium phosphate cement/gelatine composite scaffold with oriented pore structure for bone tissue engineering

The macroporous calcium phosphate(CPC) cement with oriented pore structure was prepared by freeze casting. SEM observation showed that the macropores in the porous calcium phosphate cement were interconnected aligned along the ice growth direction. The porosity of the as-prepared porous CPC was measured to be 87.6% by Archimede’s principle. XRD patterns of specimens showed that poorly crystallized hydroxyapatite was the main phase present in the hydrated porous calcium phosphate cement. To improve the mechanical properties of the CPC scaffold, the 15% gelatine solution was infiltrated into the pores under vacuum and then the samples were freeze dried to form the CPC/gelatine composite scaffolds. After reinforced with gelatine, the compressive strength of CPC/gelatine composite increased to 5.12 MPa, around fifty times greater than that of the unreinforced macroporous CPC scaffold, which was only 0.1 MPa. And the toughness of the scaffold has been greatly improved via the gelatine reinforcement with a much greater fracture strain. SEM examination of the specimens indicated good bonding between the cement and gelatine. Participating the external load by the deformable gelatine, patching the defects of the CPC pores wall, and crack deflection were supposed to be the reinforcement mechanisms. In conclusion, the calcium phosphate cement/gelatine composite with oriented pore structure prepared in this work might be a potential scaffold for bone tissue engineering.     

高掺量增钙粉煤灰水泥的研制

所研制的激活安定剂，能解决高掺量增钙粉煤灰水泥体积安定性不良的问题，提高该水泥的７ｄ，２８ｄ强度，缩短凝结时间，使增钙灰掺量高达６０％、４２％的水泥达到３２５＃、４２５＃水泥的物理性能标准。工业性实验生产出６０％增钙灰掺量的３２５＃水泥。     

硼掺合料对水泥浆体性能的影响

研究了不同含硼添加剂对水泥浆体凝结时间、抗压强度、抗折强度、结合水含量及碱度的影响,并采用XRD和SEM测试手段分析了硬化浆体微观结构,着重考察了硼元素的引入方式对水泥水化性能的影响。研究表明:硼砂、硼酐及硼玻璃粉对水泥浆体性能的影响存在很大差异。硼砂具有明显的缓凝作用;硼酐稍延缓了水泥的凝结时间,但严重影响了水泥石的力学性能,主要可能是硼酐中可溶性硼与水泥水化后的钙离子形成致密的水化硼酸钙膜,覆盖在水泥颗粒表面,阻止了水泥颗粒与外部溶液的接触,使水泥水化反应无法正常进行;而硼玻璃粉对水泥的凝结时间和力学性能均不存在不良影响。     

Effect of substitutional Sr ion on mechanical properties of calcium phosphate bone cement

A novel calcium phosphate cement was developed by adding different amount of SrO to tetracalcium phosphate during the fabrication process. The experimental results show that compressive strength of cements based on tetracalcium phosphate doped with SrO significantly increases with the increase of SrO content, approximately 60 MPa, whilst the mechanical behavior of CPC slightly decreases if 0.7wt% SrO is added. X-ray diffraction measurement confirms the setting reaction of doped cements is similar to that of pure calcium phosphate cement (CPC). Low crystalline hydroxyapatite (HA) is found to be the main constituent of set cement. A mechanical reinforcement effect is resulted from the substitution of Sr ion to Ca²⁺ in tetracalcium phosphate (TTCP), accelerating HA crystal formation and a more cross-linked cement structure. In vitro bioactivity tests showed that CPC added with 0.5wt% SrO had a more rapid degradation compared with pure CPC.     

胶结充填掺用外加剂

本文介绍了外加剂的定义、分类及应用概况，并通过分析水泥水化过程和胶结充填掺用木钙的正交试验，揭示了外加剂在胶结充填中的作用机理，为减少水泥用量，降低充填成本，提供了一种思路．     

The influence of steel slag with high Al2O3 content on the initial hydration of cement

The initial hydration of steel slag with high Al₂O₃ content and its influence on the initial hydration of cement were investigated in this study. Steel slag with high Al₂O₃ content may contain much calcium aluminate mineral but very little gypsum. The steel slag hydrates much more quickly than cement in the initial hydration period, producing many flake products which have a great influence on the fluidity, initial setting time, and adsorption level of superplasticizer of paste. Replacing part of cement by steel slag with high Al₂O₃ content can change the hydration condition of calcium aluminate mineral of the cement by decreasing the gypsum to calcium aluminate mineral ratio, resulting in accelerating the hydration rate of calcium aluminate mineral in the initial hydration period. Paste containing steel slag with high Al₂O₃ content has a shorter initial setting time, higher adsorption level of superplasticizer, and greater loss in fluidity than the pure cement paste.     

水泥熟料率值的最佳控制范围

石灰饱和比（KH值）是水泥生产中经常发生波动的一个率值,它直接影响到水泥的强度标号。本文通过对快速钙的跟踪测定分析,及时调整配料方案,对熟料的取样、化学成分的化验、试块强度的测定,最后进行计算和对比分析,找出水泥熟料饱和比（KH值）的最佳控制范围（0.88～0.92）。     

水泥熟料率值的最佳控制范围

石灰饱和比 (KH值 )是水泥生产中经常发生波动的一个率值 ,它直接影响到水泥的强度标号。本文通过对快速钙的跟踪测定分析 ,及时调整配料方案 ,对熟料的取样、化学成分的化验、试块强度的测定 ,最后进行计算和对比分析 ,找出水泥熟料饱和比 (KH值 )的最佳控制范围 (0 .88～ 0 .92 )。     

Strength development and microstructure of hardened cement paste blended with red mud

Red mud was activated to be a mineral admixture for Portland cement by means of heating at different elevated temperatures from 400 °C to 700 °C. Results show that heating was effective, among which thermal activation of red mud at 600 °C was most effective. Chemical analysis suggested that cement added with 600 °C thermally activated red mud yielded more calcium ion during the early stage of hydration and less at later stage in liquid phase of cement water suspension system, more combined water and less calcium hydroxide in its hardened cement paste. MIP measurement and SEM observation proved that the hardened cement paste had a similar total porosity and a less portion of large size pores hence a denser microstructure compared with that added with original red mud. Funded by the National 973 Program of China (No. 2001CB610703)     

Influence of cellulose ethers on hydration products of portland cement

Cellulose ethers are widely used to mortar formulations,and it is significant to understand the interaction between cellulose ethers and cement pastes.FT-IR spectra,thermal analysis and SEM are used to investigate hydration products in the cement pastes modified by HEMC and HPMC in this article.The results show that the hydration products in modified cement pastes were finally identical with those in the unmodified cement paste,but the major hydration products,such as CH(calcium hydroxide),ettringite and C-...     

不同CO2养护压力下硫铝酸盐和硅酸盐水泥浆体早期微观结构

研究硫铝酸盐和硅酸盐水泥（CSA-OPC）浆体在不同碳养护压力下的早期碳化过程,通过X射线衍射、红外光谱、热重、压汞和扫描电镜等测试方法,表征碳化前后水泥浆体的物相组成和微观结构.实验结果表明,CSA-OPC浆体的水化产物主要为钙矾石,碳化作用使钙矾石转变为碳酸钙和硫酸钙晶体;水泥中碳酸钙以3种晶型存在,其中方解石为主要存在形式.碳化使半碳型的水化硫铝酸钙（Hc-AFm相）逐渐转化为单碳型的水化硫铝酸钙（Mc-AFm相）,碳化程度和碳化深度随着碳化压力的增加而递增.碳化后CSA-OPC水化产物体积减小,样品总孔隙率增大、孔隙结构变疏松.研究结果阐明了CSA-OPC浆体在早期碳化养护条件下的微结构变化过程,为制备基于硫铝酸盐水泥的高效碳汇材料提供了技术支撑.