不同试验室水泥强度偏差较大原因分析及处理方法

通过两起典型案例,梳理造成水泥强度检测结果出现较大偏差的诸多因素,提出应对不同试验室水泥强度较大偏差的“一查、二看、三比较、四操作”的四步法,进而对类似问题能够快速查找原因,不同试验室水泥强度偏差较大问题得到及时有效解决.     

水泥企业与工地试验室水泥强度偏差原因查找

从水泥强度偏差较大的两起典型案例的处理入手，梳理影响水泥强度检测数据较大偏差各种因素，提出应对不同试验室水泥强度较大偏差的“一查、二看、三比较、四操作”的四步法，以便类似问题能够快速查找到原因，有助于不同试验室间水泥强度偏差较大问题得到及时有效解决。     

《水泥胶砂强度检验方法（ISO法）》试验室条件建设

水泥企业在实施ＧＢ／ Ｔ１７６７１－ １９９９《水泥胶砂强度检验方法（ＩＳＯ法）》中,首先要做的工作就是在原有ＧＢ１７７ 法的基础上,严格地按ＩＳＯ 法的技术要求认真地逐一落实有关的试验室条件建设项目, 以确保检验能顺利进行和获得应有的准确性和可靠性。     

差压式孔板流量计示值偏差较大原因分析及处理

在生产过程中,由于涉及到天然气贸易结算与计量,经常会出现天然气计量不准等问题;若不能及时解决出现的问题,会影响产品的精确计量,不仅会给生产带来偏差信息,同时也给公司带来了经济损失。塔中一联合站多使用的为罗斯蒙特3051变送器,选用标准孔板作为节流装置配合使用,组成差压式流量计测量流量。本文针对该型号流量计在塔中第一站合站生产过程经常出现的问题,总结除处理经验,对以后能够快速判断并解决同类问题具有现场实际指导意义。     

ISO标准砂水泥胶砂强度稳定性及影响因素分析

从2001年4月起,我国水泥强度检验就一直采用GB/T17671-1999《水泥胶砂强度检验方法（ISO法）》,其中所用标准砂为中国ISO标准砂。2003国家发展与改革委员会以发改运行〔2003〕2257号文颁布了《水泥强度检验用标准砂管理办法》,对标准砂砂源地与开采加工、生产与监制、经销、使用和监督管理等全过程进行了规定。     

矿物掺合料对水泥强度及水化热的影响分析

在水泥中掺入不同的矿物掺合料,研究水泥强度和水泥水化热的变化情况。结果表明：加入矿渣后,水泥胶砂的早期强度降低,但28d强度略有不同,当矿渣少于水泥用量时会增加,超过水泥用量（达到55%）时会下降。随着粉煤灰的掺入,水泥强度（3d、28d）出现了不同程度的降低。水泥的水化热与龄期呈正相关,并且无论单掺矿渣还是粉煤灰,水泥水化热都会降低。当水泥用量一定时,水泥水化热由高到低依次为同时掺入矿渣和粉煤灰、只掺矿渣、只掺粉煤灰。     

水泥自动压力试验机对水泥胶砂强度的影响分析

水泥自动压力试验机是水泥胶砂强度检测重要的设备,其性能优劣对胶砂强度结果有很大的影响。本文就水泥自动压力试验机技术指标及其对胶砂强度的影响进行简要的分析     

不同因素对粉煤灰水泥胶砂强度影响的研究

采用正交试验法探讨外加剂及工艺参数等不同因素对粉煤灰水泥胶砂强度的影响,确定水泥胶砂强度性能的最佳配方。结果表明:对粉煤灰水泥胶砂试样3d抗压强度的影响从大到小的次序为粉磨时间、激发剂掺量、水灰比、助磨剂掺量、减水剂掺量、助磨剂品种、激发剂品种;对粉煤灰水泥胶砂试样28d抗压强度的影响从大到小的次序为粉磨时间、减水剂掺量、激发剂掺量、助磨剂掺量、助磨剂品种、激发剂品种、水灰比。正交试验法确定的粉煤灰水泥胶砂试样的最佳配方为:激发剂选用Ca Cl2,掺量为2%;助磨剂选用丙三醇,掺量为0.03%;减水剂掺量为1.5%;粉磨时间为15min;水灰比为0.4。     

陕西省2022年度水泥胶砂强度实验室间比对结果分析

本文基于陕西省质量认证认可协会在2022年度开展的水泥胶砂强度实验室间比对的资料和数据,分析了实验室间比对情况,对影响水泥胶砂强度检验的因素进行了技术分析,并提出相关建议。     

醇胺类助磨剂对硅酸盐水泥水化及胶砂强度影响的研究

研究了C和D两种醇胺类助磨剂对硅酸盐水泥水化过程及胶砂强度的影响。化学结合水、水化热分析、综合热分析及XRD结果表明,C加快了水泥3d水化放热和28d水化速度及水化放热,促进了铁铝酸盐矿物的水化;D加快了水泥3d水化速度和水化放热：C、D复合加快了水泥3d和28d的水化,且复合作用优于两者的叠加效应。胶砂强度结果表明,C对水泥28d胶砂抗压强度提高幅度显著;D的加入有利于提高水泥3d胶砂抗压强度;C和D复合对28d抗压强度的增幅远高于两者的叠加效应。     

库内水泥强度异常下降的原因分析及解决措施

利用化学分析、物理检验、X射线衍射分析等手段对脱硫石膏和水泥性能进行了测试分析,找出影响库内水泥强度异常下降的原因,从而采取降低入磨物料综合水分、 改变脱硫石膏使用比例、 调整出磨水泥质量指标及降低水泥的储存温度的措施。     

Bone cement strength after different methods of mixing

During the mixing of methyl methacrylate bone cement for use in orthopaedic surgery, unpleasant and possibly harmful fumes are emitted. In an attempt to overcome this problem, three samples of bone cement were prepared by two methods. The effect on the duration of curing and the mechanical properties of the cement after curing have been studied. The samples showed to significant variation in strength when prepared by the different routes. The unconventional method of preparing the cement in a polythene sachet is particularly recommended for Simplex bone cement.     

不同水灰比和流动度对水泥抗压强度的影响

<正>1问题的提出及分析在日常处理水泥质量用户投诉的过程中,不管什么环境温度和湿度条件下,我们都会碰到养护到期的混凝土表面起粉起砂现象,而所用水泥包括袋重在内的各项品质指标现场抽检结果均合格。分析认为,这主要是拌合水偏多,振动时比重轻的混合材浮在面上,造成了表面胶结能力差而引起的。     

Mechanical properties of ZrB2 ceramics determined by two laboratories

The mechanical properties for zirconium diboride (ZrB₂) were measured at two laboratories and compared. Two billets of ZrB₂ were prepared by hot-pressing commercial powder. The relative densities of the billets were >99% and with an average grain size of 5.9 ± 4.5 µm. Both laboratories prepared American Society for Testing and Materials (ASTM) C1161 B-bars for strength and ASTM C1421 bars with notch configuration A for fracture toughness. Specimens were machined by diamond grinding at the Army Research Laboratory (ARL) and electrical discharge machining (EDM) at Missouri S&T. Strength bars tested at Missouri S&T were polished to a .25 μm finish while the bars were tested as-ground at ARL. Strengths were 473 ± 79 MPa for the Missouri S&T bars and 438 ± 68 for the ARL bars while the fracture toughness values were 3.9 ± .7 MPa•m^1/2 for the Missouri S&T bars and 4.4 ± .6 MPa•m^1/2 for the ARL bars. Vickers hardness was measured by both laboratories over a range of indentation loads. The resulting hardness values were on the low end of previously reported values and were quite different from each other especially at indentation loads ≤20N. The study demonstrated that the properties of materials tested to ASTM standards at different laboratories can be compared directly. In addition, strength and fracture toughness were nearly identical for bars prepared by conventional diamond grinding or EDM.     

水泥抗压强度改善分析与处理措施

助磨剂被广泛的用于水泥生产中,在探讨水泥粉磨影响因素时,需要开展实验评价其在粉磨效率和水泥质量的影响程度,分析在特定工厂的使用效果。水泥颗粒分布与最佳性能水泥RRSB方程对比分析,可以作为调整水泥细度的依据。S厂的实验结果表明,水泥细度在45μm17%且80μm3%,3d水泥抗压强度≥31.3MPa,28d水泥抗压强度≥48.3MPa,较出厂水泥抗压强度目标值分别高出5.3MPa和3.3MPa。     

我国大型水泥企业水泥粒径分布检测与分析

<正>0引言笔者于2009年8月18日～9月19日,走访了北京琉璃河、芜湖海螺、英德海螺、卫辉天瑞、徐州中联、青州中联、英德台泥、湖北亚东、唐山冀东、济南山水、武穴华新、河南同力、吉林亚泰、广东塔牌、福建水泥、广州越堡、荆门葛洲坝、浙江长兴、兰溪红狮和鼎鑫水泥20家大型水泥集团水泥厂;于2009年11月27     

Effect of different surface shapes formed by femtosecond laser on zirconia-resin cement shear bond strength

Objective: The purpose of this study was to evaluate the effect of different surface shapes formed by femtosecond (FS) laser on zirconia (Y-TZP)-resin cement shear bond strength (SBS). Background data: All ceramic restoration is used as an alternative to metal-ceramic restorations, due to its better aesthetics, strength, and toughness properties. However, bond strength of restoration to tooth and other materials is effective to long term success of the restoration, and to achieve it surface treatment is required on ceramic surface. Materials and methods: Forty square-shaped zirconia samples were prepared and assigned to four groups of 10. The details of the groups are as follows: Group A, square-shaped recessed surface; Group B, square-shaped projection surface; Group C, circular-shaped recessed surface; Group D, circular-shaped projection surface. The SBSs values were performed with a universal testing machine at a crosshead speed of 1 mm/min. The data were analyzed statistically using analysis of variance (ANOVA) and Tukey HSD multiple comparisons tests. Results: The one-way ANOVA results on SBSs of the zirconia material bonded with resin cement revealed significant differences among the groups (p < 0.05). The Tukey HSD test results revealed that Group B and D had significantly higher SBS values than other groups (p < 0.05), but there were no significant differences between each other (p > 0.05). Additionally, Group A and C had significantly lower values than other groups (p < 0.05). Conclusions: Different surface shapes formed by FS laser provided a significant increase in SBSs. The SBS values of projection surfaces of circular and square-shapes are greater than that of recessed surfaces of circular and square-shapes.     

水泥胶砂强度检验误差的分析

为加强水泥产品质量的监督管理,我国已形成了国家、省、市三级水泥产品质量监督网,同时,还建立了各级别的相互对比验证检验制度,保证了产品质量的稳定。但有少数企业反映,28d抗压强度测量结果相差较大,甚至出现了产品等级划分差异。对此,本文就产生误差的原因作一分析。