共查询到20条相似文献,搜索用时 62 毫秒
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<正>1简介低热硅酸盐水泥(以下简称低热水泥)是我院从水泥工业的节能降耗以及提高混凝土的安全性与耐久性出发,研制成功的具有工作性能优良、水化热低、后期强度高及耐久性好的新型胶凝材料,可应用于各类工程,尤其适用于大体积混凝土工程(如水工大坝)建设。低热水泥突破了传统硅酸盐水泥熟料以C3S为主导矿物的组成设计,在制备技术上解决了C2S矿物活化和高活性晶型的常温稳定两大国际难题,在国内 相似文献
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通过对比研究了高分子聚合物(HP-SRA)对泵送混凝土拌合物的工作性能、力学性能、体积稳定性、早龄期开裂性能和抗氯离子渗透性能的影响。结果表明:HP-SRA在泵送混凝土拌合物中具有良好的减水效果和保坍性能;HP-SRA的添加对泵送混凝土的抗压强度、抗折强度和劈裂抗拉强度不会产生不利影响;HP-SRA对泵送混凝土的干燥收缩和早龄期自收缩具有抑制作用,能大幅提高或有效改善泵送混凝土的早龄期抗裂性能和抗氯离子渗透性能。 相似文献
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立筒预热器窑生产低热矿渣硅酸盐水泥的研究 总被引:1,自引:0,他引:1
低热矿渣硅酸盐水泥主要用于大坝或大体积建筑物及水利工程。我省现有水利工程所使用的均为普通水泥,由于普通水泥的水化热大,混凝土导热率低,水泥水化时放出的热量不易散发,可使内部温度升高,最高可达60℃以上,混凝土因温差产生拉应力,使混凝土内部出现微裂纹,致使混凝土的耐久性能下降,从而对大坝造成危害。低热矿渣硅酸盐水泥在性能上克服了普通水泥水化热高和放热速率大的缺点。我们与庆安冶金水泥厂合作,在该厂Φ25m×45m捷克型第三代立筒预热器回转窑上试制低热矿渣硅酸盐水泥。1原燃材料的选择选用的原燃材料分析结果见表1… 相似文献
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采用自然浸泡和于湿循环的方法,研究了粉煤灰混凝土(FAC)、高性能混凝土(HPc)和高性能混杂纤维增强膨胀混凝土(mPHFREC)在5%硫酸镁溶液中的相对动弹性模量变化和质量损失规律.实验结果表明:硫酸镁环境对混凝土具有严重腐蚀性;干湿循环加速混凝土的表面剥落,对混凝土的抗硫酸镁腐蚀性能有劣化作用.在5%硫酸镁中自然浸泡,HPHFREC2具有优良的抗腐蚀性能,三元纤维混杂起到良好的增韧阻裂作用;在干湿循环+硫酸镁双重破坏因素作用下,HPC有较好的抗腐蚀性能,而HPHFREC的纤维增强效果不佳,表面剥落严重,抗腐蚀性能不理想. 相似文献
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自生体积变形是评价大坝混凝土抗裂性能的关键指标之一,但一直以来针对原材料对混凝土自生体积变形的影响缺乏系统全面的试验研究。本文选用三种水泥、四种粉煤灰、两种骨料、两种膨胀剂,采用原材料逐项替换的方式成型大坝全级配和湿筛二级配混凝土试件,测试其自生体积变形。试验结果表明,全级配混凝土的自生体积变形收缩量显著低于湿筛二级配混凝土;随着水泥中MgO含量的增大,混凝土自生体积变形收缩量减小;高钙、高碱粉煤灰混凝土的自生体积变形收缩率增大;相对于花岗岩骨料,灰岩骨料混凝土的自生体积变形收缩量更小;MgO类复合膨胀剂对大坝混凝土自生体积变形具有显著的调节改善作用,但在选用时还需要同时考虑膨胀剂对混凝土微观结构、长期力学性能、耐久性等各项性能的影响。 相似文献
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研究了可厚涂高固体分涂料的固化和流挂的控制途径,及其在汽车涂装中的应用,以达到保护环境、节能的目的。提出了该涂料的固化可通过优化催化剂用量和固化条件来控制,流挂可通过添加流动控制剂来控制,并列举了它们的试验结果。 相似文献
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A new laboratory kiln was developed and built to perform over a very wide range of drying conditions. For example, the dry bulb temperature can vary from 30°C to 150°C and the dew point can be adjusted between 20°C and 130°C. Obviously, with such a high level of dew point, pressures over atmospheric pressure may be induced inside the chamber. For this reason, the kiln has been designed to withstand pressure of up to 3 bars. This kiln can also perform vacuum drying.
A programmable controller allows the temperature levels to be maintained within ± 0.2°C. Because the whole kiln can be heated only through the agitated water present at the bottom of the kiln, the load temperature can be increased up to 130°C in saturated conditions, without any change of moisture content.
The kiln has various sensors attached and is capable of withstanding severe conditions (high temperature, saturated vapour and elevated pressures). At present, air and water temperatures as well as temperature at different locations within the board can be collected during the drying process. A load cell and pressure gauges are also available. The first tests performed using this equipment are presented at the end of the paper. 相似文献
A programmable controller allows the temperature levels to be maintained within ± 0.2°C. Because the whole kiln can be heated only through the agitated water present at the bottom of the kiln, the load temperature can be increased up to 130°C in saturated conditions, without any change of moisture content.
The kiln has various sensors attached and is capable of withstanding severe conditions (high temperature, saturated vapour and elevated pressures). At present, air and water temperatures as well as temperature at different locations within the board can be collected during the drying process. A load cell and pressure gauges are also available. The first tests performed using this equipment are presented at the end of the paper. 相似文献
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ABSTRACT A new laboratory kiln was developed and built to perform over a very wide range of drying conditions. For example, the dry bulb temperature can vary from 30°C to 150°C and the dew point can be adjusted between 20°C and 130°C. Obviously, with such a high level of dew point, pressures over atmospheric pressure may be induced inside the chamber. For this reason, the kiln has been designed to withstand pressure of up to 3 bars. This kiln can also perform vacuum drying. A programmable controller allows the temperature levels to be maintained within ± 0.2°C. Because the whole kiln can be heated only through the agitated water present at the bottom of the kiln, the load temperature can be increased up to 130°C in saturated conditions, without any change of moisture content. The kiln has various sensors attached and is capable of withstanding severe conditions (high temperature, saturated vapour and elevated pressures). At present, air and water temperatures as well as temperature at different locations within the board can be collected during the drying process. A load cell and pressure gauges are also available. The first tests performed using this equipment are presented at the end of the paper. 相似文献
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本实验制备了高氯卤化银立方体系列乳剂和高氯卤化银(100)晶面T颗粒乳剂,对高氯卤化银立方体乳剂进行了不同种类掺杂剂的掺杂试验。通过测定以上各乳剂在常规曝光和高照度曝光下的照相性能,表明了在高氯卤化银乳剂中掺杂碘化物、掺杂铱络合物和掺杂浅电子陷阱杂剂都可以不同程度地改善乳剂的高照度性能,几种改进措施的结合效果更好。 相似文献
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高流动性,超高韧性聚丙烯共混材料的研制 总被引:17,自引:1,他引:16
论述制备高流动性、超高韧性聚丙烯共混物的主要影响因素,重点讨论了聚丙烯基体树脂的种类和滑石粉含量对共混物性能的影响。 相似文献
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高效吹脱法+折点氯化法处理高氨氮废水 总被引:3,自引:0,他引:3
以某化工生产企业废水为例,介绍高效吹脱法+折点氯化处理高氨氮废水的工程实例。该工程设计规模为3000m3/d,即125m3/h,进水NH3-N质量浓度高达1200mg/L。实践表明,采用该工艺处理高氨氮废水效果很好,出水NH3-N质量浓度小于15mg/L,可达污水综合排放标准(GB8978-1996)一级排放标准。 相似文献