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Comparative Physico Mechanical Study of Cements CEM II 42.5R in Cameroon: Case of DANGOTE and CIMENCAM 预览
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作者 Thomas d’Aquin Biyindi Fabrice Kwefeu Mbakop +2 位作者 Eric Toumi Belmondo Woumbeng Etonleu Joseph Pondi 《土木工程期刊(英文)》 2019年第1期18-34,共17页
The present work deals with a comparative study of the physical-mechanical characteristics of different types of cement CEM II 42.5R produced and used in Cameroon. Indeed, the recent policy of integration and promotio... The present work deals with a comparative study of the physical-mechanical characteristics of different types of cement CEM II 42.5R produced and used in Cameroon. Indeed, the recent policy of integration and promotion of products in the sub-region has allowed some manufacturers (04) to settle in Cameroon and propose their products that characteristics are most often ignored by consumers. In order to handle this work correctly, we have conducted several tests on cements CEM II 42.5R of CIMENCAM and DANGOTE. These trials were carried out on fresh concrete, mortar, and also on a normalized cement paste. The present study mainly shows the specificities and the characteristics of CEM II 42.5R cement from other brands. 展开更多
关键词 CEMENT Compression CEM II 42.5R Concrete MORTAR
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Effects of Adding Boron Compounds to Glycol Based Grinding Aids on Cement Compressive Strengths Performance 预览
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作者 Murat ?all? Erol Pehlivan 《土木工程期刊(英文)》 2019年第1期35-45,共11页
In this study, the effect of substituting boron compounds with glycol-based grinding aids to the compressive strength performances of cement was investigated. Monoethylene glycol (MEG) and diethylene glycol (DEG) were... In this study, the effect of substituting boron compounds with glycol-based grinding aids to the compressive strength performances of cement was investigated. Monoethylene glycol (MEG) and diethylene glycol (DEG) were used as glycol-based grinding aids, and anhydrous borax and boric acid were used as boron compounds in the tests. CEM I type cement production was carried out with the addition of grinding aid mixtures to Portland clinker and some gypsum in the experiments. All produced cement samples were tested for Blaine fineness, xrf elemental analysis and 2, 7 and 28 days compressive strength tests. Test results of grinding aids of MEG and boron compounds mixture showed no increase in any age of compressive strengths performances related to MEG used itself. However, with the addition of boron compounds to DEG increased grinding aid performance at all ages (2, 7 and 28 days). Possible reasons for this increase could be borate esters formed with DEG and boric acid in a basic medium. 展开更多
关键词 Boric Acid CEMENT GLYCOL GRINDING Aid ANHYDROUS BORAX Compressive Strength
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Concrete Formulation Study for Informal and Semi-Informal Construction Sectors 预览
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作者 Narcisse Malanda Paul Louzolo-Kimbembe +2 位作者 Louis Ahouet Jarlon Brunel Makela Guy-Richard Mouengue 《土木工程期刊(英文)》 2019年第1期57-79,共23页
The present work consisted in carrying out a study on the effective formulation of concrete for an optimal resistance to compression (fc28) between 20 and 30 MPa for the sites animated by the actors of the informal an... The present work consisted in carrying out a study on the effective formulation of concrete for an optimal resistance to compression (fc28) between 20 and 30 MPa for the sites animated by the actors of the informal and semi-informal sectors of the construction. Studies have been carried out on projects under construction, by taking samples of fresh concrete in order to evaluate their real compressive strengths. These surveys show that there is a problem in the concrete formulation, as nearly 2/3 of the results show the lack of technical knowledge on concrete formulation practices. Indeed, on eight sites surveyed and whose fresh concrete samples were taken, only two sites (7 and 8) report fairly consistent results. Their 28-day compressive strength values are respectively 35.36 and 22.18 MPa. In addition, various formulations proposed with aggregates from different quarries or extracts from the bed of the Congo River, were determined in the laboratory. This study allowed us to obtain fairly objective results overall, which is characteristic of concretes of required quality. Of the six (06) formulation proposals, average resistances of 19.6 MPa at 07 days and 25.28 MPa at 28 days were obtained. These results at 28 days are in the range of 20 to 30 MPa, set as objective in this study. These formulations can be a reliable source for concrete manufacturers in these construction sectors. Similarly, the statistical study based on principal component factor analysis tests has shown that the most appropriate formulation, in terms of mechanical resistance, is that proposed with sand extracted from the Congo River (formulation 3). This is justified by the fact that this sand is consistent and has a good granular distribution. 展开更多
关键词 FORMULATION CONCRETES Aggregates Cement Physico-Mechanical Characteristics INFORMAL and Semi-Formal SECTORS
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Assessment of Physical and Mechanical Properties of Concrete Produced from Various Portland Cement Brands 预览
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作者 Asal Soltani Salim Khoso +1 位作者 Manthar Ali Keerio Antonio Formisano 《复合材料期刊(英文)》 2019年第4期327-337,共11页
Construction projects require cement, which must have definite qualities so as to play its part separately in structure. The compressive strength of cement and, consequently, its physical properties could vary as a re... Construction projects require cement, which must have definite qualities so as to play its part separately in structure. The compressive strength of cement and, consequently, its physical properties could vary as a result of variations in the raw materials, as well as in manufacturing conditions. Therefore, an experimental study has been checked out herein by investigating the mechanical and physical properties of concrete specimens by means of four different types of Ordinary Portland Cements, namely Black Bull, Lucky, Pak Land and DG obtained from the market of Sindh Pakistan. Based on obtained results, it was found that Lucky cement type performed well when compared to other three types both in compressive and tensile strength of concrete. Although there were some differences in the physical properties of cement used in this study, however, they all meet with the requirements of international standards. 展开更多
关键词 CEMENT Brands CONCRETE COMPRESSIVE STRENGTH TENSILE STRENGTH
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Assessment of Equivalent Radium Activity and Annual Effective Dose Due to Building Materials in Côte D’Ivoire by Gamma Spectrometry: Cases of Cement 预览
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作者 Monnehan G. Alain Gogon B. D. L. Huberson +3 位作者 Braffo A. Florentin Djagouri Koudou Koua A. Antonin Kouakou Omer 《应用科学(英文)》 2019年第10期774-783,共10页
Radioactivity is a natural phenomenon present in the universe. So, because of human life solidarity with a habitat, we are permanently in contact, especially through building materials. The objective of this work is t... Radioactivity is a natural phenomenon present in the universe. So, because of human life solidarity with a habitat, we are permanently in contact, especially through building materials. The objective of this work is the determination of the used cement radioactivity level in the buildings in Cote d'Ivoire. Thus, samples of grey and white cement currently used on Ivorian territory were taken. In order to determine the radioactivity level of this cement, samples were analyzed by using gamma spectrometry chain which contains a NaI (Tl) scintillation detector designed by the German manufacturer LD-DIDACTIC, coupled to a multichannel analyzer (AMC) using a Cassy Lab software. Thus, the specific activity of the primordial radionuclides 226Ra, 232Th and 40K, was able to be determined. The average values obtained are 29.66 Bq/kg, 34.88 Bq/kg and 178.424 Bq/kg respectively for 226Ra, 232Th and 40K. All average values are below the limit values recommended by UNSCEAR. However, we evaluated the radiological parameters such as the equivalent radium activity and the annual effective dose in order to translate the specific activity in terms of harmfulness. Values obtained for these parameters are below those recommended by ICRP and UNSCEAR. These results show that the risk incurred by the use of these different brands of cement is low. 展开更多
关键词 CEMENT Gamma SPECTROMETRY EQUIVALENT Radiumactivity ANNUAL Effec-tive DOSE
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水泥粉煤灰再生基层混合料性能的研究 预览
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作者 刘红科 《北方交通》 2019年第10期51-54,共4页
为了提高再生稳定碎石基层的路用性能,向集料中掺入水泥与粉煤灰比例为1∶3的结合料,展开试验研究。根据水泥稳定碎石基层配合比设计方法确定集料配合比,试验中再生骨料(10~30mm)的掺配比例依次为0%、20%、40%、60%、80%、100%,由最大... 为了提高再生稳定碎石基层的路用性能,向集料中掺入水泥与粉煤灰比例为1∶3的结合料,展开试验研究。根据水泥稳定碎石基层配合比设计方法确定集料配合比,试验中再生骨料(10~30mm)的掺配比例依次为0%、20%、40%、60%、80%、100%,由最大干密度试验确定其相应的最佳含水量。通过无侧限抗压强度试验、劈裂强度试验、冻融循环试验进行性能分析。结果表明:再生基层混合料的无侧限抗压强度、劈裂强度都随再生骨料掺配比例的增大而增大,当再生骨料掺量为80%时达到最大值;而混合料的抗冻系数BDR随再生骨料掺量的增加逐渐减小。 展开更多
关键词 水泥 粉煤灰 再生集料 基层混合料 路用性能
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浅谈水泥生产质量对水泥净浆流动度及外加剂适应性的影响 预览
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作者 刘军 马桂萍 《城市建筑》 2019年第18期169-170,共2页
影响水泥和净浆流动度及外加剂适应性的因素有:熟料质量、混合材料的种类和质量、石膏的种类和数量、水泥的碱含量、颗粒分布和温度及各种助磨剂的性能。虽然外加剂可根据实际来进行调整,但作为一个供应商,在水泥生产过程中应加强对水... 影响水泥和净浆流动度及外加剂适应性的因素有:熟料质量、混合材料的种类和质量、石膏的种类和数量、水泥的碱含量、颗粒分布和温度及各种助磨剂的性能。虽然外加剂可根据实际来进行调整,但作为一个供应商,在水泥生产过程中应加强对水泥质量的控制监督,最大限度地减少或避免因水泥质量问题而导致的一系列问题,从而积极地创造各种条件,减少用户拌混凝土的用水量。 展开更多
关键词 水泥 生产质量 水泥净浆流动度 外加剂适应性 影响
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实心椎弓根镙钉骨水泥钉道强化技术治疗伴有骨质疏松症脊柱退行性疾患的临床疗效 预览
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作者 张颖 卢钰 +9 位作者 赵智 李韬 毕尼 施志约 王迎松 解京明 宋跃明 常利涛 关帅 唐林波 《昆明医科大学学报》 CAS 2019年第11期63-68,共6页
目的评价实心椎弓根镙钉骨水泥钉道强化技术治疗伴有骨质疏松症的脊柱退行性疾患中期临床疗效及相关并发症。方法将2016年7月至2017年7月昆明医科大学第二附属医院骨科收治的需要进行脊柱内固定手术的脊柱退行性疾病患者74例分为2组。A... 目的评价实心椎弓根镙钉骨水泥钉道强化技术治疗伴有骨质疏松症的脊柱退行性疾患中期临床疗效及相关并发症。方法将2016年7月至2017年7月昆明医科大学第二附属医院骨科收治的需要进行脊柱内固定手术的脊柱退行性疾病患者74例分为2组。A组36例患者伴有骨质疏松症,采用实心椎弓根镙钉骨水泥钉道强化技术,为观察组;B组38例患者伴有骨量减少,采用传统实心椎弓根镙钉技术,为对照组。2组患者减压、融合等手术方式相同,比较2组患者术前、术后、末次随访时VAS、ODI、SF-36评分。对实心椎弓根镙钉骨水泥钉道强化技术,骨水泥在椎体内分布模式、骨水泥渗漏、骨水泥肺栓塞等相关并发症进行评估。结果2组患者平均随访时间(22.0±6.4)月。A组纳入患者36名,置入镙钉279枚,平均(7.8±3.8)枚,其中骨水泥强化镙钉195枚,平均(5.4±2.7)枚,强化椎体101个节段,检出各型骨水泥渗漏的椎体共53个,渗漏率为52.4%。B组纳入患者38名,置入镙钉210枚,平均(5.5±3.2)枚。末次随访时,2组患者VAS、ODI、SF-36评分均较术前明显改善,2组之间差异无统计学意义(P>0.05)。A组36例患者检出无症状骨水泥肺栓塞患者共11名,发生率30.5%;2名患者术中检出骨水泥椎管内渗漏。结论实心椎弓根镙钉骨水泥钉道强化技术是治疗伴有骨质疏松症的脊柱退行性疾患的有效术式,但也有较高的骨水泥渗漏相关并发症。 展开更多
关键词 椎弓根镙钉 骨水泥 骨质疏松症 骨水泥渗漏
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铜渣基草酸盐水泥的制备及其性能
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作者 王昊 罗中秋 +3 位作者 周新涛 李娜秋 张建辉 和森 《过程工程学报》 CAS CSCD 北大核心 2019年第2期427-433,共7页
以铜渣和草酸为原料,按一定比例混合,通过酸碱反应制备铜渣基草酸盐水泥,考察了铜渣与草酸质量比(CS/OA)、水灰质量比(W/C)、缓凝剂种类及掺量对所制水泥力学性能和凝结时间的影响,用扫描电镜和X射线粉末衍射仪分析了水泥的微观形貌和... 以铜渣和草酸为原料,按一定比例混合,通过酸碱反应制备铜渣基草酸盐水泥,考察了铜渣与草酸质量比(CS/OA)、水灰质量比(W/C)、缓凝剂种类及掺量对所制水泥力学性能和凝结时间的影响,用扫描电镜和X射线粉末衍射仪分析了水泥的微观形貌和物相组成。结果表明,随质量比CS/OA和W/C增加,水泥的抗压强度呈先增大后减小的趋势,凝结时间随CS/OA增大而减小,随W/C增大而增大。硼砂和三聚磷酸钠对水泥的抗压强度影响较大,随其掺量增加,水泥的力学性能降低,适量的硼酸可提高水泥的抗压强度,且具有较好的缓凝效果,可将硼酸作为较佳缓凝剂。当质量比CS/OA=4和W/C=0.16~0.17、硼酸掺量为2.5wt%时,材料性能最优,养护28 d抗压强度可达38.5 MPa,凝结时间为24 min。水泥主要水化产物是结构密实、结晶良好的柱形FeC2O4·2H2O,添加硼砂和三聚磷酸钠会使水泥出现孔隙,而硼酸会促进水化反应使水化产物结晶更优,且不会破坏水泥的密实度。 展开更多
关键词 铜渣 草酸 缓凝剂 抗压强度 凝结时间 水泥
粉煤灰基地质聚合物混凝土和普通混凝土温室气体排放量的对比研究 预览
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作者 蒲云辉 王清远 +2 位作者 李文渊 张国敏 杨平 《混凝土》 CAS 北大核心 2019年第4期10-13,共4页
因普通混凝土用水泥作为胶凝材料致使其温室气体排放量高。粉煤灰在碱激活剂的作用下可以作为辅助胶凝材料替代水泥拌制地质聚合物混凝土,该种混凝土具有降低温室气体排放量的潜力。对比研究生产1m3粉煤灰基地质聚合物混凝土和普通混凝... 因普通混凝土用水泥作为胶凝材料致使其温室气体排放量高。粉煤灰在碱激活剂的作用下可以作为辅助胶凝材料替代水泥拌制地质聚合物混凝土,该种混凝土具有降低温室气体排放量的潜力。对比研究生产1m3粉煤灰基地质聚合物混凝土和普通混凝土的温室气体排放量。研究表明:地质聚合物混凝土的二氧化碳当量要比普通混凝土低15%,地质聚合物混凝土的温室气体排放主要集中在碱激活剂的制备和后期高温养护,约占总排放量的90%。 展开更多
关键词 地质聚合物 温室气体 二氧化碳当量 水泥 混凝土
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大型铁路项目水泥供应计划管理 预览
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作者 赵兴龙 《中国铁路》 2019年第1期50-54,共5页
大型铁路项目的线路较长,通常设置多个搅拌站,施工需要混凝土方量很大而且需在短时间内密集施工,水泥供应经常出现不平衡不充分的问题。为了避免水泥供应问题影响项目施工,做好水泥供应计划非常重要。首先,将大型铁路项目的相关数据进... 大型铁路项目的线路较长,通常设置多个搅拌站,施工需要混凝土方量很大而且需在短时间内密集施工,水泥供应经常出现不平衡不充分的问题。为了避免水泥供应问题影响项目施工,做好水泥供应计划非常重要。首先,将大型铁路项目的相关数据进行分析,作为提报供应计划的依据,提升供应计划的准确性;其次,以水泥厂物流配送收益最大化作为目标函数,构建物流配送优化模型,引入惩罚系数,确保水泥厂优先考虑满足站点的警戒库存和均衡安排供应计划,保证供应计划的执行力;然后,考虑到特殊情况下的供应计划安排,给予不同的供应计划选择建议。以郑万铁路H标段为例,验证数据分析和优化模型的可行性和适用性。 展开更多
关键词 水泥 供应计划 库存预警 优化模型 惩罚成本
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碳纤维增强脱硫灰基保温干混砂浆的性能试验研究 预览
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作者 王朝强 梅绪东 +4 位作者 熊德明 何敏 张春 张思兰 王丹 《矿产综合利用》 CAS 北大核心 2019年第2期98-102,共5页
利用流化床脱硫灰作为部分胶凝材料,外掺轻质骨料漂珠,制备出了脱硫灰基轻质保温型干混砂浆,本论文研究了脱硫灰、漂珠掺量等与砂浆性能之间的关系。并优化体系较佳配比。结果表明,水灰比为0.53、内掺30%脱硫灰、外掺15%生石灰、轻质骨... 利用流化床脱硫灰作为部分胶凝材料,外掺轻质骨料漂珠,制备出了脱硫灰基轻质保温型干混砂浆,本论文研究了脱硫灰、漂珠掺量等与砂浆性能之间的关系。并优化体系较佳配比。结果表明,水灰比为0.53、内掺30%脱硫灰、外掺15%生石灰、轻质骨料漂珠替代河砂24%、胶砂比为1:1.7后的干混砂浆保温性能优良,容重轻质,28 d抗压强度为23.1 MPa,且砂浆保水率、2 h稠度损失率与凝结时间分别为98.7%、7.6%和5.7 h,各项性能均满足GB/T 25181-2010中的标准要求。 展开更多
关键词 水泥 脱硫灰 漂珠 干混砂浆
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基于识别算法的水泥矿山岩性分析 预览
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作者 Bulent TUTMEZ 《中南大学学报:英文版》 SCIE EI CAS CSCD 2019年第3期719-727,共9页
在任何工业原料场地特征的研究中,对水泥原材料进行岩性评价的研究均包括其物理特征、粒度和化学组成的相关描述。为了按照要求规格提供水泥组分,需要对水泥原料坑进行分类。采用监督模式识别分析法在采石场阶段的空间系统中进行识别。... 在任何工业原料场地特征的研究中,对水泥原材料进行岩性评价的研究均包括其物理特征、粒度和化学组成的相关描述。为了按照要求规格提供水泥组分,需要对水泥原料坑进行分类。采用监督模式识别分析法在采石场阶段的空间系统中进行识别。通过使用四种识别分析算法,基于主要化学成分如氧化钙(CaO)、氧化铝(Al2O3)、二氧化硅(SiO2)和铁(Fe2O3),在石灰石,泥灰质石灰岩(钙质泥灰岩)和泥灰岩三个层面进行岩性分类。结果表明:识别算法可以作为水泥采石场识别中的强分类器,而且该条件和混合分类器比传统的识别算法效果更好。 展开更多
关键词 水泥 识别分析 岩石学 矿山
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浅析套损井治理技术 预览
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作者 陈海涛 《化工管理》 2019年第33期84-85,共2页
油田油水井的套管损坏通常简称为套损,是指油田开发过程中由于遭受外力作用和腐蚀,釆油井及注入井的套管发生塑性变形、破裂或腐蚀减薄至穿孔破裂的一种现象。国内外的很多油水井都存在严重的套管损坏现象,并且有的非常严重,使得油田产... 油田油水井的套管损坏通常简称为套损,是指油田开发过程中由于遭受外力作用和腐蚀,釆油井及注入井的套管发生塑性变形、破裂或腐蚀减薄至穿孔破裂的一种现象。国内外的很多油水井都存在严重的套管损坏现象,并且有的非常严重,使得油田产量下降甚至直接导致油水井报废。对目前常用套损井治理技术进行了介绍和分析,为套损井治理的作业提供借鉴。 展开更多
关键词 套损 治理 固井 水泥
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A modified wire-loop snare technique for the retrieval of a large cardiac cement embolus caused by cement leakage after percutaneous vertebroplasty
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作者 Fei Teng Xin jian Xu Qiang Liu 《介入医学杂志》 2019年第1期38-41,共4页
Percutaneous vertebroplasty(PVP) is an interventional radiological procedure involving the injection of bone cement(polymethylmethacrylate) into a fractured vertebral body to remodel the vertebral body and relieve lum... Percutaneous vertebroplasty(PVP) is an interventional radiological procedure involving the injection of bone cement(polymethylmethacrylate) into a fractured vertebral body to remodel the vertebral body and relieve lumbar pain. 展开更多
关键词 TECHNIQUE CARDIAC CEMENT
如何做好水泥设备监造工作 预览
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作者 齐跃 《水泥技术》 2019年第3期51-58,共8页
阐述了水泥设备监造工作的意义,介绍了监造工作的方法、流程和如何编制监造计划,并用实际案例进行了解读。只有充分了解被监造设备结构特点,掌握相关检验标准和技术方法,按照监造计划实施,不断总结经验,才能取得良好工作效果。
关键词 监造计划 检验项目 有效监管 现场见证
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Hydrothermally induced diagenesis:Evidence from shallow marinedeltaic sediments,Wilhelmoya,Svalbard 预览
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作者 Beyene G.Haile Urszula Czarniecka +4 位作者 Kelai Xi Aleksandra Smyrak-Sikora Jens Jahren Alvar Braathen Helge Hellevang 《地学前缘:英文版》 CAS CSCD 2019年第2期629-649,共21页
Sedimentary basins containing igneous intrusions within sedimentary reservoir units represent an important risk in petroleum exploration.The Upper Triassic to Lower Jurassic sediments at Wilhelm?ya(Svalbard)contains r... Sedimentary basins containing igneous intrusions within sedimentary reservoir units represent an important risk in petroleum exploration.The Upper Triassic to Lower Jurassic sediments at Wilhelm?ya(Svalbard)contains reservoir heterogeneity as a result of sill emplacement and represent a unique case study to better understand the effect of magmatic intrusions on the general burial diagenesis of siliciclastic sediments.Sills develop contact metamorphic aureoles by conduction as presented in many earlier studies.However,there is significant impact of localized hydrothermal circulation systems affecting reservoir sediments at considerable distance from the sill intrusions.Dolerite sill intrusions in the studied area are of limited vertical extent(~12 m thick),but created localized hydrothermal convection cells affecting sediments at considerable distance(more than five times the thickness of the sill)from the intrusions.We present evidence that the sedimentary sequence can be divided into two units:(1)the bulk poorly lithified sediment with a maximum burial temperature much lower than 60-70℃,and(2)thinner intervals outside the contact zone that have experienced hydrothermal temperatures(around 140℃).The main diagenetic alteration associated with normal burial diagenesis is minor mechanical plastic deformation of ductile grains such as mica.Mineral grain contacts show no evidence of pressure dissolution and the vitrinite reflectance suggests a maximum temperature of~40℃.Contrary to this,part of the sediment,preferentially along calcite cemented flow baffles,show evidence of hydrothermal alteration.These hydrothermally altered sediment sections are characterized by recrystallized carbonate cemented intervals.Further,the hydrothermal solutions have resulted in localized sericitization(illitization)of feldspars,albitization of both K-feldspar and plagioclase and the formation of fibrous illite nucleated on kaolinite.These observations suggest hydrothermal alteration at T>120-140℃at distances considerably further 展开更多
关键词 DIAGENESIS SILL INTRUSIONS Hydrothermal convection cells Carbonate cement Sericitization of FELDSPARS
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Mechanical Properties of Micro-regions in Cement-based Material based on the PeakForce QNM Mode of AFM
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作者 任梅 施韬 +1 位作者 David J.Corr Surendra P.Shah 《武汉理工大学学报:材料科学英文版》 SCIE EI CAS 2019年第4期893-899,共7页
In this paper, the cement paste and the mortar were tested using the PF-QNM technique. It is shown that the PF-QNM technique is very powerful to characterize the mechanical properties of micro-and nanostructures in th... In this paper, the cement paste and the mortar were tested using the PF-QNM technique. It is shown that the PF-QNM technique is very powerful to characterize the mechanical properties of micro-and nanostructures in the cement-based materials. It does not have strict requirements for test environment and it does not damage the surface of the material. High-resolution images can be obtained very easily, and they can be analyzed statistically. The test results show that PF-QNM analysis can test not only the mechanical properties of the cement paste, but also investigate the interfacial regions in the cement-based material, including the variation in the mechanical properties of interface regions and the extension of the interfacial regions. During the test, care must be taken to choose the size of test area;indeed, a test area too small is not representative but too large leads to lack of stability. The recommended side is a square with a length of in the range 10-30 μm. 展开更多
关键词 PF-QNM peakforce TAPPING AFM cement PASTES mortar Young's MODULUS interface micro-and NANO-STRUCTURE NANOINDENTATION
不同温度条件下缓凝剂对水泥凝结时间的影响 预览
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作者 石新波 《低温建筑技术》 2019年第1期9-10,共2页
文中研究了蔗糖、葡萄糖酸钠,三聚磷酸钠三种常用缓凝组分在20,30、40℃条件下对水泥净浆凝结时间的影响。研究结果表明,随着环境温度的升高,水泥净浆凝结时间显著降低;三聚磷酸钠对温度的敏感性相对较低,但其缓凝效果也相对较低;随温... 文中研究了蔗糖、葡萄糖酸钠,三聚磷酸钠三种常用缓凝组分在20,30、40℃条件下对水泥净浆凝结时间的影响。研究结果表明,随着环境温度的升高,水泥净浆凝结时间显著降低;三聚磷酸钠对温度的敏感性相对较低,但其缓凝效果也相对较低;随温度的升高,蔗糖和葡萄糖酸钠的缓凝效果显著降低;在高温、高掺量条件下,葡萄糖酸钠的缓凝效果明显优于蔗糖和三聚磷酸钠。 展开更多
关键词 水泥 缓凝剂 温度 凝结时间
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地质钻探中坍塌破碎地层钻进护壁方法初探 预览
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作者 白闰平 谷宏海 刘海宇 《山西建筑》 2019年第18期67-68,共2页
分析了目前常用的地质钻探钻进护壁方法,主要包括了化学措施和物理措施两大类方法。结合地质钻探中现有的护壁方法,提出了一种钻进护壁的新方法,新方法主要包括:喷浆设备的发明和喷射浆液的选择。
关键词 钻孔护壁 地质钻探 喷射浆液 水泥 环氧树脂
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